Coffee tastes good - but is it good for you? More than half of Americans are java junkies, yet the average joe doesn't know beans about the health effects of our daily brew. In fact, scientists say there are grounds to claim that coffee has many effects on health - some good, some bad. Keep clicking as leading coffee researcher Dr. Rob van Dam, adjunct assistant professor of nutrition at Harvard School of Public Health and an associate professor at Yong Loo Lin School of Medicine in Singapore, filters coffee truth from coffee fallacy - and be prepared for some jolts...
TRUE OR FALSE: Coffee can cause high blood pressure
TRUE. Caffeine can increase blood pressure - but apparently mostly transiently. Long-term studies have found no link between regular coffee consumption and high blood pressure, a.k.a. hypertension. "Still, for persons with hypertension it may be worthwhile to see if switching to decaf improves control of blood pressure," says Dr. van Dam.
TRUE OR FALSE: Coffee can raise cholesterol
TRUE. Coffee beans contain a potent cholesterol-raising compound called cafestol. If you drink instant coffee or coffee that's passed through a paper filter, your brew will contain only a negligible amount of cafestol.
But traditional Turkish, Greek, Scandinavian coffee and coffee that's prepared via the French press method can contain high levels of cafestol. Studies have shown that drinking lots of these kinds of coffee can raise cholesterol levels and the risk of heart attack. In contrast, a large body of research suggests that regular consumption of filtered coffee does not increase risk for heart disease or stroke.
TRUE OR FALSE: Coffee fights depression
TRUE: Preliminary studies have shown that habitual consumption of coffee is linked to lower risk for depression, at least among women.
TRUE OR FALSE: Coffee can cause miscarriage
TRUE. Heavy coffee consumption during pregnancy has been linked to miscarriage and low birth weight. A developing fetus isn't good at metabolizing caffeine, and research has shown that the stimulant easily crosses the placenta. To limit the risk, doctors often urge women to have no more than one cup of coffee a day during pregnancy (or two cups of tea).
TRUE OR FALSE: Coffee contains lots of calories
FALSE: Coffee contains almost no calories - as long as you drink it black. But fancy brews sold by specialty coffee retailers are often loaded with sugar and fat - and oodles of calories that can contribute to weight gain. A single venti white chocolate mocha from Starbucks delivers 510 calories - roughly 25 percent of an adult's normal daily calorie intake.
TRUE OR FALSE: Coffee can cause diabetes
FALSE: People who drink coffee on a regular basis actually seem to have a lower-than-average risk for type 2 diabetes. The reduced risk has been seen with both caffeinated and decaf, which suggests that it's something other than caffeine that explains the effect. A compound known as chlorogenic acid is one possibility, as are other compounds like trigonelline and ligans.
TRUE OR FALSE: Coffee causes Parkinson's disease
FALSE: Studies have shown that men who drink lots of coffee have a below-average risk for Parkinson's, a brain condition marked by tremors and difficulty to coordinate movements. Animal studies suggest that caffeine prevents the death of nerve cells that produce the neurotransmitter dopamine, which is a core problem in Parkinson's.
In women, the relationship between caffeine intake and Parkinson's may be a bit more complicated. Recent research suggests that caffeine has a beneficial effect on women not using estrogen-replacement therapy, but not in those who do take hormones.
TRUE OR FALSE: Coffee causes liver damage
FALSE: Recent evidence suggests that coffee lowers the risk for both liver cirrhosis and liver cancer, though there's no clear explanation of the apparent protective effect. Similarly, concerns that heavy coffee consumption can increase the risk for other forms of cancer have not been confirmed in recent, more rigorous studies.
TRUE OR FALSE: Coffee protects against gout
TRUE: Recent studies have linked high consumption of both caffeinated and decaffeinated coffee to reduce risk of gout, a painful condition in which crystals of uric acid accumulate in the joints. In addition to reducing levels of uric acid in the bloodstream, coffee may reduce the risk of insulin resistance. That's a condition that precedes diabetes and is considered a risk factor for gout.