This Is the Exact Amount of Coffee You Should Drink, According to a Harvard Brain Expert

Scientists agree: Drinking coffee is good for you. That’s good news if, like most Americans, you enjoy coffee and perhaps rely on it to help you wake up in the morning or stay alert during the day.

In the last couple of years, more detailed research on coffee has sought to zero in on just how much coffee you should drink every day for maximum health and brain benefits. They’ve found the answer–you should drink three cups. That advice comes from Uma Maidoo, MD, who’s been described as a “triple threat”–a Harvard-trained psychiatrist, trained nutrition specialist, and trained chef. She’s also the author of the bestseller This Is Your Brain on Food. In an article at CNBC.com, Maidoo explains how she herself uses coffee as part of her daily routine to boost her own brain function. (Maidoo’s routine includes putting shots of espresso into golden milk, which sounds like a fantastic idea to me.) 

Why three cups? Maidoo points to a study in which researchers tracked both the coffee consumption and cognitive health of 676 elderly men over ten years. They found that the coffee drinkers had less than half the cognitive decline as the non-coffee drinkers did. And those who drank three cups a day had the least decline of all. A larger Harvard study, with a total 208,501 participants, both men and women, examined the likelihood of death over more than 20 years. It found that participants who drank coffee were less likely to die than those who didn’t, with the greatest longevity benefit going to those who drank between 3.1 and 5 cups a day.

If you want the maximum benefits from your coffee habit, make sure to follow these three rules:

Many sophisticated coffee drinkers favor espresso, French press, and Turkish coffee–and some love the Scandinavian tradition of boiling coffee with an egg in it (sometimes including the shell), which pulls together the grounds. Unfortunately, all these versions of coffee can be bad for you. When coffee is made without a paper filter, “oily chemicals called diterpenes come through that can raise artery-damaging LDL cholesterol,” according to The New York Times’ Jane Brody. Brody, who uses coffee pods, actually dissected one to make sure it contained a paper filter (it did).

Coffee may be good for you, but sugar is very bad for you. So if drinking coffee means getting a highly sweetened latte concoction from your favorite barista, you won’t be doing your health any favors. Especially when you consider that espresso-based drinks like latte are unfiltered.

A better strategy is to make your own drip coffee at home, using fresh-ground beans for both better flavor and better control over exactly what goes into your coffee. For added fun, put the $4 to $6 you would have spent at the coffee shop aside for every homemade cup you drink, then use that money for a special treat.

This is Maidoo’s advice and it’s an important tip to follow because every body is different, and each of us may react differently to coffee’s effects. If it makes you feel jittery, cut back your consumption or cut it out altogether. The same holds true if you have trouble sleeping. Caffeine can affect your ability to fall asleep and also whether you reach the deep sleep stage that your body and brain both need to stay healthy.

At the same time, pay attention to whether coffee lightens your mood, which it might. One of the most intriguing findings from the Harvard study is that coffee drinkers were half as likely to commit suicide as non-coffee drinkers. Researchers believe the explanation may be that coffee boosts brain chemicals that have an anti-depressive effect.

There’s a growing audience of Inc.com readers who receive a daily text from me with a self-care or motivational micro-challenge or idea. Often they text me back and we wind up in a conversation. (Interested in joining? You can learn more here.) Many are entrepreneurs and business leaders, and they tell me that a bright mood and positive attitude makes all the difference when you’re running a business or leading a team.