Caffeine is a natural stimulant that is among the most widely used ingredients in the world.
It stimulates the central nervous system, making you feel more awake. That is why the majority of those who are working on a night shift rely on caffeine.
Although it may cause adverse effects on anxiety and sleep, it has been reported in multiple studies to provide various health benefits, especially when taken in moderation.
Here we examine the recent studies conducted on caffeine and your health.
What is caffeine?
A natural stimulant found in coffee, tea, and cacao plants, caffeine can has been suggested to have energizing effects.
It increases the activity of the central nervous system, thus helping you stay awake and physically alert.
The first brewed tea was tracked by historians back in 2737 B.C.
Many years later, coffee was reportedly discovered by an Ethiopian shepherd who had observed the energizing effects of coffee to his goats.
Soft drinks containing caffeine started to hit the market in the late 1800s, followed by energy drinks.
Currently, a large number of people worldwide consume caffeinated products every day. What’s more, this number continues to go up in North America
How it works
Caffeine blocks the effects of adenosine, which is a naturally occurring substance that relaxes the brain, dilates blood vessels, and makes you feel tired.
The amount of adenosine normally increases over the day, making you want to go to sleep.
Caffeine connects to the adenosine receptors in the brain without activating them, thereby blocking the effects of adenosine, resulting in reduced tiredness and increased alertness.
In addition, caffeine can also be considered a psychoactive drug. It stimulates activity of norepinephrine and dopamine, which are neurotransmitters that help you pay attention and focus on your daily activities.
Caffeine-containing foods and drinks
Certain plants contain caffeine and these include tea leaves, kola nuts, coffee beans, and cocoa beans.
These plants are processed and mixed with different ingredients to produce caffeinated products, which certainly differ in caffeine content.
Below are some popular drinks with their respective caffeine contents per 8-oz serving:
Caffeine in brewed tea: 40–120 mg
Caffeine in cocoa beverage: 2–7 mg
Caffeine in chocolate milk: 2–7 mg
Caffeine in coffee: 102–200 mg
Caffeine in energy drinks: 50–160 mg
Caffeine in espresso: 240–720 mg
Caffeine in soft drinks: 20–40 mg
Caffeine in yerba mate: 65–130 mg
Decaffeinated coffee: 3–12 mg
Other caffeine-containing products include milk chocolate with 1–15 mg per ounce and dark chocolate harboring 5–35 mg per ounce.
Caffeine is not limited to foods and drinks. It can also be found in some over-the-counter drugs like painkillers.
What’s more, it is also commonly added to some commercial weight loss supplements.
Caffeine Benefits
Caffeine has metabolism-boosting and fat-burning effects
Caffeine’s ability to stimulate the central nervous system may result in improved metabolism and fat burning.
Multiple studies have shown that consuming 300 mg of caffeine per day may potentially help you burn an extra 79 calories every day. Although the amount may seem small, it can become significant in the long run, which can eventually lead to weight loss.
However, a 12-year study demonstrated very subtle effects, i.e. those who drank the most amount of coffee were, on average, only 0.8–1.1 pounds lighter than those who didn’t.
Caffeine may improve exercise performance
Interestingly, caffeine may increase the use of fat as fuel during exercise. This helps glucose stored in muscles last longer, thus deferring muscle exhaustion.
Caffeine has been shown to increase fatigue tolerance and improve muscle contraction.
Caffeine doses of 2.3 mg per pound of body weight taken 60 minutes post exercise have been observed by researchers to improve endurance performance by up to 5%.
At least 1.4 mg of caffeine per pound of body weight may suffice for you to experience the benefits.
Similar benefits were also reported in team sports, resistance exercises, and high intensity workouts.
What’s more, caffeine consumption may make workouts feel easier by reducing perceived exertion during exercise by 5.6%.
Caffeine may promote heart health
Caffeine consumption does not increase the risk of heart disease; in fact, it lowers it.
In fact, men and women who consumed 1–4 cups of coffee containing 100–400 mg of caffeine every day have been shown in research to have 16–18% lower risk of developing heart disease.
In addition, drinking 2–4 cups of coffee or green tea every day has been shown in other studies to lower the risk of stroke by 14–20%.
Although caffeine may slightly increase blood pressure in some people, the effect will likely fade when they consume coffee regularly.
Caffeine may help protect against diabetes.
People who consumed the most coffee have been noted in a review to have up to 29% lower risk of developing type 2 diabetes. Thus, those who have increased caffeine consumption may also experience the same benefit.
Additionally, it has also been observed that for every 200 mg of caffeine consumed, the risk drops by 12–14%.
Moreover, drinking decaffeinated coffee may also lower the risk of diabetes by 21%, indicating that coffee has other beneficial compounds which can help protect against type 2 diabetes.
Caffeine may enhance mood and brain function
Caffeine blocks the brain-signaling molecule adenosine, thus causing an increase in other signaling molecules like norepinephrine and dopamine.
These effects have been thought to be beneficial for your mood and brain function.
In fact, people who consumed 37.5–450 mg of caffeine have been reported in one review to experience improved reaction time, alertness, and short-term recall.
In addition, drinking 2–3 cups of coffee containing about 200–300 mg caffeine per day has been linked to a 45% reduction in suicide risk.
What’s more, caffeine consumption has been reported in another study to lead to 13% lower risk of depression.
It is important to note that more caffeine intake is not necessarily better when it comes to mood. For example, drinking another cup of coffee has been found in a study to produce no further benefits unless consumed at least 8 hours after the first cup.
Drinking 3–5 cups of tea or coffee per day has been found in multiple studies to potentially help lower the risk of brain diseases, including Parkinson’s and Alzheimer’s by 28–60%.
Aside from caffeine, coffee and tea also contain other potentially beneficial bioactive compounds.
Caffeine side effects
Moderate caffeine consumption is basically considered safe for healthy individuals.
However, when consumed in excess, it may lead to some adverse effects including irregular heartbeat, restlessness, anxiety, tremors, and insomnia.
In addition, too much caffeine intake may result in high blood pressure, headaches, and migraine in some individuals.
Pregnant women should also consider limiting their caffeine intake as this substance can easily cross the placenta, potentially increasing the risk of miscarriage or low birth weight.
Caffeine may also interact with some medications, including the antidepressant Luvox and muscle relaxant Zanaflex. Hence, those who are taking these drugs should avoid caffeine.
Recommended dosages: How much caffeine is too much?
According to the European Food Safety Authority (EFSA) and U.S. Department of Agriculture (USDA), consuming 400 mg of caffeine (equivalent to 2–4 cups of coffee) per day is considered safe.
A single dose of 500 mg of caffeine has been reported to lead to fatal overdoses.
Pregnant women should also limit their caffeine intake to 200 mg per day, according to the American College of Obstetricians and Gynecologists.
The Takeaway
Caffeine was once believed to be unhealthy. Thanks to early research for uncovering its numerous health benefits.
Thus, drinking tea or coffee in moderation can be a great way to lose weight and promote better health.
