Brain Science – Episode #25

The science behind caffeine

featuring Danielle Rath of

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Today’s episode features our very first guest. We’re joined by Danielle Rath, a notable expert and product developer in the caffeine and energy drink industry. Danielle is the founder of GreenEyedGuide Research and Consulting where she shares science-based information about energy drinks and caffeine, and helps people and companies where fatigue and caffeine use are prevalent. In this lengthly episode, we talk through all aspects of the science behind caffeine — its chemical structure and half-life, where and how it’s being used, the good, bad, and the ugly, as well as practical advice for everyday consumption. If you consume caffeine of any sort, this is a must listen episode.


Notes & Links

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Mireille is giving a talk at Heartifacts in August — check out this blog post for details on her talk and ways you can win a free pass to the conference!


📝 Edit Transcript


Play the audio to listen along while you enjoy the transcript. 🎧

Well, I am so excited today, because for today’s episode we have our very first guest, and it’s on a topic I think that we all love and care about, caffeine. So let me introduce to you all Danielle Rath, otherwise known as the GreenEyedGuide. Hello, and welcome!

Hello! Thanks so much for having me. I’m so excited to be here.

You said everybody loves this, Mireille. I would say so in our Slack – we have a Slack community, everybody. So if you’re listening to this, we have a Slack community; you can join that, and it’s totally free. But we dropped the note, that we’re talking to a caffeine expert, and everybody came as if we had honey and they were bees.


They did, they did. Everybody got excited.

Dropped their notes, their – everybody has nuanced ways they use caffeine too, whether it’s tea, energy drinks, which we’ll go into all the details of that… But everybody has an opinion on caffeine, essentially. I myself have a gigantic cup of coffee in front of me right now, so clearly I have an opinion as well… But we all use it in, as Mireille says, adaptive and maladaptive ways, so… That’s fun.

Yeah. So Danielle and I actually go way back. We don’t need to talk about how far back we go, but I will say, I knew Danielle as an adolescent.

Danielle and I actually met – she might have funny stories about me, which again, we don’t need to go into… [laughter] When I coached Danielle as a gymnast, as an adolescent. So we met when I lived and was working on my doctorate in graduate school in Southern California. So after I moved away and continued on my degree, our paths intersected again when I got involved with Beach Body or started working out again after having my second child. So it was super-exciting, because Danielle worked in product development relative to some of the awesome products that Beach Body has, which helped me get healthy after having my daughter. So Danielle, as far as I understand, you have always loved science, as I know… Danielle very much liked to stay within the lines.

[04:12] Yes, yes… That’s a nice way to put it, thank you. [laughter]

But as far as I understand, what got you started studying caffeine was actually more so around when you went to college, and that you weren’t necessarily a fan of coffee, dare I say…

Yes, absolutely. And even to this day, my policy with coffee is the same as my policy with alcohol - I like it if it tastes like something else.

[laughs] That’s awesome.

So I never really liked coffee, and I don’t even like tea, and along came these energy drinks that were a source of caffeine, that actually tasted good, that had roughly the same amount of caffeine as a standard cup of coffee… And that was my saving grace all throughout college, all throughout grad school, when I was juggling full-time school work with part-time jobs, and all of the stress that goes along with that. Energy drinks were my saving grace, as well as my nerdy passion.

Yeah, and I think one of the things that is interesting, and why I really wanted to talk with you, is because I think there’s so much misinformation relative to energy drinks in particular. So for our listeners, if we can understand not just energy drinks, but also caffeine, and go “Is it okay? Can I use it? In what ways does it work well and in what ways does it actually hinder me from doing the good work, or the work I wanna do?”

Yeah, I think one of the trickiest things about studying caffeine and energy drinks is that there’s always been this temptation to bucket everything into “safe” or “dangerous”. Or “All energy drinks have this much caffeine, this much sugar, and these ingredients.” And the challenge is that if you look at the products on the marketplace, whether they’re powders or pills or liquids, that have caffeine in them, they’re all different.

So it’s always been very difficult to address questions about caffeine safety, or putting butter in your coffee, or “Do energy drinks kill people?” because there’s so much diversity in this field of caffeinated products… And some things that people think are very dangerous, like Red Bull, are actually weak sauce and less scary to me professionally than some of the drinks that people have never heard of, or drinks that people love, like Bang. So there’s the disparity in terms of the consumer perception and what I believe as a scientist is actually the biggest threat.

Yeah, so can you tell me what all drinks have you looked at in greater depth?

I’ve looked at so many of them… In 2006 there was like 500 energy drinks that came out alone that year… So I can never keep up with the new energy drinks coming out. I have a lot of fans on Instagram (thank goodness) that will send me pictures of the new stuff, and I’m always lagging behind. I don’t have my finger on that pulse. But I am always looking at the ingredients. So ingredient trends like branched-chain amino acids, combining creatine and caffeine, which is – don’t do that… CoQ10, taurine, carnitine, B vitamins… I’m looking more at what these ingredients do, how they interact with caffeine, and are these drinks that are hopping on board with these trends providing a big enough dose to actually be effective? Or are they just sprinkling it on the label to be like clickbait, to look attractive without actually doing anything.


Yes, buzzwords. Exactly.

Right. You mentioned diversity, so that means is caffeine generally the main vehicle that they’re selling?

Oh absolutely, yeah.

[07:57] …and then these other things are like cargo-culting onto or being added to, essentially… And your inability to really classify them is because what comes with caffeine often is so diverse that you’re not sure, or able to pin down the right kind of research that says “Okay, this is how it performs unanimously.” Because caffeine has sidecars, all the time.

Yes, absolutely. Because there’s two important points to that. One is that in most of these drinks caffeine is doing all the work. If you take the stereotypical energy drink, Red Bull - Red Bull is the stereotype everyone thinks of, because it’s the number one brand. Red Bull has caffeine, taurine, B vitamins. Caffeine is doing 90% of the work. Taurine is maybe affecting you, carnitine is maybe affecting you, B vitamins aren’t really affecting you unless you’re deficient… So caffeine is doing all the work here.

But then you have another energy drink that has caffeine, guarana, yerba mate, yohimbe extract - all these other things… So how do you call both of them an energy drink? And then on the converse, if there’s something that has caffeine from green tea and B vitamins, and a lot of sugar - can you call that an energy drink? Because it’s not exactly a tea, it’s not exactly a soda…

So this is why I often use the term caffeinated beverage, as opposed to energy drinks, because I feel like that’s a more inclusive terms that captures everything in the umbrella - the stereotypes and the energy drinks in disguise, as I like to call them.

I mean, because just taking B12 vitamin shots can be considered an energy boost; it boosts your energy, your thoughts, your mental clarity… People do that just for energy, is what I’m trying to say. They use it for those reasons.

Yeah, there’s a lot of confusion around whether B shots actually work. There’s a huge placebo effect to that, where people expect that B12 gives you energy, and so people feel that energy, but this is perceived energy. So this is the energy rated on a scale, which is subjective. So it’s hard to actually know if it’s the placebo effect or if it’s really B12.

The people that have gotten energy from B12, like JFK, Margaret Thatcher - those people actually had an enzymatic deficiency, so they needed B12 shots. So their need actually drove that trend of high doses of B12 in drinks, and having those B12 shots or supplements. But the science behind whether or not that actually gives a perceived boost of energy is really inconsistent.

I’m so glad you mentioned that, because what you’re getting at is really genetic differences, right? People’s genes play a role in the way in which caffeine affects them…

Yes, yes…

…and that can be highly varied.

Absolutely. Absolutely. It’s everything from how quickly your body metabolizes caffeine, to how sensitive you are to anxiety. There are people that have polymorphisms or differences in their A2 receptors in their head… So the way that adenosine affects them in their brain is different, and the way that they are naturally more anxious is different. So they’re more susceptible to caffeine because of those genetic differences.

So there’s that, and then there’s caffeine sensitivity, which makes some people, like my husband, super-sensitive to caffeine… He has a cup of green tea and he’s running around the house like crazy, whereas me - my sensitivity is a lot lower. I’m a lot less sensitive, so I need a lot of a stronger dose.

Does that mean you build up a tolerance over time, or is that just like – some of that’s built in, some of that’s built up…?

They are related, but they’re slightly different. So your caffeine sensitivity will always be the same. You will always have no effect on caffeine if you’re not a responder, and you will always have a high tolerance if your sensitivity is low. You can’t change your sensitivity, but you can change your tolerance.

