1. It may help ward off depression.
Anyone who perks up after the first sip of morning coffee will tell you that it has mood-boosting effects. Now there's proof: A study from the Harvard School of Public Health, published last month in the Archives of Internal Medicine, found that women who regularly drink fully caffeinated coffee have a 20% lower risk of depression than non-coffee drinkers. The study, which followed a group of women for 10 years, found that as more coffee was consumed (up to six cups per day), the likelihood of depression decreased.
2. It may help promote a healthy weight.
Drinking an espresso or cappuccino after a meal is more than a rela habit. "When you drink coffee after a meal, it causes your body to more slowly process the meal you just ate," says Chris Kilham, medical researcher, founder of Medicine Hunter, Inc. and author of Psyche Delicacies. According to David Levitsky, PhD, professor of nutritional science at Cornell University, "Caffeine decreases the rate at which the stomach dumps its contents into the duodenum—a part of the small intestine where digestion takes place—and also increases metabolic rate." Keep in mind, though, that java isn't a miracle brew: Downing it after dinner won't make the pounds melt away; rather, sipping a cup post-meal could, in small part, help promote a healthy weight.
3. It may boost fertility in men.
"Studies have shown that caffeine has a positive effect on sperm motility—the ability of sperm to move toward an egg—and could increase your chances of [getting pregnant]," says John Wilcox, MD, FACOG, managing partner and reproductive endocrinologist at HRC Fertility in California. In fact, a study conducted at the University of Sao Paulo found that sperm motility was markedly higher in coffee drinkers versus non coffee-drinkers. And it turns out that it doesn't matter whether you drink one or ten cups a day: The only detectable difference was found between coffee drinkers and non-coffee drinkers.
4. It can harbor bacteria.
When you think of the germiest places in your house, you probably picture the kitchen sink or garbage disposal. But your coffee machine's reservoir also tops the list. A study performed by NSF International, a not-for-profit health and safety organization, found that the coffee reservoirs they studied were "loaded with yeast and mold organisms," says Robert Donofrio, PhD, director of NSF International's microbiology labs. "Hardly any of the volunteers we spoke to cleaned or disinfected their reservoirs. The residual water in that area, plus the fact that it's a humid part of the machine, contributed to bacterial growth." To properly clean your coffee machine, follow the manufacturer's cleaning protocol. If nothing is specified, clean it once a month by adding three or four cups of undiluted vinegar to the reservoir, allowing it to sit for 30 minutes and then running the vinegar through the unit. Finish by adding fresh water to the reservoir and running the machine through two or three cycles to wash away vinegar residue.
5. It may reduce the risk of skin cancer.
Staying out of the sun and regularly applying a liberal amount of SPF should always be your number one line of defense against skin cancer. That said, a new study out of Brigham and Women's Hospital found that women who drank more than three cups of coffee a day had a 20% lower risk for basal cell carcinoma, and men had a 9% reduced risk. However, the research did not indicate that coffee consumption reduced the risk of squamous cell carcinoma or melanoma, the deadliest form of skin cancer, making it all the more important to protect your skin when outdoors.
6. It's not truly addictive.
While many people claim that they can't make it through the day without a few cups of java, Liz Applegate, PhD, faculty member and director of sports nutrition at the University of California at Davis, explains that caffeine is not addictive. "Caffeine is a mild stimulant, and the World Health Organization states that it is wrong to compare caffeine intake to drug addiction, since people can reduce or eliminate caffeine from their diet without the serious psychological or physical problems that result from a true addiction." However, serious coffee drinkers may experience symptoms such as fatigue and irritability if they reduce their intake. According to Dr. Applegate, people who consume 600 milligrams of caffeine (about six small cups of coffee) daily are most likely to experience these symptoms, but they will usually resolve themselves after a few days.
7. It doesn't necessarily cause stomach pain.
If you've ever blamed java for stomach discomfort, you might want to visit your doctor to see what else could be at the root of the problem. According to Lauren Gerson, MD, MSc, associate professor of medicine and gastroenterology at the Stanford University School of Medicine, "There is no evidence from reviewed studies that coffee causes ulcers or more pain in patients with documented ulcers." She also notes that there is no evidence that coffee could be the cause of stomach pain in patients with indigestion. However, there is one type of digestive issue that coffee can aggravate; Dr. Gerson explains that drinking coffee may worsen heartburn symptoms, since it stimulates the stomach to produce gastric acid.