It’s well known that caffeine gives us a boost, and it does this by acting as a trigger on our adrenal glands, the organs which manage our stress response. But how you personally use caffeine in your day is nuanced based on how your body responds to caffeine and in what general state your body is in the moment. (a common theme on research topics on the Basis blog). For example, high caffeine intake over an extended period of time may tire the adrenal glands, which will impact your endocrine system and subsequent hormonal balance. In some people, caffeine activates the stress response, and may increase the body’s reaction to perceived stress during normal daily activities, such as in a work environment leading to anxiety.

In general, when consumed in moderation (about 3-4 cups per day) coffee has been linked to longevity, plus a reduced risk of cardiovascular disease, type 2 diabetes and Parkinson's. It can also reportedly reduce the risk of depression, improve overall mood and lifelong consumption helps prevent cognitive decline. 

The Caffeine In Coffee

Caffeine is the most widely consumed psychoactive drug worldwide and appears to exert most of its biological effects through the antagonism of the adenosine receptor.  

Adenosine is a brain chemical that dampens brain activity and prompts feelings of drowsiness. To prevent this, caffeine induces generally stimulatory effects in the central nervous system boosting energy and alertness levels. It can also enhance dopamine levels which is the chemical messenger of pleasure and gives us the ability to think and plan. The physiological effects of caffeine intake include acute elevation of blood pressure, increasing metabolic rate, and diuresis. Caffeine amongst other functions, boosts our energy and alertness levels and can be a performance enhancer, amplifying the strength of muscle contraction and offsetting some of the physiological and psychological effects of physical exertion.

Numerous studies demonstrate that caffeine can lead to a short-term boost in brain function, improving mood, reaction time, vigilance and general cognitive function.

Caffeine can also boost metabolism by 3–11% and exercise performance by 11–12%, on average.

However, some of these effects are likely short-term and if you drink coffee every day, you will build up a tolerance — and with it, make the effects less powerful.

Some interesting health-related facts on caffeine:

• The lethal dose of caffeine is about 10 grams, which is equivalent to the amount of caffeine in 100 cups of coffee. More on this below.
• Caffeine gets absorbed in the stomach and small intestine and then distributed throughout the body, including the brain. Following ingestion, caffeine is rapidly absorbed reaching peak concentrations in the circulation within an hour, although there is considerable individual variation.
• The U.S. Food and Drug Administration considers 400 milligrams (about 4 cups brewed coffee) a safe amount of caffeine for healthy adults to consume daily (with exceptions). 
• As a general rule of thumb, the lighter the bean, the more caffeine it has. So, a light roast is most likely to wake you up in the a.m. — or carry you through a lull in the afternoon — followed by a medium roast, and lastly a dark roast. As far as the type of coffee, reach for cold brew over iced or drip coffee on particularly groggy mornings. It has the most caffeine.

The Health Benefits of Coffee 

Considering the popularity of coffee, there are quite a few studies around its effect on health and humans. Some key findings from larger studies include:

• In a meta-analysis of observational studies including 330,677 participants, the authors found a 24% reduced risk of depression when comparing the highest (4.5 cups/day) to lowest (<1 cup) intakes of coffee. They found an 8% decreased risk of depression with each additional cup of coffee consumed. There was also a 28% reduced risk of depression comparing the highest to lowest intakes of caffeine, with the greatest benefit occurring with caffeine intakes between 68 and 509 mg a day (about 6 oz. to 2 cups of coffee). So…”Drink coffee, be happy?”
• In another n=498 134 study,  when coffee drinkers where compared with non-drinkers, those who drank 3-5 cups of coffee daily were 15% less likely to die early from all causes, including cardiovascular disease, suicide. Interestingly, It didn't matter whether you drank caffeinated or decaffeinated coffee, and it didn't matter whether you drank instant or brewed coffee. You still got that slightly lower chance of dying. 
• In an umbrella review of 21 meta analyses that examined the effects of caffeine ingestion on exercise performance, it seems that caffeine ingestion improves exercise performance in a broad range of exercise tasks and that the magnitude of the effect of caffeine is generally greater for aerobic as compared with anaerobic exercise. There are several hypothetical mechanisms for caffeine-mediated performance improvement, including via calcium release from the sarcoplasmic reticulum, through preservation of muscle glycogen through the inhibition of phosphodiesterase, and the antagonistic action of caffeine in the adenosine A1 and A2 receptors in the Central Nervous System.