[11:53] If you’re someone that always has negative side effects to having caffeine, whether it’s from soda, or chocolate, or tea, then your tolerance isn’t going to change that very much. If you’re someone that can have a cup of coffee and you feel that alertness, then your tolerance means that having a cup of coffee every single day for a year - you might need two cups of coffee, or you might need three cups of coffee.

So I would say tolerance is kind of like a fine-tune on your sensitivity. Your sensitivity is where we start, and then you can kind of fine-tune that up or down by building a tolerance.

I’m so glad you mentioned that, Danielle, because in my preliminary research of this - understanding how we metabolize caffeine is really big, and so the sensitivity is one aspect of that, tolerance is another… But I’ve also found drug interactions can also make a difference, right?

Can you talk to us about – sort of certain drugs can affect it…?

Yes, there’s a certain class of drugs, that I always forget… It’s not like the statin inhibitors, but it’s basically the things that are supposed to control your blood pressure and your heart rate. If you’re on those types of drugs, then they can interfere with caffeine in a negative way.

Yeah. So you’re not supposed to have caffeine if you’re already on medication for blood pressure or heart rate.

So that gets at too the way in which caffeine can affect your heart, and how we hear some of these things over like “Oh, this person had three Red Bulls and they went into cardiac arrest.”

Yes. And there’s always this tendency to blame energy drinks when someone passes or is hospitalized because of a caffeine overdose, but a lot of times people digging into the research have found that person has a genetic something in their heart that made them more susceptible. That the dose of caffeine they had wouldn’t have affected someone without that genetic disposition the same way.

So is there any sort of scientific way in which people know about themselves, or is it literally just like trial and error?

Unfortunately it’s trial and error…

Oh, boy… [laughs]

I think that some of those DNA –

Like the 23andMe some of the DNA tests?

Yes! Thank you. I think some of those might have the ability to tell you if you have a sensitivity to caffeine, but I would say just save your money and always nurse your caffeine. If you’re not sure how caffeine affects you, don’t start by having three Red Bulls, or five NoDoz pills. You can figure out how caffeine affects you by going slow, and not having a huge dose right off the bat.

This is something we always prescribe too, is like “Be your own scientist”, essentially. That’s what you’re saying.

Yeah. Because that’s gonna be more reliable than whatever 23andMe has to say.

So I guess getting into that, what kind of effects, if you were being that scientist and you were doing some of these things, taking this advice, and you were nursing caffeine - not so much energy drinks, but caffeine drinks, as you say - what are the effects that give you indications that you’re on the bad side of sensitivity to caffeine? What are those feelings? Jittery, anxious, things like that…

Exactly. There’s three telltale signs that you might be having too much caffeine. One is if your thoughts are kind of racing. Caffeine is supposed to help you focus. If caffeine is not doing that, if it’s doing the opposite of that, and you feel like you have scattered thoughts, it’s probably too much caffeine.

The second one to look for is a racing heartbeat. Caffeine mildly affects your heart rate, similar to going up three flights of stairs. It shouldn’t kill you, but you might feel it. You might feel a little shortness of breath. So you can start to notice – and a lot of people are wearing Fitbits these days, so you can look at your Fitbit and see if you’re higher than normal. That would be a second easy sign to look at.

And then the third sign would be those jitters, if you’re actually feeling some slight trampling. It’s usually your hands. Sometimes it could be like not able to hold still with your legs; if you start tapping your foot incessantly, that’s another sign that maybe you’ve had too much caffeine.

[16:00] And you mentioned genetic disabilities or genetic indicators to, say, adverse effects with caffeine… What about autoimmune disorders, or things regarding metabolism, things that people may have or not be aware of. Almost everyone has some sort of thyroid skew towards the negative side… And when I say “everyone”, I mean everyone in America.

Or someone that adopts the kind of diet we generally have here, because we eat lots of unique, weird things… And there’s a lot of thyroid issues, or metabolism issues, obesity even… How does caffeine favor into those classifications of people? Or is that too wide and diverse for you to drive into?

It’s a little wide and diverse. The areas that caffeine affects is not typically autoimmune disorders, or even obesity. To my knowledge, there’s not a direct interaction between caffeine and these things.

One of the things that I’ve found that was super-interesting was that caffeine is an alkaloid… To geek out for a moment.

Oh, yeah. [laughs]

Right? And that morphine and nicotine are also alkaloids. Is that right?

Does that make any difference? I mean, is that disconcerting, or in what way is morphine different than caffeine, or what is the mechanism of action that then sort of works on our bodies to sort of stimulate or increase our attention, or stimulate what, in our brain?

So the way that caffeine works has more to do with its specific shape than its class as an alkaloid.

As far as I know - I mean, there’s always new research; it’s so hard to keep up with this stuff…

Right? Always…

Yes. So initially, a lot of people were looking at “Is this why caffeine is so addictive? Is it addictive because it shares the same class as morphine or some of these other alkaloids that have these addictive properties? But that research is leaning more towards the no, that caffeine is not addictive in that same way… And the way that caffeine helps you stay alert, the way that caffeine works is because its shape is so similar to something called adenosine, that it basically sits in adenosine’s throne and keeps adenosine from doing its job. Adenosine can’t do its job unless it’s sitting on its throne, and caffeine is sitting there, blocking it. So adenosine’s job is supposed to calm us down…

I have this filter on my phone that turns things in this nice shade of red when it’s time to simmer down and get ready to go to sleep. Adenosine is like that. It’s like “Yo, it’s been a long day. Let’s start relaxing, let’s get ready for sleep”, but caffeine sits in that spot, so you never get that calm-down signal. Instead, you’re like “Woooh! More work! Let’s go, let’s go!”

I love this. And I quote, you said “Caffeine blocks adenosine, which prevents adenosine from sending you ‘You are getting sleepy’ signals.”

Yes, yes.

But after a while, your body realized caffeine is blocking adenosine, and makes more… So it takes more caffeine to feel the same energy boost, right?

This is tolerance, right?

Yes, exactly. This is where the tolerance comes into play, exactly.

So this is why going, you know, my standard cup of coffee, when I’m tired, because I didn’t sleep, or God forbid, my sleep was interrupted with a newborn…

…that it’s like “Wait, I need more. I need more.” So that might be, to some degree, why it’s confusing for people relative to addiction, right?

And tolerance is a facet of addiction; you need more to cultivate the same effects.

But that doesn’t necessarily mean caffeine is addicting, it just means we like it.

Well, what is addiction then, in that case? How do you classify addiction when it comes to caffeine?

Mireille, you probably can answer this better than me though, so I’ll let you… [laughter]

Well, because when is it ever that simple when it comes to our brain, right?

[20:08] It’s not, yeah.

There’s multiple systems working. And to say “Well, adenosine…” that’s one thing, but dopamine is another. So I can talk about other drugs and how they actually burn out dopamine receptors, sort of similar to this adenosine, and going it blocks, so that dopamine just keeps giving you the hit, over and over, which is why you never will have the same sort of effect using the drug as you did that first time, when you had a pure altered state, right?

Right. In our pre-call, talking about this subject, you mentioned chasing the ghost…

Yes. Well, that relative to addiction, and going – you know, that’s a commonly used phrase, to go “Once you’ve used, you’re never going to be able to catch that ghost again, because you had an unaltered brain prior to when you first used whatever substance.”

Mireille, didn’t you also use an acronym in a previous podcast? It was like CAR, or something…

Yeah, so I… Dude, like Cue, Craving, Response, Reward.

So cue, anticipated response, reward. But, so there’s multiple systems involved with our reward system, and adenosine is not dopamine, right?

Yes. I remember listening to that podcast and having to pull over and take notes on my phone…

Oh, boy… I love it.

Because caffeine - one of the many things it does is it boosts our dopamine. So this is related to why having a cup of coffee feels so good, in addition to that mental aspect of this reward, like “Yes, I’ve survived another morning with the kids. I’m gonna have my cup of coffee.” You feel like that’s a reward, so there’s that aspect of it, as well as the actual signaling of the dopamine that caffeine is up-regulating.

Right? So it’s interesting, relative to the behavioral conditioning… We practice – like, we are what we repeatedly do, and our brain loves the familiar; it’s like “Oh, my cup of coffee…” So there’s multiple systems at play when I’m going for my caffeine… Which is part of why it’s so hard to stop, because it’s like “But it feels so good.”

