Your morning—or afternoon—cup of Joe doesn't have to be a guilty pleasure anymore.

Your morning-or afternoon-cup of Joe doesn't have to be a guilty pleasure anymore.

Americans drink 3.6 billion ounces of coffee each year. And we're buzzing more than ever for "specialty coffee" (industry-speak for high-end brew). It's the drink we hate to love. Even though two-thirds of us drink it daily, 32 percent of us still stress about whether it's really safe. "Coffee is so pleasurable," says Miriam Nelson, Ph.D., nutrition researcher and director of the Sustainability Institute at the University of New Hampshire. "But when something is that enjoyable, we automatically assume it must be sinful." It's time to relax. Research reveals that this brew improves reaction time and alertness, which is key when, say, the car in front of you suddenly stops short. Studies also show coffee consumption reduces risk of type 2 diabetes and depression and may help treat symptoms of Parkinson's disease. But how much should you drink? Experts green light 400 milligrams of caffeine a day. Thats about 6-ounces of espresso, 18-ounces of Starbucks Blonde Roasts, 24-ounces of Starbucks Dark Roasts, 32-ounces of cold brew or 32-ounces of home-brewed drip coffee.

Still skeptical? Here are the six biggest java myths, busted.


Health myth: Coffee is dehydrating.

Nobody ever landed in the emergency room with a case of dehydration from chugging too many cold brews. In fact, coffee can actually help you meet your fluid needs, according to the Institute of Medicine. And a brand-new American Journal of Clinical Nutrition study strengthens that point. When researchers tested 13 different drinks to find out how hydrating they were, coffee ranked comparably to water.

Health myth: The darker the roast the bigger the buzz.

When you're looking for a boost, a deep, dark roast might seem like a logical choice. But light roasts are where the caffeine is really at. Roasting burns off some of coffee's caffeine, so as beans turn from green to gold to ebony they become less potent. If you need a kick, go with paler beans. You'll gain up to 39 percent more caffeine than you'd net from their darker cousins.

Health myth: If you have heart troubles, stick with decaf.

The truth: Caffeinated coffee works like adrenaline, making your heart pump harder and faster. So it's no surprise that people with irregular heartbeats are often advised to steer clear. But that could be overkill. A 2016 Journal of the American Heart Association study found that caffeinated drinks, including coffee, didn't cause any increase in irregular heartbeats in elderly people. Translation: "If coffee doesn't seem to affect a person's arrhythmia symptoms, it's OK to consume it in moderation as long as they check with their physician," says Gregory Marcus, M.D., director of clinical research in the division of cardiology at the University of San Francisco and an author of the study.

Health myth: Instant coffee is inferior.

Flavor-wise, instant joe may seem second rate, but not where antioxidants are concerned. A 2012 Food Chemistry study found that instant served up more antioxidants, particularly chlorogenic acid, than fresh brewed. "Chlorogenic acid may potentially reduce the risk of diabetes by slowing glucose absorption into the bloodstream after a meal," says Edward Giovannucci, M.D., a professor of nutrition and epidemiology at Harvard School of Public Health.

Health myth: The more coffee you drink, the more you'll need.

The truth: You do build up a slightly greater caffeine tolerance as you drink increasingly more coffee, but most of us know when to say when, says Harris Lieberman, Ph.D., a psychologist at the U.S. Army Research Institute of Environmental Medicine in Natick, Massachusetts. "If too much makes a person feel keyed up, they very quickly learn how much they can tolerate, so they naturally learn to self-regulate," he adds . The reason may be genetic. A 2015 Molecular Psychiatry study identified six new genetic variations that impact how we metabolize and react to coffee, providing a hint as to why one person can pound four cups and feel fine, while another feels jittery after just one.

Health myth: A cup of coffee before a workout can help you go longer and stronger.

Not always. For many people, coffee's stimulant action makes exercise seem easier. But if you have a sensitive stomach-or if you're not in the habit of a pre-workout cup to begin with-swigging a mug of coffee before a run or bike ride could do a number on your digestive system. Plus, the optimal amount varies substantially from person to person. "The range is so broad, one or two cups is perfectly reasonable but there are people who need more," says Nelson. "You really need to experiment to find the perfect balance between just enough to aid you, but not too much to impede you."

September/October 2016