The Health Perks of Caffeine

If you’re like many adults, caffeine is part of your daily routine. According to a recent Dunkin’ Donuts study, 46 percent of all U.S. workers feel more productive with coffee.

But caffeine’s benefits don’t stop there. The latest research offers new insight about the health perks of this potent pick-me-up.

Caffeine is the ultimate power tool.
“Caffeine boosts brain­power and memory, makes you feel more vigorous, and improves mood,” says Harris R. Lieberman, Ph.D., a research psychologist with the U.S. Army Research Institute of Envi­ron­mental Medi­cine in Natick, Mass.

Caffeine blocks the action of adenosine, an organic compound that promotes sleep, to stimulate brain cells to fire up.

Blood levels of caffeine peak about 30 to 45 minutes after you’ve consumed it. But don’t gulp down two cups first thing to turbocharge your day.

A study Lieberman led involving U.S. Navy Seals found that an average of 300 mg of caffeine (equivalent to three cups of coffee or four cups of tea) consumed throughout the day is optimal for most people for peak mental and physical performance.

Coffee cuts endometrial cancer risk.
Downing daily cups of coffee can reduce the risk of endometrial cancer, the most common cancer of the female reproductive organs. Researchers from the Harvard School of Public Health found that women who drank three to four daily cups of java reduced their risk of endometrial cancer by 29 percent compared to women who drank little or no coffee.

Drink think: Coffee contains chlorogenic acid, an antioxidant that may prevent DNA damage. Its caffeine and other bioactive compounds may alter the levels of estrogen, insulin, C-peptide, and other hormones to inhibit the growth of cancer cells.

Be careful how you take your coffee, though. Adding sugar and cream could contribute to weight gain and insulin resistance. Keeping your weight in check and exercising regularly are the most powerful ways to prevent endometrial cancer.

Coffee helps derail diabetes.
The pooled results of 18 studies involving more than 450,000 people found that each daily cup of coffee consumed is associated with a 7 percent lower risk of diabetes. Follow-up studies show that coffee may reduce inflammation and improve insulin sensitivity.

But again, don’t OD on the stuff. Some studies link coffee consumption—more than three cups of coffee per day—with an increased risk of rheumatoid arthritis.

That cup of joe won’t make you go.

Women with urinary incontinence (UI)—the strong, sudden urge to go when you may not be anywhere near a bathroom—have long been told to avoid coffee and other caffeinated foods and beverages. It was thought that caffeine, a diuretic, may irritate the bladder and make things worse.

But a recent study shows that caffeine isn’t the culprit once thought. Researchers analyzed food questionnaire data from the Nurses’ Health Study and Nurses’ Health Study II from 21,564 women with moderate UI—who leaked urine one to three times per month—over two years.

They found that caffeine didn’t cause more problems. Whether women routinely drank just one cup of coffee daily or downed four or more cups, those who kept up their caffeine habit didn’t experience more bouts of UI over time. In women whose symptoms had gotten worse, there was no link to caffeine, the researchers found.

If you’ve got UI, there’s no need to give up caffeine to manage the condition.

Coffee won’t weaken your bones.
Although a teeny bit of calcium does leach from your bones when you drink full-strength java, it’s not enough to be harmful, even if you drink a lot of coffee. Still, if you want to make up the difference, pour in one to two tablespoons of skim milk or have a skim latte (half steamed skim milk, half coffee) instead.

How much is too much? “On average, most adults will notice no side effects from caffeine at 300 milligrams or fewer a day,” says Herbert Muncie Jr., M.D., professor of family medicine at LSU School of Medicine in New Orleans.

That’s the caffeine equivalent of roughly 28 ounces (or three and a half cups) of regular coffee. But know your limit and stick to it.

“Find out what’s right for you. There are genetic differences that seem to predict how quickly people metabolize caffeine. Some people need less caffeine than others,” Lieberman says.

If your blood pressure is elevated or you’re sensitive to the effects of caffeine (the jitters, restlessness, anxiety, heart palpitations, heartburn, insomnia), consider avoiding caffeine altogether.

Likewise, if you’re pregnant or trying to conceive, “reduce your intake to one caffeinated beverage a day or less,” says Lisa Mazzullo, M.D., an ob/gyn in Chicago and coauthor of Before Your Pregnancy. Consuming too much caffeine may increase your risk of low birth weight or miscarriage.

Timing is important too. Caffeine generally takes eight to 12 hours to get out of your system. If sleeping well is a problem, avoid any caffeine after noon. Besides obvious sources, such as caffeinated coffee (103 mg caffeine in 6 ounces), tea (36 mg in 6 ounces), and cola beverages (49 mg in 12 ounces), try to steer clear of hidden caffeine in foods like coffee-flavored yogurt (44.5 mg in 8 ounces) and chocolate (6 mg in 1 ounce). BW