Right. Some people have routines, and mine has generally been one cup of coffee a day now. I don’t know what happened… It used to be two or more. Maybe I’m lazy, or busy - I’m not sure which one it is. I’ll probably favor I’m lazy – I’m busy. I almost outed myself there…

Nice Freudian slip there…

Yes, it was an accident there. But you know, my day begins with a cup of coffee. So is it addiction? Going back to the question “When is it addiction?” Well, I don’t think so… Because that’s my habit loop. I run that play, my day kicks off, my brain, all the focus, all the things come into play and say “Now it’s time to work. Now it’s time to go get busy and do our things”, or whatever it is, and that’s my go signal. That’s the shot in the air in the runner’s run.

Yeah, so it was interesting speaking to that, because when I did a period of sort of eliminating a lot of foods - I did this elimination diet - I had to get rid of caffeine… But what it revealed was actually a way in which I used caffeine was even more so a reward… To go like “Oh, if you do these other things at the end of your day, Mireille, you can get this awesome coffee. You can have your latte that you love so much.” So at that point it wasn’t for the caffeine benefits, it was for the pleasure circuitry.

Yes, absolutely.

Which I was like “Hey, Mireille, what are you doing?” My nice internal dialogue, I’ve just made external…

And truthfully, lattes - if you go in a Starbucks, or a decent, high-class coffee place, in many cases these things aren’t just simply coffee, they’re desserts. If you get a latte, you’re gonna put caramel syrup in there potentially… You may not, but there’s the temptation to add – you know, with breve, or different things like that, to spice it up, and it’s not just simply caffeine/coffee or the reward, now it’s kind of a dessert, in some cases…

Yes, which gets into the problem of caffeine and sugar.

You must seriously read my mind… [laughter] Like, yes…! It was really interesting - there was research from the Harvard School of Public Health that found that there was six genetic variants associated with the way in which people metabolize and form an addiction to caffeine. So of this 120,000-person study, there are two genes related to how caffeine is metabolized, two genes associated with how we feel rewarded from ingesting caffeine, and two genes that regulate fat and sugar in the bloodstream as a response to caffeine. So sugar and caffeine - there’s all of these interwoven things that make such a significant difference.

Yes, absolutely. I remember reading that study but a lot of the details have kind of gone out of my mind, replaced by other stuff… [laughs]

Yeah, but every energy drinker, any caffeinated beverage has a different intermix of caffeine, juice and sugar, right?

Yes, yes. And carbonation.

And carbonation… So can you talk to our listeners about how do those things matter, what are those variables?

So the most important thing to keep in mind is that if you are drinking caffeine, you probably are doing that to feel more alert. If you have caffeine and sugar, your goal will backfire. That caffeine will not be as efficient at helping you stay awake, if there’s sugar involved… Because the sugar will create a blood sugar spike and a blood sugar fall, and that crash is often confused with an energy drink crash or a caffeine crash… But really caffeine doesn’t do anything quickly. It takes a while to kick in, and it takes a long time to leave.

So if you’re feeling this energy spike and then crash, it’s because whatever you had had a lot of sugar, which is behind this fall. This is why I never drink caffeine and sugar. I try and get my sugar-free syrups if I go to a coffee store, and I stick to the sugar-free energy drinks… Because in a few different studies they’ve found people that had both caffeine and sugar were more tired after two hours than the people that had caffeine alone.

So that would also play into anything… If I’m adding sugar to my coffee, or latte, or frappucinos, or things like that, right?

It’s not really going to cultivate the benefits that I want it to.

And in some cases - or in many cases - the buzz is from sugar.

When you put - I’m just guessing - 80 milligrams or more of sugar into your body… That’s probably conservative on those kind of drinks. It’s probably a lot more than that.

I think the American Heart Association says that adult men can have 36 grams of sugar in a day, and adult women can have 26 grams of sugar in a day… And I’ve seen energy drinks that have 68 grams of *organic*, natural sugar…

This is like three days’ worth of sugar for you… And they have high doses of caffeine, too. If you’re trying to be awake, all you need is the caffeine. Let the caffeine wake you up, not the sugar.

So are you advocating for brown coffee then? Or should I say black coffee… Because I know some people out there who are like coffee snobs will say “This is brown coffee, not black coffee.” So are you advocating for just plain coffee?

I’m advocating for energy drinks that don’t have sugar or a high amount of caffeine…

[28:13] [laughs] Right…? But sugar is a huge variable in that. I find it humorous, and we’ll see the long-term benefits, because my kids have stopped asking for dessert; they just ask for sugar.

Oh, no… [laughter]

They’re like “Well, I’ve already had my two sugars for today”, or whatever…

Like little sugar cubes?

No, but they actually – because I feel like education is so important, and going “What we ingest, and managing that relative to what we’re trying to optimize for”, so helping even my kids understand that sugar affects them, and that 25, 26, 36 milligrams… I mean, what does a Coke have in just a regular 16-ounce? More than that. More than the daily allotment.

Yeah. Some drinks are pretty bad, yeah.

Right? And so energy drinks - it’s not uncommon to have 25, 26, 35 milligrams in one.

Grams. It’s grams in sugar, milligrams in caffeine.

Oh, gotcha. Yes, thank you. This is why we have the scientist.

Yeah. I said milligrams, too.

That’s alright.

Grams, not milligrams.

Yeah, so this problem of having high sugar with caffeine, whether the caffeine is high or low, is a problem that I am observing in energy drinks, as well as teas. One of the popular teas - I think it’s Snapple or Lipton… I mean, you think it’s healthy because it’s tea, but it has so much sugar that you’re better off having an energy drink with no sugar, like this yerba, that has no sugar, but it has its caffeine from a natural source, which is yerba mate.

There’s so many alternatives – even if you don’t like energy drinks, there’s these other caffeinated beverages that aren’t exactly coffee, black or brown, and the tea, black or green… It’s just other source of caffeine that don’t come with that sugar. Because this high-sugar problem is in all these caffeinated beverages, not just the energy drinks.

Which speaks to the motivation factor. This is one thing I said to Mireille - what is the motivation behind these food manufacturers to create these drinks? It seems like you may be aware of some that have good intentions for the consumer, which is the person drinking it, or eating it, or consuming it, or whatever, to have the effects intended by taking in caffeine, or potentially sans sugar, or whatever other things, or the sidecar, to do what it’s supposed to do or what you desire it to do. Whereas maybe – I’m not calling out Red Bull, because theirs is so well-known, but brands like that, that are in the energy drinks space, that get this negative hype about who they are, what they do, their intentions… What is the motivation for most of the people (I say people, but companies) involved in creating these products? What are their goals?

Obviously, I can’t speak to all companies, but speaking as a product developer, oftentimes you are forced to give the customer what they want, as opposed to what you wish they wanted. So for example, I know as a food scientist that 36 grams is too many grams of sugar. But my boss knows that if I put 36 grams of sugar, the drink is going to sell. So oftentimes people are put in this situation where they have to put larger doses of caffeine, very large doses of sugar, because caffeine is bitter; caffeine tastes horrible by itself. You need some kind of sweetener… And there are some people that would rather have natural sugar, even if it’s two days’ worth, as opposed to artificial sweeteners.

[31:53] So you’re kind of chasing how to make the product not taste horrible, and how to make a product that sells. And oftentimes that runs into your personal beliefs or your personal motivation, but the end goal is to make a product that’s good, that sells, and I feel like that’s consistent across the industry.

So if you deliver the drink with not 36 grams, you delivered it with – what would you desire with? Like, if you were making it for something, and you wanted them to “enjoy”…

10 grams.

10 grams. How would they then take it in? So if you delivered it the same way, but not 36 grams, but 10 grams instead, how would the consuming body that you’re serving take that product?

If you have 10 grams or less of sugar, that blood sugar spike won’t be as dramatic… So you can still get the benefits of the caffeine without the defects or without the side effects of that increase in sugar. And there are plenty of caffeinated beverages, both teas and coffees and energy drinks that have tried to offer this healthy formula, they just don’t sell as well.

So there are people out there that are trying to provide these options, and I think they taste pretty good. They’ve got 10 grams of sugar, maybe 80-100 milligrams of caffeine, they may or may not have artificial sweeteners, they may or may not have artificial colors, B vitamins… But this is an energy drink, but it’s an alternative to the stereotype, and it tastes good, it’s just not as popular.

Yeah. Are they reading the label, or are they trying it and not liking it? What do you know about the deciding factor there? Are they like “Oh, this has got 10 grams, so I don’t like it” or is it “I tasted, I tried it. The effects didn’t do what I thought it should do. I’m not gonna buy that one anymore.”

Very few people actually read the labels… So it’s more about brand awareness, what have you heard that works, and if you’re spending $3 for a caffeinated beverage, is that gonna give you the most bang for your buck? Is this actually gonna wake you up? And safety. Like, what do people hear on the news? So brand awareness, and people’s consumer preferences - what drinks they pick - is largely based on brand awareness, more than reading labels.