Five step action plan to optimize your daily coffee consumption 

Health planning is important in order for us to stay energized, happy and perform at our optimum potential every day. So where does coffee fit in? For many of us, coffee is the first thing we look for as soon as we wake up. But is that the best way to utilize coffee?

1. Wait at least an hour after you wake up to drink coffee‍

For most people, the first thought after waking up is to drink some coffee to get rid of that morning grogginess. But that's not the best time to drink your coffee. In fact, it might be the worst time. When you wake up your body is producing cortisol, a hormone that’s released in response to stress and low blood glucose. Drinking coffee while that process is unfolding may interfere with your body’s natural production of cortisol and could lead your body to end up producing less cortisol, and relying more on caffeine to compensate. As a result, it also increases the person’s tolerance to caffeine because it replaces the natural cortisol-induced boost instead of adding to it. You should wait at least an hour before taking your first sip of coffee - this will likely have a much better impact on your energy levels.

But your wake up time is not the only time your cortisol levels naturally rise. In fact, they are elevated at three times of the day. So the best times to drink coffee — or caffeine in general — is between 2-4 hours after waking up, and between 6-9 hours after waking up. For most people that work a 9-5 that might look something like 10 a.m. and noon, and between 2 p.m. and 5 p.m.

2. Avoid flavorings & additives‍

While coffee and caffeine itself many have health benefits, how you drink your coffee may influence whether you're getting the full net benefit or if you're causing harm alongside the benefit. For example, additives like creamers, sweeteners and the like, can turn your coffee into more of a dessert than a beverage. Point in case, there are over 25,000 ways to order your coffee at Dunkin Donuts! Sugar or preservative packed additives are the easiest way to negate any positive effects caffeine has. Added sugar is arguably one of the worst ingredients in the modern diet. If you need something to break the bitterness of the coffee, try a natural sweetener like stevia. (avoid the artificial ones!).

3. No Coffee for at least 6 hours before bed.

‍Caffeine has a long half life - it can stay in your system for approximately 5 hours although that can vary based on the individual from 1.5-9.5 hours. Caffeine intake later in the day can interfere with good sleep quality. To be accurate, drinking around 2 cups of coffee in the morning reduces total sleep efficiency by 3% and sleep time by 10 minutes.  This is because caffeine dampens adenosine and melatonin production (another hormone promoting sleep), which are responsible for deep sleep. One has to be careful since the brain keeps secreting adenosine which stays in the brain until the receptors are free again. This is known as sleep pressure and its effects can cause decreased efficiency.  

Learn about the importance of The Circadian Rhythm

4. Don’t drink too much

In general, it’s recommended that you don’t exceed 1.1 mg per pound (2.5 mg per kg) of body weight per day. Given that the average cup of coffee contain around 95 mg of caffeine, this amounts to about two cups of coffee per day for someone weighing 176 pounds (80 kg). However, caffeine intake up to 400 mg per day (approx. 4 cups of coffee) is not associated with any adverse side effects in most people and the U.S. Food and Drug Administration considers that a safe amount for healthy adults to consume daily (with exceptions). 

As we mentioned, individual caffeine sensitivity varies. And the current state of your adrenal system also matters a lot. For example, if you’re drinking coffee continuously over the course of a couple weeks to compensate for a lack of sleep and deal with a stressful period at work, you’ll likely be looking at caffeine having a negative effect on your health. One effective way to assess your stress levels is tracking your HRV. 

Learn about HRV

A necessary part of a healthy routine?

It’s one thing to say that coffee may be good for you; it's another to say it's so good for you that drinking it should be recommended. And we're not there yet.

All of the favorable studies and all of the seemingly healthful ingredients in coffee are good news for coffee drinkers. But for people who don't drink coffee, there are many other ways to manage your energy levels without concerns around how it may influence your body’s natural melatonin and cortisol production.

It’s well known that caffeine gives us a boost. It does so by acting on our adrenal glands - the organs responsible for our stress response. But how you personally use caffeine in your day is nuanced based on how your body responds to caffeine and in what general state your body is in the moment. (a common theme on research topics on the Basis blog). For example, high caffeine intake over an extended period of time may tire the adrenal glands, which will impact your endocrine system and subsequent hormonal balance. In some people, caffeine activates the stress response, and may increase the body’s reaction to perceived stress during normal daily activities, such as in a work environment leading to anxiety. When consumed in moderation (about 3-4 cups per day) coffee has been linked to a longer life span, plus a reduced risk of cardiovascular disease, type 2 diabetes and Parkinson's. It can also reportedly reduce the risk of depression, improve overall mood and lifelong consumption helps prevent cognitive decline.