Nutrition Bites

Caffeine Craze - How Much Is Too Much?

September 09, 2021 Maggie Clark Season 1 Episode 15
Nutrition Bites
Caffeine Craze - How Much Is Too Much?
Show Notes Transcript

Caffeine is the world’s most popular drug - the majority of the global population consumes it every day!  As a stimulant to the nervous system it can have some pretty astonishing effects on our body like increased alertness and energy.  Now, thanks to  the skyrocketing popularity of added sources of caffeine, such as energy drinks and pre-workout supplements, consuming high amounts of caffeine is easier than ever. But those high doses can come with some pretty terrible effects, like seizures or even death. So how much is too much? Tune into Episode 15 to find out more. 

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Credit to MonoSheep for the theme music.

Welcome to Nutrition Bites. The no nonsense podcast where you get the truth about food so you can eat what you want and be healthy. I’m your host Maggie and welcome to Episode 15 of this series! Autumn is in full swing which means the days are getting darker and I am in desperate need of an extra kick during the morning. The solution to my fall fatigue is a bonus cup of coffee - which got me thinking. How much do we really know about that energizing little molecule found in our daily brew? And how does it affect our health? On the menu today, caffeine. 

In my high school, going on a Starbucks run was like a right of passage because...drinking coffee was ~cool~. Despite how babyfaced we looked, holding a branded cup as you entered class was like an instant symbol of adulthood. And if double cream and triple sugar coffee wasn’t your thing you could still prove your maturity by crushing a can of Monster energy drink in the parking lot during lunch. Teenagers are weird. In university caffeine was a staple during morning lectures and also late night escapes in the form of Vodka Redbulls and Jaggerbombs. In the workplace, coffee breaks have become a cherished ritual, less for the drink and more for the hot gossip. Caffeine has even found its way into the fitness world, in the form of pre-workout supplements - another marketing success for gym-bro companies. Safe to say that throughout our lives and routines, caffeine is all around us - and we freaking love it. It is the world’s most popular drug - over 80% of North American adults consume caffeine every day and countries in Northern Europe hold the record for highest coffee consumption per capita. But for something so widely ingested, we don’t talk about its effects enough. So let’s dig in.

Caffeine is a psychoactive drug, which puts it in the same family as alcohol, marijuana, cocaine, heroin, and LSD. Off to a fun start aren’t we? Psychoactive drugs are substances that alter your perception, mood, and cognition by affecting the nervous system. Caffeine works to speed up the central nervous system, which consists of the brain and spinal cord. On a deeper physiological level, the caffeine molecule works by temporarily blocking the effects of a neurotransmitter called adenosine. Neurotransmitters are chemicals in the body that cause reactions by binding to receptors on cells in the nervous system. Each neurotransmitter is uniquely shaped to fit into a particular receptor, just like how you have keys that are made to fit into a specific lock. When adenosine binds to its receptor, it’s effect is to slow down the nervous system, making the body feel relaxed and sleepy. Caffeine has a similar shape to adenosine, almost like an identical key, so it can fit into the same receptor, or lock, and block adenosine from binding. This means those sleepy and relaxed feelings are temporarily blocked. Pretty sneaky huh? Caffeine affects another neurotransmitter called dopamine - also known as the feel good chemical. In a similar, but less intense, mechanism as heroin, caffeine maintains elevated levels of dopamine in our system, which keeps us feeling good for longer. This also acts to fuel our desire for another hit. Caffeine also triggers the release of adrenaline - a hormone that makes us feel awake and alert. So no wonder we love this drug - by blocking adenosine we feel less sleepy, by increasing dopamine we feel good, and by boosting adrenaline we feel energized. And one the best parts is that we can begin to feel these effects within minutes. Talk about bang for your buck! After about 45 minutes your blood will contain the max concentration of caffeine, and slowly decrease from there on out. It’s half-life, which is a term used to describe the amount of time it takes for a quantity to be reduced by half, is about 5 hours. So if you drink a cup of tea at 8 a.m, half the amount of caffeine will still be in your system by 1 in the afternoon. Generally speaking, it takes your body roughly 9 hours to clear all the caffeine out of your system - so if you want a good night’s sleep, keep your brew to the morning.