And so with that, is it necessary that – I mean, I don’t see it on my cup of coffee relative to how much caffeine is in it… Is that right? There’s no regulation to say “Hey, this has to go on”, whatever you’re drinking, for how much caffeine is in it, right?

This is a huge pet peeve of mine actually, and I’m so glad you brought this up. With the energy drinks space, or – well, more energy drinks than caffeinated beverages, the whole umbrella - energy drinks have these guidelines from the American Beverage Association that says “You should put a warning label on it, you should say how much caffeine is in your beverage from all sources, and you should try and limit the amount of caffeine in your drink. But coffees don’t have to do that, and teas don’t have to do that. So a lot of people don’t know that the Starbucks triple-shot they’re having has three times the caffeine as a Red Bull…

..because coffees aren’t beholden to the same guidelines.

Wait, wait, wait. Say that again, so that our listeners get it.

Starbucks triple-shot has three times the caffeine as a Red Bull.

So how much caffeine is that?

That’s 225 milligrams, and Red Bull just has 80.

Wow…! That’s a lot, right?

So what is recommended, for how much? How much caffeine can people have every day, so that I know what limits am I trying to stay within?

So if you are pregnant or nursing, you can have 200 milligrams a day, which is two cups of coffee. If you’re a healthy adult, no known predispositions, no known hard defects or any ailments like that, you can have 400 milligrams a day, which is four standard cups of coffee.

Yes… [laughter]

Almost everybody listening is like “Thank you. Thank you. You didn’t tell me I was killing myself. I appreciate that.”

And I would recommend checking everything you drink, and everything you eat, through this website called It has the largest database of foods, and drugs, and drinks, like sodas, as well as coffees and teas and energy drinks. They will tell you how much caffeine is in your drink, which is very helpful when you’re getting a latte from Starbucks and you don’t have the amount of caffeine on the label.

[36:29] Right. Do you know much about how much caffeine you get out of the beans? Starbucks isn’t saying – maybe they are saying, I don’t know; I’m assuming that they’re using the same kind of bean, to some degree, that everybody else can get off the shelf, except for they probably own the farm… The bean being the coffee bean; it originates as a cherry, it has a process to become the bean that you can actually grind up and turn into coffee by doing a process of [unintelligible 00:36:56.19] and all this stuff to get the coffee out of it, whatever - all that science; you may know more about it than I do. I’m just speaking as a coffee geek. But the point is that there’s ways you can extract the coffee out of the bean, that extracts maybe more of less caffeine. Are they just doing a process that gets the maximum amount of caffeine, or is it just by nature that espresso is naturally more caffeinated?

There’s a lot of different factors that dictate how much caffeine you get out of the bean. And we’re not just talking Arabica versus Robusta beans, we’re also talking the water temperature, which is why cold-brew is a thing. Cold-brew, instead of getting the caffeine out of the bean using hot temperatures and short times, they get the caffeine out using cold temperatures and very long times, like several days. So that is affecting the amount of caffeine that’s coming out of the bean. And also French press is different, and drip is different… This is why it’s very difficult to generalize and say a standard cup of coffee has 100 milligrams, because it’s like “Well, how did you make this cup of coffee? Is this the gas station or is this Starbucks? Because it’s gonna change, it’s gonna differ.

The process. There’s a lot of stuff involved.

Right. I was even surprised that in researching Dunkin’ Donuts decaf, decaf had a fair amount of caffeine.

Yes, it’s not zero. It’s not zero. [laughter]

Right… So it makes it hard for consumers to figure out, unless they’re really deliberate, right?

..and going “That’s just it, it requires a filter.” No pun intended. [laughter]

Well, it requires some significant education to consume products these days, whether it’s like you’re buying the bean, grinding it yourself, and choosing one of several processes, or going to Starbucks, or going to X. There’s so much consumer education that just doesn’t happen… And as you said, coffee is not coffee is not coffee. I can make a French press, I can make an espresso, same beans maybe even, and have different caffeine levels based upon the brew process.

The strongest two reasons why I do what I do are 1) because people don’t know how much caffeine they can have in a day (400 milligrams), 2) they don’t know how much caffeine is in what they’re drinking. And again, this is why I prefer energy drinks, because there’s more of an industry standard to tell you on the label how much caffeine is in there, versus if you get those glass bottles of Starbucks cold-brew, which are really popular right now, people don’t realize that cold-brew is stronger, and they don’t realize how much caffeine is in that jar… Because it’s a coffee, and there’s no regulation that says “You have to label it.” If it comes from a natural source, you aren’t required to label it. So those are the two big gaps.

What’s the average for that one?

Oh gosh, you’re testing me… I wanna say it’s 280. It’s somewhere around 280 milligrams.

[39:58] And that’s because you tested it, or someone tested it; it’s not on their label, right? Because you said coffee doesn’t have to label the caffeine amounts.

No, it’s not on the label. I think that was another caffeine informer to the rescue.

Yeah. We can fact-check later, it doesn’t have to be perfectly accurate, but some range… 200-300, somewhere in that range is probably pretty accurate.

Yeah, 200 to 300.

It’s high, is the point.

It’s high, yeah.

So can I ask - what about certain drinks, like Bang…? We already know Bang as an energy drink is the max right there for caffeine…

Just based on the brand alone it’s gonna be max, right? Like “Bang!” [laughter] Of course… They did well on the branding front.

But they also have a keto coffee… So is that the same amount as the regular Bang, which I believe you said is somewhere around 350 milligrams in one can?

Oh, that’s the one can I don’t have up here next to me.

I’m gonna narrate for a second… Danielle is looking to her right; she has a caffeine drink collection to her right. I’m assuming some of them are full – no they’re all empty.

They’re all empty.

But she’s referencing literal cans to her right.

Yes… [laughs]

And she’s holding one [unintelligible 00:41:08.16]

So I don’t have a can of Bang next to me, because I hate giving them my money. I don’t buy their products. But a typical can of Bang has 300 milligrams of caffeine. I’m not familiar with their keto coffee ones, but I think it’s similar.

You know, the keto label though brings a lot with it, too. People who look for that label and buy those products are really scrutinizing, to some degree - unless they’re just like on the bandwagon, and they’re just like “If it says keto, I eat it, I consume it, I take it. Whatever. It’s good.”

I think it’s a mix.

So there’s two different people that are involved with ketogenic-based diets, and ketogenic-based products - is educated, reading the label, or uneducated, “It says keto, I can eat it.” [laughter] Those are the two camps.

Right? But I think about that with everything, because – like, years ago it was the low-fat, or low-carb, and then I don’t look any further than that… You want to dig a little deeper if you want to know – if you’re really being your own scientists and going “How does this affect me? What happens in my brain? Is it working for me?”

Yeah. I said to Mireille on our pre-call – I said it doesn’t have a mom or a dad, the thing I’m consuming… And she laughed, and I don’t know why she laughed, but that’s a thing, I guess… When you consume something, you ask “Did it have a mom or a dad?”

Right? Like, is it a plant or an animal of sorts? Like, did it have some sort of origin?

Or was that made by a human? Like, that’s not a mom or a dad, that’s manufactured.

Right? I’m like, “Dorritos!” Dorritos don’t have a mom or a dad.

Well, Oreos are healthy because they’re vegan? Well, you know… [laughter]

Or a little plastic, maybe… No offense, Oreo…

I know. This is why I have some trouble following labels… Because not everything that’s natural is better than something synthetic. It’s not inherently better because it’s natural. And also, things aren’t inherently healthier for you because it fits a specific diet type.

Yeah, one of the things that I appreciated was in your product development when you worked with Shakeology is that you actually had to go look up ingredients, because they really care about where they source things from, right? And how then you put that together to make the product that you’re selling.


And it matters, doesn’t it?

It really does. The biggest, best example of this is that if you take something like stevia, which is like the best natural sweetener - I’ve tasted so many different samples of stevia in water, and some of them you get this awful, bitter, metallic taste. And some of them come from plants that can’t pass an audit, because they have poor cleanliness, or poor manufacturing standards. So there’s this beautiful, natural plant that becomes this awful thing you don’t want to eat, because the supplier isn’t following the manufacturing standards of cleanliness and good manufacturing.

[44:19] So we could dive deep into all of these –

The nuance.


…which I would love, but you know, it would require a lot more time…

Yes, yes.

But it’s valuable, right? …and teaching people to go examine what you’re ingesting.

