Coffee doesn’t just keep you awake, it may literally make you smarter as well.
The active ingredient in coffee is caffeine, which is a stimulant and the most commonly consumed psychoactive substance in the world.
Caffeine’s primary mechanism in the brain is blocking the effects of an inhibitory neurotransmitter called Adenosine.
By blocking the inhibitory effects of Adenosine, caffeine actually increases neuronal firing in the brain and the release of other neurotransmitters like dopamine and norepinephrine (1, 2).
Many controlled trials have examined the effects of caffeine on the brain, demonstrating that caffeine can improve mood, reaction time, memory, vigilance and general cognitive function (3).
Bottom Line: Caffeine potently blocks an inhibitory neurotransmitter in the brain, leading to a net stimulant effect. Controlled trials show that caffeine improves both mood and brain function.
There’s a good reason why you will find caffeine in most commercial fat burning supplements.
Caffeine, partly due to its stimulant effect on the central nervous system, both raises metabolism and increases the oxidation of fatty acids (4, 5, 6).
Caffeine can also improve athletic performance by several mechanisms, including by mobilizing fatty acids from the fat tissues (7, 8).
In two separate meta-analyses, caffeine was found to increase exercise performance by 11-12% on average (9, 10).
Bottom Line: Caffeine raises the metabolic rate and helps to mobilize fatty acids from the fat tissues. It can also enhance physical performance.
Type II diabetes is a lifestyle-related disease that has reached epidemic proportions, having increased 10-fold in a few decades and now afflicting about 300 million people.
This disease is characterized by high blood glucose levels due to insulin resistance or an inability to produce insulin.
In observational studies, coffee has been repeatedly associated with a lower risk of diabetes. The reduction in risk ranges from 23% all the way up to 67% (11, 12, 13, 14).
A massive review article looked at 18 studies with a total of 457.922 participants. Each additional cup of coffee per day lowered the risk of diabetes by 7%. The more coffee people drank, the lower their risk (15).
Bottom Line: Drinking coffee is associated with a drastically reduced risk of type II diabetes. People who drink several cups per day are the least likely to become diabetic.
Not only can coffee make you smarter in the short term, it may also protect your brain in old age.
Alzheimer’s disease is the most common neurodegenerative disorder in the world and a leading cause of dementia.
In prospective studies, coffee drinkers have up to a 60% lower risk of Alzheimer’s and dementia (16, 17).
Parkinson’s is the second most common neurodegenerative disorder, characterized by death of dopamine-generating neurons in the brain. Coffee may lower the risk of Parkinson’s by 32-60% (18, 19, 20, 21).
Bottom Line: Coffee is associated with a much lower risk of dementia and the neurodegenerative disorders Alzheimer’s and Parkinson’s.
The liver is a remarkable organ that carries out hundreds of vital functions in the body.
It is very vulnerable to modern insults such as excess consumption of alcohol and fructose.
Cirrhosis is the end stage of liver damage caused by diseases like alcoholism and hepatitis, where liver tissue has been largely replaced by scar tissue.
Multiple studies have shown that coffee can lower the risk of cirrhosis by as much as 80%, the strongest effect for those who drank 4 or more cups per day (22,23, 24).
Coffee may also lower the risk of liver cancer by around 40% (25, 26).
Bottom Line: Coffee appears to be protective against certain liver disorders, lowering the risk of liver cancer by 40% and cirrhosis by as much as 80%.
Many people still seem to think that coffee is unhealthy.
This isn’t surprising though, since it is very common for conventional wisdom to be at exact odds with what the actual studies say.
In two very large prospective epidemiological studies, drinking coffee was associated with a lower risk of death by all causes (27).
This effect is particularly profound in type II diabetics, one study showing that coffee drinkers had a 30% lower risk of death during a 20 year period (28).
Bottom Line: Coffee consumption has been associated with a lower risk of death in prospective epidemiological studies, especially in type II diabetics.
Coffee isn’t just black water.
Many of the nutrients in the coffee beans do make it into the final drink, which actually contains a decent amount of vitamins and minerals.
A cup of coffee contains (29):
May not seem like much, but if you drink several cups of coffee per day then this quickly adds up.
But this isn’t all. Coffee also contains a massive amount of antioxidants.
In fact, coffee is the biggest source of antioxidants in the western diet, outranking both fruits and vegetables combined (30, 31, 32).