Caffeine: it’s a substance that’s been used for centuries, in countries around the world, and extensively studied by researchers. Yet despite the wealth of scientific data that exists, many feel confused about it. How do you distinguish the facts about caffeine from the myths? Below are five popular beliefs about caffeine—do you know which are true and which are false?
Caffeine Is Bad For You
The origin of this belief is unclear, though some think it arose because coffee consumption is often paired with other unhealthy lifestyle choices, like smoking or eating trans-fat-laden doughnuts. However, the bulk of current research suggests that there are no health risks associated with regular, moderate caffeine consumption (the equivalent of up to four cups of coffee a day).
Indeed, some studies suggest that caffeinated beverages like coffee and tea may have health benefits. Regular coffee consumption is linked to a reduced risk of type II diabetes and some cancers, while teas have antioxidant and anti-inflammatory properties. While a normal intake of caffeine is likely to be safe, there are risks associated with very high intakes (about 500 milligrams or more at once). An overdose of caffeine can cause anxiety, muscle twitching, rapid heartbeat, and stomach distress, among other symptoms.
The verdict: false for most people, though very high doses can be dangerous.
Caffeine Dehydrates you
The idea that caffeinated beverages are dehydrating is a widespread belief, but is it true?
Studies have shown that caffeine does have a diuretic effect, meaning that it increases water loss from the body. However, in most cases, any potential water loss is offset by the water consumed as part of the caffeinated beverage. The average cup of coffee, for instance, is 98% water.
Additionally, some studies suggest that the diuretic effect of caffeine is more pronounced in people who don’t regularly consume the substance; for regular coffee and tea drinkers, the effect will be weaker.
The verdict: false, for most intents and purposes.
Caffeine Can Help You Lose Weight
Many people believe in a link between caffeine and weight loss, and it’s true that caffeine is added to many diet supplements for its supposed metabolism-boosting and appetite-suppressing properties. But does it really work?
The evidence is mixed—some studies have found that caffeine did reduce subjects’ appetite, but other studies have found no appetite reduction effect from caffeine. While caffeine can stimulate the metabolism, most experts agree that the fat-burning effect is likely to be minimal, and out-weighed by other factors that affect weight loss. Studies do suggest, however, that caffeine can give you a performance-enhancing boost in the gym. Athletes who consume a small amount of caffeine before a workout have been found to exert more energy and burn more calories.
The verdict: Partly true, but the effect is likely to be small, and to vary by individual.
Caffeine Can Sober You Up
Someone who’s had too much alcohol might ask for coffee or an energy drink to “snap them out of it,” but does it really work? While caffeine can create a feeling of alertness that hides alcohol’s depressant effects, it cannot reduce or counteract the effects of alcohol. In fact, it can be dangerous to combine the two substances, as drinkers who are stimulated by the caffeine may not realize how much alcohol they have consumed. People who combine alcohol and caffeinated beverages are also more likely to binge drink.
The verdict: false.
Caffeine Is Addictive—And Quitting It Can Cause Withdrawal Symptoms
Many people are familiar with the “caffeine headache” that results when you skip your regular morning coffee, and as a result, the idea that caffeine is addictive has taken hold in the popular imagination. But is it true?
People don’t use caffeine compulsively and pathologically enough to qualify as “addicts” in the strict sense of the word, but many people have developed a physical dependence on caffeine. A physical dependence occurs when a substance is used chronically, and the body undergoes physiological changes to accommodate it. Studies have shown that people who consume 100 milligrams of caffeine a day (about the amount in one cup of coffee) can develop a dependence on the substance.
Physical dependence on caffeine is why many people who suddenly stop their regular consumption will experience a variety of side effects, including headaches, irritability, fatigue, and difficulty concentrating. But the majority will find that these symptoms pass within a week or two, and the withdrawal from caffeine is not dangerous like withdrawals from illicit drugs are.
The verdict: somewhat true, but withdrawal symptoms will vary from person to person, and are temporary.