Yes. I think you need to examine it, and you also need to know where you’re getting your things… Because weight loss supplements and workout supplements are among the most adulterated products on the market. So energy drinks often fall into that place, and if you were just buying an energy drink or a supplement off the internet, you don’t know a) if they have good ingredients, b) if they’re actually putting the right amounts of ingredients in there that they say on the label… So that’s a certain amount of trust, as well as your own due diligence involved.

Well, that leads us to regulation then. You mentioned supplements - that’s generally in the vitamin department, which is totally unregulated; you could be rogue out there. The regulation is…

…wishy-washy, let’s just say. It’s not there, fundamentally… So in this market, the FDA regulates, they don’t regulate - what’s the scenario between regulation of these kinds of things? No one says what you can and what you can’t do. In terms of the label, of saying caffeine or not… Same thing with supplements. You can make a claim. As long as you can’t say it saves your life, you can make a claim.

With the supplement industry I certainly learned a lot by working at Beach Body, because Beach Body was so atypical in how much diligence they put into their ingredients and their suppliers. So working in the supplement industry was really eye-opening, because we at Beach Body were doing so much hard work to guarantee our ingredients were safe, and actually what they said they were; they weren’t adulterated. But there was a lot of people that weren’t following that same adherence.

Like any industry, right? There’s variation.

There’s variation, exactly; like any industry, there’s always a spectrum of people that are doing the right thing, and people that are just making money for the wrong reasons. So with supplements the regulations are a lot more lenient. Of course, they have the same checklist, of like “This must be on your label, and if you’re putting an ingredient in your product, then you have to have this paperwork.” But no one’s gonna ask you for that paperwork, and no one’s gonna go into a store and check your label beforehand. Basically, I feel like in the supplement industry it’s “You do what you can until you get caught.” So hopefully, you’re doing the right thing.

That’s why we need people like you though. You’re an advocate. You’re an advocate for the consumer, right?

Yes, absolutely. I actually wrote a blog called “Confessions of a shady supplement supplier”, which was written in sarcasm to be like “This is how much stuff I can get away with.” The goal of that blog post is trying to educate people on how to read labels and how to make sure you’re buying from people that don’t have red flags all over their website or their label.

Well, I think that’s what I love about our audience. We are trying to get people to think differently. Think about what to think about, for one, and then two, investigate what lies beneath; so what are the things in the things we’re consuming, thinking, eating etc. And then more so, there may not be strict regulations out there in terms of like “Oh, this is what you can and what you can’t do”, but if we have advocates like you and companies like Beach Body etc. in other different areas that they specialize in, can they have a brand that’s focused on “Okay, we don’t need regulation, because we care so much about our customers that we are our own good regulators, and our brand is built upon this trust”, as you said before; you have to trust them. Then you sort of like weed out the shady people because the brand alone stands to test, and you’ve got advocates who advocate for them.

[48:23] So long as you’ve got people that are rooting for the consumer, and not just the shareholders or stakeholders, or the profit keepers of the businesses - if that’s what we’re optimizing for, we’ve gotta optimize for the consumer, and we need people to optimize for that and be advocates of it.


One of the things that I think is important too is - we talked about the crash relative to sugar, but how long does caffeine actually stay in your system?

It’s a couple hours, actually.

It could be 6-7 hours, because caffeine has a half-life of 3 – on the high side it’s more like 5 hours… So that’s how much time it takes for half of that dose to leave your body. So my problem with drinks that have a lot of caffeine is that – let’s say you have it at 3 PM, which is the hour most of us have our energy crash. So if you have a drink at 3 PM, with 300 milligrams of caffeine, then it’s basically the equivalent of having two cups of coffee at 10 PM, because that’s how much caffeine is left in your body. If you wouldn’t have two cups of coffee at 10 PM, you shouldn’t have an energy drink or a coffee with 300 milligrams at 3. That’s just how long it takes caffeine to leave your body. So yeah, it’s like 6-7 hours.

So it’s a math equation.

It’s a math equation.

So for our listeners to go “If at this time – what time do I want to go to bed? And how much of X drink will be left in my system at that point in time?”

Yes. So math is not my strong suit. As much of a scientist as I am, math is really tricky. And even it’s funny because people always talk about the half-life of caffeine, but I don’t know what happens – we don’t talk about the full life.

Right?! I’m familiar with that half-life, too… Because it’s all drugs; this is how long it lasts in your system.

Exactly. The LD50 and then the half-life. So it’s not like “This is how long it takes for 100% of caffeine to leave your body.” I don’t know. We just don’t talk about that. But the math that I do when I’m making choices for myself, and the math I recommend for your listeners is 1) look at how much caffeine is on the label, and divide that number by 2, and say “In three hours this is how much caffeine I’m going to have. Would I drink something with this much caffeine (the X divided by 2)? Would I drink something with this at three hours from now?” It’s easier to write it down. It’s kind of hard to talk through.

So the other thing with that is caffeine isn’t instantaneous in terms of its effects.

The placebo effect is right away, but it takes like 20 minutes to kick in… Because even though it does cross the blood-brain barrier, it takes a good 15 minutes to get to your small intestine, where it’s absorbed. And some of it - a lot of it - is absorbed through your stomach. But still, it takes time for that caffeine to get through your GI tract to where it’s absorbed, and then from where it gets absorbed to go to your brain, and your liver, and all the places it has an effect.

I just imagine your brain kicking off, like “Read all systems! Here comes the caffeine!” and all the necessary components, so your body was like, “Get ready for it!”, so they get ready for it; it’s like the instant placebo effect you get. They get ready for it… “It’s coming, it’s coming!” and then it arrives. [laughs]

I mean, I honestly feel better when I crack open my caffeinated beverage, because it’s like “Okay, I’ve got what I need to get through this day. We’re good.” Just the placebo, just the fact that I’m about to have it helps me–

The loops begin.

This is so much like a habit loop, of like I don’t actually have to have the dopamine hit before my brain is like “Send it! Send the troops!” [laughter] If only our brains could really speak, real-time…

[52:14] I know…

It would be fun… And annoying. “Stop doing that!”

One of the reasons that I wanted to have our listeners hear you is relative to the work you’ve done, and how you’ve sort of created a mental framework that people can utilize… So you actually went ahead and took all of this and wrote a fabulous book, right?

Two books.

Two books, that’s right. What’s the first one?

The first one, my baby, the one that took the most amount of time to write, is called “Are you a monster or a rock start? A guide to energy drinks.” And this one is available as an audiobook, which I recommend, because I got a comedian to read it, so it’s way better. All of my dad jokes and my puns - he does a way better job of selling than me. So that’s the first book, and that’s more about the ingredients in energy drinks. Everything from B vitamins to yerba mate.

The second one is more about productivity and fatigue, and it’s called “How to get shtuff done when you feel like poop.” Essentially, paraphrasing, without the swear words. [laughs]

When things hit the fan, this is what you read.

Which I like, because you’re talking to people who are in fatiguing environments, generally using caffeine to get amped up, and you’re kind of maintaining the ability to be productive while being fatigued, or how to navigate all of those scenarios.

Exactly. Because the first book is more about like “Alright, can you eat this? Is this safe?” The second book is more like “Alright, I’m exhausted. What do I eat?” It’s not so much about safety as about “How do I get through this day, because I’ve had three hours of sleep for the last three days.”

Right?! And we talk about this a lot relative to – I mean, a lot of people in tech, when they’re using their brain, and you don’t think about the way in which your brain is using energy, and then when you start off tired and the cognitive load… Sometimes it’s like by noon, or ten…

The stereotype is stay up all night, drink Red Bulls, drink Mountain Dew, drink Cokes, or be at the office fridge-full of X, whatever X might be… It could be Bang, I don’t know…

Everybody is hanging out in the coffee room…

Yeah, the stereotype is massive amounts of coffee; fuel them - and “fuel them” being the troops, the people doing the work - with caffeine, essentially… And then obviously, learning from this conversation, in many cases it’s really the sidecars, the sugars, the creatines, the other things that have these negative effects. So that’s the stereotype, “Fuel them with these energy things, and they will just go.” But at some point, that “Just go” ends, and people crash. And usually, at least a burnout, fatigue, or just straight up done.

Absolutely. I mean, if you think about it this way - and this is kind of the thesis of my second book - even people who’ve had a full night’s sleep or all the caffeine they could possibly want can still feel mentally overwhelmed or physically exhausted.

Right. So it doesn’t necessarily mean you need caffeine if you’re tired, but maybe caffeine will help you when you are.

Yes. It’s knowing how much caffeine to have, at what point, and at what point to try other things.