Now I realize that all this talk about neurotransmitters, blood concentration and half-life makes caffeine sound like something that should be prescribed by a doctor. But caffeine has been widely studied, and moderate amounts will rarely harm a healthy adult. But what does “moderate” mean exactly?

Up to 400 mg per day is the moderate amount of caffeine for a healthy adult. To put that into more practical terms, that’s about 3 - 4 cups of coffee. Depending on the bean and type of brew a cup contains around 100 mg. And when I say cup I mean a real 237 mL cup not a Starbucks venti. Those are insane. Other popular sources of caffeine include tea and pop. A cup of black tea or can of diet coke contains about half the amount of caffeine as a cup of coffee, and a mug of green tea or can of regular coke is even less - around 30 mg. Caffeine also naturally occurs in cocoa beans - which means that chocolate, in particular dark chocolate, is a natural source. A standard 100 gram bar of dark chocolate, which is the size of a Lindt bar, usually contains around 80 mg of caffeine. And because milk chocolate contains less cocoa beans, it will have significantly less caffeine - around 20 mg. So to reach this moderate caffeine limit of 400 mg you would have to drink 3-4 cups of coffee, 8 cups of black tea, 13 cans of regular coke, or 5 bars of dark chocolate. Unless you’re at a speed-drinking tea ceremony, or on a tour of the Wonka factory, that’s a lot to take in. But there are also plenty of sources of added caffeine that make reaching that 400 mg limit a lot easier.

Energy drinks are a popular beverage amongst teenage boys who want to seem hardcore, and also chronically fatigued milennials and night shift workers. Your average tall can of Monster Energy or Rockstar contains around 160 mg of caffeine - about 1 and a half cups of coffee. And the smaller redbull can sit at around 80 mg. But there are so many varieties of these drinks, many with ridiculous names like Thermo Neon Blast or Punch Monster Khaotic (chaotic spelled with a K obviously), and the caffeine content varies widely - with some drinks containing up to 250 mg per can. And those 5-hour energy shots that they sell at gas stations also pack a mean punch for their size with each tiny bottle containing a 200 mg dose. 

Added caffeine has also infiltrated the health and wellness world. Many pre-workout powders or I-don’t-have-time-to-eat-my-veggie “greens” supplements contain caffeine - especially if they are labelled with words like “energy” or “boost”. Caffeine also comes in pills, gummies, gels and chewing gums - most often marketed towards athletes but also used by stressed out students like Jessie from Saved By The Bell. The quantity of these supplements can range from a low dose of 20 mg to extremely high doses of over 400, which makes these products an easy route for overconsumption. And what exactly happens if you do go beyond that “moderate intake” level?

Fortunately, for most healthy adults, going slightly beyond 400 mg results in more of an unpleasant experience rather than a deadly choice. Think upset stomach, fast heart rate, shaky hands, and headache. But larger doses, especially by people who don’t normally consume caffeine, can cause convulsions, elevated heart beat, and even delirium. Toxic effects, like seizures, can occur at around 1200 mg of caffeine, and death at over 5000. Now those ranges are extremely difficult to hit when consuming natural sources of caffeine, but it can be a much easier mistake for those who consume added sources. Just this past year a UK personal trainer died after drinking a mislabelled pre-workout beverage that contained 200x the safe level of caffeine. And dozens of teenage and young adults have also died from energy drinks, mostly because the high caffeine worsened previously undetected heart problems. Because of the increasing popularity, and known risks of these beverages in youth, the UK recently banned sales of energy drinks to anyone under the age of 16. 

Considering how often we consume caffeine, death by this drug is still extremely rare. But there are plenty of negative effects that I’m sure you are familiar with. The 5 hour half-life of caffeine I mentioned earlier makes it a well known sleep disturber. And while it doesn’t cause anxiety, caffeine absolutely worsens symptoms. That’s because it stimulates the “fight or flight” response in your body and this can heighten an anxious reaction. High caffeine consumption can also increase the risk of miscarriage during pregnancy, and lower the birth rate of a baby. This molecule also slightly reduces calcium absorption - which can be a problem for post-menopausal women or others at risk for osteoporosis. And remember, caffeine is a drug, which means that we can become dependent on it and experience withdrawal if we stop our daily dose. Symptoms like irritability, headache, depression and fatigue are all common for the first few days after we stop, but fortunately don’t last very long. Considering all of this, it makes you wonder why they focused our anti-drug education on crack cocaine and not caffeine. 

