Caffeine is found in many foods and drinks, making coffee the second most consumed beverage among us. This substance shows potent effects on our health and metabolism. Now the question is, what are the main health benefits of caffeine?
In this article we'll go through an introduction to caffeine, to then take you into the main benefits of this substance.
Scroll down and enjoy!
Table of Contents
CAFFEINE
Caffeine is an alkaloid compound of the methylxantine class. With 85% of the U.S population consuming at least one caffeinated beverage, caffeine is considered the most widely consumed psychoactive drug (study).
Caffeine shows a long list of health benefits, but it is primarly known for its stimulant effects (study). In fact, ancient societies already knew about it, using caffeine as a medicinal and recreational drug (source)
Coffee finds its roots in Arabia. While Yemen was the first country to cultivate coffee, it was in Turkey where they first roasted the green coffee beans (study). Found in more than 60 different plants, caffeine may act as a very potent plant pesticide, providing a barrier of protection to the plant (study).
Sources of Caffeine
Caffeine is found in a wide variety of drink and foods. Coffee, tea, and mate tea are the most popular caffeinated beverages (study). Other foods like cocoa or kola nuts contain some caffeine as well (study).
Caffeine content not only differs between different sources. The same source, let's say coffee, can provide a different dose depending on the type of bean used, method of preparation... (study)
Coffee
Coffee is the most popular caffeinated beverage. It contains around 1.1-2.2% caffeine. An average cup (250ml) contains an average of 95mg caffeine (study).
This amount may vary depending on the bean used, or even the method of preparation. Dark roasted beans are lighter than light roasted beans, and you usually need a greater amount of dark roast to make coffee. Therefore, dark roasts generally contain larger amounts of caffeine. But roasting itself doesn't affect caffeine content (study)
Tea
Tea leaves contain 3.5% caffeine. It contains higher caffeine concentrations than coffee, but you'd use less tea leaves than you would with coffee. So tea beverages contain less caffeine than coffee (study)
Black, green and white tea come from the same plant, Camellia sinensis. The difference between them comes in the extent of oxidation of the leaves. A regular tea cup (250ml) of tea contains around 45mg, but it largely depends on the type of tea used. White tea, for instance, provides around 6mg of caffeine per cup.
The preparation method and duration of the infusion also depends on caffeine content. Caffeine extraction is higher as infusion stays for longer (study)
MAIN HEALTH BENEFITS OF CAFFEINE
Caffeine interacts with the cardiovascular and central nervous system (study). These interactions interfere with the locomotor activity, blood flow, alertness and awakeness levels, and much more (study).
Besides its stimulant effects, acute caffeine intakes can be a great aid to improve our health and metabolism.
Stimulant Effect
Caffeine is widely known for its stimulant effect, acting as an antagonist of adenosine receptor (study). Because adenosine and caffeine compete for the same receptor, the presece of caffeine will lead to an inhibition of adenosine.
As adenosine accumulate and bind to its receptor, it causes sleepiness and tireness (source) Because caffeine prevent that to happen, it produces a potent stimulant effects and delays sleepiness.
Increases Alertness
Alertness is a subjective measure of awakeness. Since caffeine acts stimulant our central nervous system (CNS) it will indirectly increase our alertness levels as well (study).
Norepinephrine and epinephrine are hormones modulating alertness and our mood. As caffeine interacts with the CNS, it modulates hormone secretion as well (study).
Caffeine stimulates norepinephrine and epinephrine secretion, increasing therefore alertness and improving your mood (study)
Cognitive Performance
Caffeine also modulates your cognitive function. With a high concentration of adenosin receptors in the hippocampus, cortex, cerebellum and hypothalamus (study), caffeine stimualtes catecholamine production and release. These catecholamines include epinephrine (adrenaline), norepinephrine (noradrenaline), and dopamine.
Caffeine intake increases alertness, improves response time and increases ability to learn and remember passive things (study). However, the cognitive effects of caffeine are limited, since it doesn't interfere with the brain or any of the parts involved in brain function directly.
Caffeine acts as Fat Burner
Caffeine shows to increase resting metabolic rate by 3-4% (study). By slightly increasing calorie expenditure, we may lose fat to a faster rate and more easily.
Caffeine may also improve fat oxidation directly. During aerobic exercise and physical activity, caffeine improves mean fat oxidation (MFO) (study). Not only during exercise, but acute caffeine intakes also increase fat burning directly as much as 29% in lean subjects (study)
Caffeine improves sports performance
Caffeine, due to its stimulant effect and role in the central nervous system, can improve your sports performance (study).
The antagonistic effect of adenosine receptors delays muscle fatigue and makes you feel more energetic and awaken (study) But that's not all.
Caffeine can also improve sports performance directly, enhancing fat oxidation and preserving muscle glycogen, and improving muscle contraction (study)
Prevents Alzheimer’s Disease
Azheimer's Disease is a neurodegenerative disease and the leading cause of dementia worldwide. Common in the elderly, this mental disorder doesn't have cure. But we can still try to prevent it.
Caffeine drinkers show up to a 65% lower risk of Alzheimer's Disease (study). By acting as a neuroprotector, caffeine is able to prevent excess cognitive decline. It improves short-term memory and enhances the learning process (study).
However, caffeine is not the ultimate cure and prevention for dementia. Instead, healthy lifestyle and proper diet are more efficient at lowering the risk of Alzheimer's and similar cognitive declines as we age (study)
How Much Caffeine is Safe?
Health Organizations such as USDA or EFSA define a safe caffeine intake as up to 400 mg per day, 200 mg per single dose, or 1.4 mg per pound (3 mg per kg) of body weight. (source) However, caffeine content differs widely depending on the plant of origin, format, and even the method of preparation (study).
Health concerns may come if these intakes are overpassed. Specially bodybuilders and fitness lovers abuse of caffeine, taking huge amounts before training (case study). If blood caffeine concentrations are too high, it will cause toxicity, increased heart rate, insomnia, headaches, anxiety,... (study)
CONCLUSION
Caffeinated beverages are one of the most consumed drinks worldwide. Caffeine, as the main bioactive compound of these drinks, show interesting health benefits.
In this post we have reviewed the main health benefits of caffeine. Acting on the central nervous and cardiovascular system, caffeine can improve your working memory, alertness and reaction time, sports performance, fat oxidation, and prevent alzheimer's disease and dementia.
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