So you created a sort of pyramid relative to caffeine consumption, to help people go “Well, what stage am I at?”

Can you tell our listeners more about that?

I would love to. This is called “The five levels of fatigue”, and it’s a pyramid with level zero at the bottom of the pyramid, and level five at the tippy-tippy-top. The reason I made it a pyramid is because if you think about the X axis, that is your productivity. So the base of the pyramid is very wide. That’s how alert and engaged and excited you feel about life. And as you get up to the tippy-top, the X axis, the tippy-top of the pyramid is very small. That’s because when you get all the way to fatigue level five of five, your productivity is very low.

[56:29] So with each level of fatigue there’s different symptoms you might feel. For example, fatigue level one is commonly associated with dehydration and drowsiness. So if you’re doing something that’s boring and repetitive, or if you’re doing something that you haven’t had enough water recently, you can feel tired, but caffeine is not the solution. You might need water, you might need to get up, you might need to take a little break and change what you’re doing. Caffeine is not the solution for fatigue level one, because your fatigue is coming from boredom and dehydration.

At fatigue level two you’re feeling more tired, and you might need some caffeine, but not a lot of it. You feel a little distracted, you feel a little lethargic, so you just need a little bit of caffeine, or you need someone to make you laugh. You might need something to boost that dopamine in other ways than caffeine.

The next level up from that is when you’re really stressed out and struggling. That’s fatigue level three. So you need more caffeine at this point, and I’ve got different recommendations in the book… But at fatigue level three, because that level is also associated with stress, there’s other things you can do to reduce your stress. At fatigue level three, because that level is associated with stress, one of the things that you can do is just to get started. Sometimes we have this stress because we’ve got 20 million things on our to-do list; but if you just get started, sometimes that momentum can carry you through and you feel less stressed because you’re actually moving forward, you’re actually doing something.

Level four is when you’re exhausted. At this point, you have the strongest amount of caffeine that you can, you have 400 milligrams, which is all you’re allowed to have in a day, and you need to start easing up, you need to start delegating. You need to start admitting that you’re in an energy emergency, and you won’t be able to do everything you plan. You need to be comfortable with letting someone down, because it’s like that point in the airplane before you crash; you need to put your mask on before you help someone else, right? Fatigue level four is that point - you need to help yourself, because you can’t pour from an empty cup.

And fatigue level five of five is zombieville. There is no amount of caffeine that will help you at fatigue level five, so you just need z’s, you just need sleep.

You just need to go to sleep, right?

So this is helpful in terms of recognizing – because I don’t know how many people do a sort of assessment or self-reflection around how they’re feeling, unless they’re focused on it. We talked about – you know, we feed whatever we focus on… And then I think – even in changing habits, recognizing “Oh my goodness, at 2:30 every day is when I go to the snack machine”, or that’s when I’m like “Give me my latte…” To have this sort of template to go “maybe I’m really just, you know, tired, or I’m a little stressed, because the end of the day is coming. I really wanna clock out and check out, but I can’t yet, and so what other tools or options are available to me instead of what I’ve always done?”

Absolutely. You said it perfectly, because like you said, you feed what you focus on, and mindfulness is such a huge point of this. Even if you did nothing else other than taking a second to assess how tired you are, that awareness has huge payoffs. So even if nothing else comes from it, if you don’t do any of those actions, in terms of finding a chance to walk around, get a drink of water - even if you do nothing else other than saying “Hm, I’m at fatigue level three right now”, that mindfulness can sometimes help you realize where you are, and it can help you take a pause point before you decide your next steps.

If you were on a bridge, and you can only go two directions, you can’t go four directions. So this is keying off your mindfulness - you can’t go certain directions, so knowing where you’re at in terms of this pyramid, for example… Knowing where you’re at, this mindfulness, is gonna give you an indication of what to do.

Yes, absolutely.

And so often do we just not be grounded and think “Okay, where am I at? What am I feeling? Why am I feeling this way? How do I get to where I’m trying to actually go, versus just keep running that durable wheel thing?” You just never to where you’re trying to go because all directions are no direction.

Work smarter, not harder.

Right?! I love this. We posed this question to our community over in Slack about how they’ve used caffeine, and I loved it because somebody said “I used to use coffee for its utility, i.e. focus and keeping me awake, but then I ended up having to quit it cold turkey for a year.” And they said “I replaced the ‘keeping me awake’ utility by actually going to bed earlier.”

[laughs] Yes, if you can, then sleep is a great alternative to more caffeine.

I think we all have different indicator lights, but recognizing what these are when they emerge, so that you can learn to do differently… Because it’s sort of like “I need to actually be more thoughtful”, instead of that habit loop (I say [unintelligible 01:01:52.03]) there needs to be that hiccup to go “Oh, wait a second… Every time I’m tired, I go reach for a coffee. Maybe I don’t really need it, or I just really like it.”

So for the consumer who goes “Well, I really just enjoy coffee” or “I enjoy my energy drinks”, how do I have it while managing the caffeine intake associated with it? Do I mix it up, because I just like the taste or the flavor or the contents, or do I just exercise self-restraint?

Well, what I like to do is I mix it up all the time, but then I also take multiple days to finish an energy drink. So if I like the taste, but I don’t need the whole container’s worth of caffeine, then I’ll have a few sips, I’ll get my dopamine boost, I’ll get my reward triggered, and then I’ll put the rest of it in the refrigerator and I’ll have that the next day.

So that’s a good way to get some of the benefits, the mental benefits, without having too much caffeine.


Moderation, and also being strategic. If I’m this tired, I know I need this drink; if I’m this tired, I know I need a weaker drink. It’s a proportionate response.

But I think there can also be a lot of play involved in that, and fun, to be like “Hm, let me go and be my own scientist and figure out what works” using these sort of levels, and go “Did I like that? Would I try again?”

Part of how you’ve done some of the research is not only the science behind it, but you’ve tried these, haven’t you? Many of the energy drinks.

Oh, yes. Yeah, I’ve researched the labels, but then I also tried them myself. Then I do some diligence in terms of the companies. If it’s somebody that just mails me an energy drink, I’m very cautious about “Okay, who’s making this? How much can I trust them based on their website or the quality of their marketing materials?” So I’m testing them in all different aspects, not just tasting them and not just reading about them, but all levels of research going on.

[01:03:59.27] So can we shift gears and do a little quiz, true or false, fact or fiction? What do you think?

Yes, I would love that.

Okay. So we’ve sort of talked about these, but I just think it would be a fun little blast… And feel free to pull in research or tell us how we can better understand these. So true or false - caffeine is not safe.

False. It’s not safe if you have more than 400 milligrams in a day.

Awesome. And then is there also a little caveat relative to if people have heart conditions?

Yes. If you are sensitive to caffeine, whether or not you’re pregnant, whether or not you’re a child or an adolescent, whether or not you’ve got heart issues, you want to be your own scientist. You want to be very careful about how much caffeine you have. But for the average population, caffeine is supposed to be safe in moderation, and that moderation is that 400 milligrams per day.

Okay. True or false - caffeine is addicting.

I’m gonna say – oh gosh, this is a hard one… I’m gonna say true because of its addiction in different ways. Not the neurochemical ways, but addicting in that it’s like comfort food. You become attached to it the same way as – I’m addicted to a certain song during stressful days. It’s addicting in that way.

Okay, so true or false - consuming caffeine can cause heart problems.

False. Did you know that 300 milligrams or less can actually reduce your risk of heart arrhythmia?

No. So arrhythmia is disregulation in the heartbeat, right?

Yes. And actually, caffeine can help your heart, as long as you stay under 300 milligrams.

So what about those wonky stories, or sort of newscasts we hear about this person – like you mentioned earlier, they ended up in the hospital, or had a heart attack because of an energy drink they consumed.

Every story that I’ve ever read, every story that’s ever been mailed to me about someone being hospitalized or dying because of caffeine - they had way more caffeine than they were supposed to… Not just more than this 400 milligrams, we’re talking like 25 Red Bulls in a day. Yes, the last one - there was a man in the U.K. that survived, but he was hospitalized. He had 25 Red Bulls in a day. And his conclusion from that is these things shouldn’t be sold to children. But he’s not a child – even if he got his wish, he would still have gotten sick from having 25 Red Bulls in a day. So that conclusion of his illness was not logical to me.

But yes, people that have hospitalizations or die from caffeine - I think there may be one or two that has a genetic predisposition, but everyone that I have seen personally, and everyone that I’ve ever researched and followed up on has had way more caffeine than you’re supposed to have in a day.