And maybe the reason is, that despite the negative effects that caffeine can have, consuming moderate amounts does come with some benefits. Otherwise...what the hell are we doing drinking coffee and tea every day? As I’m sure many of you have experienced, caffeine assists with cognitive performance - fancy words for making our brain work good ya know? It’s been proven to help us stay awake and alert, and improve our attention and reaction time, especially when tired. But while it does keep us “on task” so to speak, caffeine does not help with judgement or decision making. So while a morning tea can help you be alert enough for your drive to work or important business presentation, it won’t necessarily reduce your risk of a fender bender or Freudian slip. The real solution for that is more sleep, but that’s a much harder nut to crack. 

Now for those pro athletes, or those who play rec sports but think they’re pro athletes out there, caffeine is known as a safe and recommended aide to help improve athletic performance. The International Society of Sports Nutrition states that athletes who perform endurance activities, things like distance running, cycling or swimming, benefit the most from caffeine - especially when it’s ingested about an hour before exercise. The optimal dose is based on body weight and tolerance, but for a 150 lb, or 70 kg person, a caffeine hit between 200 and 400 mg is ideal. Many pro athletes use energy gels or caffeine chewing gum to get their pre-performance dose, but the more popular exercise aid is the pre-workout supplement. As if taking something after your workout wasn’t enough. But despite my cheekiness, I must say, the effects of a pre-workout caffeine, whether from a supplement or espresso, is enticing. Not only do you experience a boost of energy, caffeine also helps reduce the perception of fatigue, effort and exhaustion. In other words, you can perform a chest press for longer and more intensely before feeling the need to abruptly stop and loudly drop the weights with an exasperated grunt. While this sounds like a pretty ideal addition to your gym routine, you should be extremely careful with any supplement you buy. This industry is not well regulated, and so the caffeine content in these pre-workout powders, beverages and chews, can be well above that “moderate” intake level. This is also true for those “green powders” that are becoming a popular add-on in people’s diets. Because the regulations for these products are so poor, companies don’t have to label the caffeine clearly - making it difficult for you to know how much you are actually taking in. You often have to look under medicinal ingredients for the content and source of caffeine, which is usually listed as green tea or matcha extract. Don’t be fooled by the natural sounding name - it’s just caffeine disguised as a holistic-sounding phrase. 

When talking about caffeine overall, an important thing to consider is your own individual sensitivity. Some people get jittery after 1 cup of green tea, while others proudly own “coffee addict” paraphernalia. Factors such as age, weight, sex, and genetics all impact how much and how quickly caffeine affects you. So that 400 mg “moderate intake” level I spoke of earlier, may be far too much for your system. Even what you eat right before ingesting caffeine can be important. Food and fibre slow down the absorption of caffeine, which means you’ll feel the effects faster if you consume it on an empty stomach. Smoking cigarettes speeds up the breakdown of caffeine, so the effects don’t last as long, while pregnancy and oral contraceptives, like the birth control pill, slow down this process. Your caffeine tolerance is another impactful detail. Just like with many drugs, regular intake can increase your tolerance, making it more difficult to feel the effects unless a higher amount is consumed. A twisted game where one cup of coffee quickly becomes two..until it becomes three..and then all of a sudden you’ve bought a $500 espresso maker and can’t recall what water tastes like. The best way to beat this dependency is to not consume caffeine every day, but easier said than done when a coffee shop can be found in quite literally every neighbourhood. 

Regular consumption of caffeine is a shared global experience - it provides comfort in unfamiliar places, a way to connect with friends,and helps keep us awake during trying times. And for all intents and purposes, it’s not something to be particularly worried about if you are consuming a few cups of coffee or tea every day. Where you really need to be mindful is with added sources of caffeine, like energy drinks and exercise supplements. Because while being wired may feel exciting in the moment, moderation will always feel better in the long run.

That’s been the bite for today. Stay hungry.