Most people rely on caffeine to stay alert. But researchers suggest that it may do far more—lowering the risk of Parkinson’s disease and gallstones, for example. Here’s what you may not know about the times that caffeine is good for you.
* This information does not apply to women who are pregnant (or trying to become pregnant) or to children. Nor does it apply to caffeine powder or highly concentrated liquid caffeine, which can be lethal.
1. Caffeine lowers the risk of Parkinson’s Disease
“There is fairly convincing evidence that people who drink coffee or consume caffeine regularly have a lower risk of developing Parkinson’s Disease,” says researcher Alberto Ascherio of the Harvard School of Public Health in Boston.
An estimated 1.5 million Americans have Parkinson’s disease. They experience trembling in the hands, arms, legs, jaw, and face. Their limbs and trunk become stiff. They move slowly and lose balance and coordination. As symptoms worsen, they may have difficulty walking, talking, or performing other simple tasks.
Parkinson’s is caused by the loss of brain cells that produce chemical messengers called dopamine. But it seems caffeine is good for you in stemming that loss.
“When researchers exposed mice to a chemical that causes a loss of dopaminergic neurons in a pattern similar to that observed in Parkinson’s disease, those that had first been given caffeine equivalent to moderate amounts of coffee in humans lost fewer neurons than those not given caffeine,” explains Ascherio.
In a meta-analysis that pooled 13 studies, drinkers of regular coffee – but not decaf – had a 30 percent lower risk of Parkinson’s than non-drinkers.
And it doesn’t take much caffeine—just 100 to 200 milligrams a day. “Even a modest amount – the equivalent of between one and two cups of coffee per day—is associated with a lower risk,” notes Ascherio.
2. Caffeine reduces gallstones
In the Nurses’ Health Study, which tracked nearly 81,000 women for 20 years, and the Health Professionals Follow-Up Study, which tracked 46,000 men for 10 years, those who drank two to three cups of regular coffee a day had about a 20 percent lower risk of gallstones than non-drinkers.
“Tea, decaf coffee, and caffeinated soft drinks weren’t protective, probably because they don’t contain enough of what’s making the difference— caffeine,” says Michael Leitzmann, formerly of the National Cancer Institute in Bethesda, Maryland.
One theory: caffeine is good for you because it may stimulate the gallbladder to contract, which helps empty it of stone-forming cholesterol and bile pigments.
3. Caffeine improves alertness
Caffeine improves alertness and reaction time in people, whether they’re habitual consumers of caffeine or not,” says Harris Lieberman, a psychologist at the U.S. Army Research Institute of Environmental Medicine in Natick, Massachusetts.
In the sleep-deprived, however, caffeine has a more striking impact. “It improves almost everything you can measure,” says Lieberman. “It makes you more alert, it seems like you can perform complex tasks better, and your memory is better.”
“People who are falling asleep on the job can’t do much of anything,” says Lieberman. “If you give them something that wakes them up and makes them focus, they’re going to do better.”
4. Caffeine makes you happier
After consuming anywhere from 20 mg to 200 mg of caffeine, “people report increased well-being, happiness, energy, alertness, and sociability,” says caffeine expert Roland Griffiths of the Johns Hopkins School of Medicine in Baltimore.
That may be why three studies that tracked more than 200,000 men and women for up to 20 years found that those who drank at least two cups of regular coffee a day were about half as likely to commit suicide as those who drank one cup or less a week.
5. Caffeine boosts endurance
Caffeine helps the body burn fat instead of carbohydrates, and it blunts the perception of pain. Both can boost endurance.
For example, endurance runners who ran to exhaustion on a treadmill lasted an average of 32 minutes without caffeine, but made it to 42 minutes after drinking coffee with around 250 mg of caffeine.
6. Caffeine is an analgesic
When you get a headache, the blood vessels in your brain dilate, or become wider. Caffeine causes blood vessels to constrict, which may explain why it can help relieve headache pain.
“It’s also a mild analgesic, or painkiller, and it has the ability to increase the availability of other analgesics that it’s combined with,” says Robert Shapiro, a headache expert at the University of Vermont College of Medicine in Burlington.
7. Caffeine slows cognitive decline
Caffeine may protect your brain from cognitive decline.
“In our study of people who already had an increased risk of cognitive decline because of cardiovascular risk factors, consuming about 500 milligrams of caffeine a day was strongly associated with memory preservation,” says Harvard’s Jae Hee Kang.
“It seems to require high levels of caffeine—four or five cups of coffee a day.”
The study found no lower risk among people who drank decaf or cola or tea, possibly because they got less caffeine. Until a trial tests caffeine against a placebo, though, it’s not clear that it protects the brain. Even so, researchers have some reason to expect that caffeine may help.
8. Caffeine may lower the risk of kidney stones
Researchers tracked nearly 218,000 nurses and health professionals for roughly eight years. People who typically consumed about 350 milligrams of caffeine a day had a 20 to 25 percent lower risk of kidney stones than those who consumed little or no caffeine.
The researchers, however, couldn’t tell if coffee, rather than caffeine, explained the lower risk. When they looked at people who drank less than one cup of caffeinated coffee per day, their caffeine from other sources was linked to a lower risk of kidney stones in men, but not in women.
Roughly 6,000 participants provided 24-hour urine samples. Those who consumed the most caffeine had lower concentrations of calcium oxalate in their urine, which could be important since most kidney stones are made of calcium oxalate.
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