Yeah, so I always think about this, and I don’t know unless you studied it - recognizing the difference between causing something or something is correlated.

Yes, I’m so glad you mentioned that.

Because that’s what people think. “Well, the energy drinks are to blame. They caused it.” And it’s like, it’s never that simple.

Exactly, exactly.

So it’s not a direct causation, but it doesn’t mean if you’re outside the normal limits, or there’s these other predispositions because of your genetics that it can’t create a really poor storm and outcome.

Yes, exactly. And the best example of that is caffeine and alcohol. I’m sorry, was that one of your next questions? [laughs]

No, I was gonna say – yes, right, but keep going.

We haven’t talked about that one… We talked about sugar and other sidecars, not alcohol, like Red Bull and vodka…

I don’t know – I think a lot of people, or it’s been marketed often as a Red Bull and vodka. These go together.

So yeah, can they go together? Is alcohol okay with caffeine or energy drinks?

[01:08:07.22] No. Do not mix your uppers and downers. The problem with mixing caffeine and alcohol is 1) it takes the fun out of alcohol. I can’t speak for everyone, but I drink alcohol to feel dizzy, like “Wooh! This is fun!” But if you have caffeine, you don’t feel that, which - that’s the whole point.

And that’s the problem - you don’t feel drunk. So you feel like you can get into a car, you feel like you’re making good judgments, trusting this person you’ve just met…

Oh my gosh, yes…

You feel like you can have 3, 4, 5 more shots, because you don’t feel drunk. But you are. So the people that have been hospitalized from energy drinks - it’s the correlation/causation thing. Are they hospitalized because of energy drinks? Are people that have energy drinks more likely to be in these dangerous situations and be in the hospital?

Yeah… Because one, alcohol makes you feel like you can do anything, to some degree. Like you can make choices that you wouldn’t normally make, and they’re safe; that’s what I mean by that. And then the caffeine gives you the energy to do so. So normally, alcohol alone gives you the ability to make those choices, but usually subdues you, because you’re like “I’m kind of too tired to do it.”

But the caffeine is like “No, no, you’ve got the energy. Just go jump. Just go do. Just go drive.”

Yeah, “Go jump off the cliff. It’s a great idea.”

“Yeah, this is a great thing to do.” So you’re even more dangerous.

It’s just cringeworthy to me. It makes me shudder on the inside. Wasn’t that one of the things you wrote or have talked about on other occasions was I think actually for a college student out of somewhere here in Washington? Is that right?

Yes, so in 2009 there was a student from Central Washington University that was hospitalized with a blood alcohol content of 0.35…

0.35. 0.30 is lethal, so they were above that… And the reason they were above that is because they had this drink, which thankfully is no longer around in its original formula, Four Loko, a.k.a. “blackout in a can”.

Oh, yes. I heard about it.

So the problem with Four Loko is it was giving you way too much alcohol, and way too much caffeine, all in one nice little package. So people that would have one can had enough alcohol to black out… But that’s the problem - when you just have alcohol, your body has this safety mechanism where it says “Okay, go to sleep. You’re done. Just stop.” When you have caffeine, it overrides that safety mechanism, so you can stay awake and keep causing chaos, internally and externally.

So that’s what happens to these college students, and specifically this one that was admitted to the hospital, that kind of shed the light on the dangers of Four Loko, that had been happening for at least a year before this incident at Central Washington University.

Oh, that’s just so terrifying… I think education and teaching people, and especially when consuming alcohol, when your frontal lobe doesn’t work the same way, right? As a result, to be able to go “How do we learn to make wise choices, and enjoy our lives, but still have guard rails?” This is why on freeways and cliffs there legitimately, literally are guard rails - to keep us on path if anything goes awry.

That’s right.

And so one last… Going back to our quiz then - consuming caffeine leads to dehydration. True or false?

[01:11:52.03] Surprisingly. Caffeine’s diuretic effect is very weak, meaning caffeine will only make you have to pee if one of three things is true. One, if you have more than three cups of coffee, more than 250 milligrams of caffeine; then it will make yo have to pee. Two, if you’ve had enough liquid. For example, if you drink 24 ounces of liquid, you’ll have to pee, whether or not it has caffeine in it. And then the third thing, if you’re not a regular caffeine consumer, if this is the first time in a while, or the first time ever that you’ve had caffeine, then it’s more likely to trigger your kidneys to make you feel like you have to pee.

Otherwise, if it’s not a lot of liquid, if it’s not a lot of caffeine, and if it’s not your first time having caffeine, you won’t have to pee. It won’t make you dehydrated.

See, I think that is one of the most common misconceptions, right? Don’t you agree?

Yes, it’s very common.

Well, they say it’s a “natural diuretic”, which is true, but to a certain degree, based on what you’re saying.

So it is a diuretic…

It’s like saying chemicals are poison. Everything is poison at the wrong dose. Too much water can kill you, because you can drown…

So if you have a normal dose… If you have as much caffeine as you’re supposed to, you’re fine.

So how does it work, and why is it that many people often have to not just go number one, but number two? Because I think this is really interesting, and I want our listeners to–

Come on… [laughter]

Oh, no…!

We’re going there!

We’re going there… As we should. It’s important. It’s a regular question that I get. I can’t speak to number two as well, because that has more to do with the chemicals that are in coffee. I think there’s caffeic acid and some other anti-oxidants and nutrients in coffee, that kind of trigger that impulse to go number two. But with number one, a lot of times the drinks that people are having are workout supplements, or they’re having large cups of coffee that have a large enough amount of caffeine to trigger that response in the kidneys.

It has to do with your glomerular filtration rate, so it doesn’t change the amount of water your body is producing, but it changes how salty that water is. And so because it’s more concentrated, the water that’s in your kidney feels more salty and feels more concentrated, you have a greater desire to pee because of that high concentration. So that’s what’s happening.

So is there anything – because something I read was more relative to the way in which it relaxes your muscles, hence why you would be more prone… It seems counter-intuitive to some degree, that caffeine is a stimulant, but it actually relaxes the muscles of your intestines, which makes you go.

That makes sense. I feel like that’s one of those things that’s a good theory, but like how do you measure it in a research setting? Because yeah, that makes sense; caffeine is a vasodilator, it widens your blood vessels, so that totally makes sense.

So one of the things I want to – because you know, I’m gonna take a hard left now…

…and talk about caffeine relative to mental health.

Oh, yes.

Because this is something really important for our listeners to understand. In my line of work I see oftentimes people struggle with – they already are coming to me for one issue or another… But in the case of anxiety, that caffeine can be a sort of mixed bag, and potentially not helpful when it comes to anxiety. It’s a stimulant, so the jitters that you were talking about from caffeine consumption amplify that experience.

I’m glad you asked about that, because I have in my notebook here five different research papers that I was looking at before this, that I wanted to talk about… But the one that’s most applicable, and I think the strongest one in terms of evidence - are you familiar with POMS, the profile of mood states?

[01:16:15.17] Yeah. So the paper that I love the most, and the paper that I’m gonna refer to now, is a systematic review that was done in 2017, that looked at the safety of caffeine across all ages and all demographics. It’s a very, very comprehensive study; it’s like 36 pages. But one of the things that they looked at was caffeine and your profile of mood state. So caffeine and anxiety, caffeine and depression etc.

They’ve found that caffeine only increases your anxiety when you have larger doses than your one day’s amount. There were six different studies that looked at whether or not caffeine gave people more anxiety, and the only studies that did find that association were the studies that used caffeine in large doses. All the other ones, if they used caffeine in small doses, no correlation with anxiety.

So you’re talking large doses, like over 200-250 milligrams?

Yes. For sure, when you get over 400. But if you go over 200-250, then yes, there’s a greater risk.

Even in a single dose too, right?

Mireille was sad to hear that I sold my espresso machine. She’s like why did you do that? [laughter] Well, I was my own scientist, and I determined that when I drink espresso, when I make even an Americano, which is generally just a shot or a double-shot of espresso, plus the rest is water essentially - or even like any sugars, or monk fruit, or stevia; just simply that - I would be off to the races. And if I had two, it was clear that I had two. One was enough, but two – I realized that that brew method just must have had… I didn’t measure it; I could determine based on how I felt, that it had more for sure caffeine in it. My assumption now, based on you saying this, is that it definitely had more than 200 milligrams of caffeine… Because I could tell for sure, just on one cup.

And a regular cup of coffee - you’d be fine.

Right. Like, if I’d do a French press, or I’d do pour-overs, aeropress - I’ve got a couple of different brew methods that I’d prefer. Espresso was fun. My son would help me make the coffee. He loved to tamp it with me. We would grind the beans… It was a fun thing we did in the morning, so he would help me make my coffee. He loves that. He still helps me, but just now it’s not with the espresso machine, now it’s just with pour-over, or French press, and none of those methods ever made me feel - even if I had three cups - like I was gonna burst through the walls… Whereas my espresso machine - I loved it, I loved the coffee from it, but not the feeling I got by drinking it.

So with that, again, going back to our Slack community, somebody else commented - and I wonder if you could shed some light on this, Danielle - relative to… They said sometimes they have an espresso and it wakes them up, but other times they have an espresso and it just puts them to sleep.

That’s tricky… So my gut instinct in that scenario would be that they’re either fatigue level five in those situations, and maybe the espresso isn’t working because they’re already mentally exhausted, or physically exhausted, so the caffeine isn’t capable of waking you up physically. And even the placebo effect of like “Yay, this is my espresso” might not even be working…

But I’ve also met people that have cups of coffee right before they go to bed, and they’re fine. Usually, those people have a consistent effect. It’s not - it affects them good one way, and it affects them a different way on a different day. So usually it’s consistent. So my gut instinct would be that if you are getting a different effect between different days, it’s because some days you’re just more drained, more exhausted.

[01:20:07.08] So with that then too, we also asked about relative to Covid, because lots of things have changed for people with the Covid lifestyle… So the coffee intake increasing during Covid, which - I don’t know, I might think about it being relative to a number of different things, like being 1) I want more comfort amidst the stress and strain, but 2) just more access. Less distance to walk, or sort of it’s more easily accessible… But you know, what might you say to that person who’s going “Well, it’s probably doubled” or “I’m taking in way more coffee now that my work situation has changed”?

Yes, I have seen this across all different industries, from first-responders that are being shipped cases of caffeine products to their hospital, as well as the parents that now have to manage a job, and their child, and their pet, or whatever else they were managing before… So caffeine intake has increased for everyone throughout this Covid crisis, and I think we’re going to be seeing some effects of that in maybe five years… For example, how many products come out in the next 3-5 years with even higher amounts of caffeine? How close are we gonna get to that dangerous amount of “Your whole days’ worth of caffeine in one teeny little can”, because people have built up their tolerance of caffeine during the Covid crisis.

So that was the other thing… I was surprised, because – I think most of us know that there’s caffeine in chocolate, but there’s other foods that have caffeine in it as well, and that according to what I’ve found, the FDA (here in the U.S.) they don’t actually have to label it unless they’re adding more caffeine… Right?

Yes, yes.

So to some degree you can’t wholly know with some of the foods, but can you tell our listeners - what other common foods that people eat might have caffeine in it?

Honestly, unless it’s a food that has added caffeine, you don’t have to worry about any other foods other than chocolate. I think dark chocolate and aspirin are the most common objects that people don’t think about as caffeinated, that do have caffeine in them.

How much caffeine is typically in Aspirin? Like Excedrin, Tylenol…

I think it’s 45 milligrams… I would recommend double-checking this on Caffeine Informer. Again, this is like my bible; Caffeine Informer has all the answers. But yeah, it’s not small. It’s like 45 milligrams in Excedrin Max, [unintelligible 01:22:57.06] And then with chocolate, I think one full dark chocolate Hershey’s bar has a bit lower than that. I wanna say it’s around 30 mg. So like a cup of tea.

So if you’re eating one of those a day, and three coffees(ish), check yourself… Right?

Otherwise - maybe cool.

But there’s more and more food now that comes out with added caffeine. There’s a cookie that I like, a protein cookie from Beast Cookie Company, that has 160 mg. So a cup of coffee and a half; one and a half cups of coffee into this cookie. But it’s this large protein cookie, with 10 grams of protein and not that many grams of sugar. So that’s kind of what I’m seeing increase more in the marketplace in terms of foods that your listeners might need to be aware of. It’s becoming more trendy to add caffeine into foods where it wouldn’t normally be, so like protein bars and cookies.

And what’s driving the trend? Is productivity driving the trend, or is it – you say consumers create the habits, because you mentioned before, what you desire to put in in terms of caffeine wasn’t what the consumer wanted, so… Somebody’s wanting a cookie that makes them more alert.

[01:24:18.14] People want caffeine, they want alternatives to the scary, stereotypical energy drink… So other product developers are saying “Hey, what if I could give you this healthy cereal bar with your cup of coffee’s worth of caffeine in here?”

Yeah. Then you can just drink some water and have this cookie that’s mostly healthy [unintelligible 01:24:36.24] versus the cup of coffee. So it’s just changed. It’s moving things around a bit.

I like that. That’s good though. I think we need alternatives, because not everybody wants the cup of coffee. As you said before, you drank energy drinks; that was your saving grace. Rather than actual coffee.

And that’s what you’re gonna see other people do, like “I would prefer to eat a bar, or eat a cookie, or something like that, versus drink this nasty drink… Or go through this five-minute process to make French press at home. I don’t want that.” They want alternatives.

So Mireille, going back to your point - this is what I’m seeing a huge spike in because of Covid; all of these companies that were kind of unknown before are like “Hey, look at us, we’ve donated all these coffees, or all these chocolates, or all these cookies with caffeine to these hospitals”, and they’re getting that brand recognition, and they’re probably attracting a lot more customers because they’re providing this caffeinated product (not always a liquid) to people in desperate need of caffeine, to get them through their extra-long, extra-stressful hours during this pandemic.

Yeah. And I think that’s so hard, because I know just when we’re tired too we make different decisions than when we’re alert.


What was the acronym you mentioned before, Mireille, about “Are you hungry, tired…?”

HALT, yeah.

Hungry, angry, lonely or tired.

Hungry, angry, lonely, tired. I’ve gotta memorize it. I’ve systematically improved my life because of HALT.

Yeah, but it’s really getting at energy… Recognizing that energy is always in flux. Emotions are energy. I think of ways in which people are taxed emotionally feels more like when you wake up the next day, you feel like you were hit by a Mack truck, except you don’t remember it… Right? But it’s this totally different experience of fatigue.

We talk so often with our listeners about the value of “Name it to tame it”, and that building this repertoire of vocabulary helps us to navigate our lives differently… So hopefully even in this people can recognize and have different words around their state of energy, to then make different choices in that regard.

Absolutely. I mean, if you take that three seconds to assess “Alright, I’m at fatigue level 3. Maybe I should pause before I say things out loud, because I’m gonna say something I regret. I’m more likely to say something I regret right now, because I know I’m at fatigue level 3.”

[01:27:09.07] Sure. I think that in general people are getting there faster because of the load just with multiple demands, and the rate of change.

There is so much accommodating, and it’s like Garmin, “Recalculating… Recalculating…” And that’s gonna deplete our energy stores. So if you know that, then you can be like “Okay, I literally just need to take a nap for 15 minutes. Or let me go move a little bit, do some walking.”

I find it somewhat humorous in looking at my stats too, my movement level or walking that I used to do in months previous… And while I would like to improve that, life right now is not facilitating that in the way that I want.

You have to be very purposeful now for your movement, whereas before it sort of came natural, because we were moving around a lot more.

Yeah. Danielle, can I ask - where can people find you? Where can people get access, and tell us what can you offer to our listeners.

So I love speaking in front of groups, and that slowed down a little bit, because people obviously aren’t meeting in person… But I still love doing Zoom calls, and I do a lot of conferences and workshops, helping people address their caffeine questions, as well as the different levels of fatigue. So one of the things I offer is a caffeine and fatigue workshop. You can find all of the details about that at There you can find all the details about the different speaking and the different workshops that I do.

Other than that, I love being on Instagram. I find the people on Instagram are very engaging, and I get to speak to a lot of first-responders and nurses on Instagram, and I love talking to that group. So I would say find me on Instagram. I’m @greeneyedguide.

And the third thing I will say - my website is, which is where you can learn more about my books, and there’s a lot more information on there about different energy drinks I’ve reviewed. So you can find a lot of content about popular energy drinks, ingredients and safety on


We are so thankful for you coming on and talking to our listeners. So if you could give our listeners one quick takeaway to how they can navigate caffeine differently, or a question they can ask themselves, what would you leave them with?

I would say always, always, always read your labels. Always nurse your caffeine, and always ask yourself “Do I really need caffeine, or can I take a break, can I do something else to help my mind and my energy right now?”

And there you have it. Danielle Rath, thank you, thank you, thank you.


Our transcripts are open source on GitHub. Improvements are welcome. 💚

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