Coffee drinkers, here is yet another reason to sip some java: Your morning blend just might help you live longer, finds a new study, which is just the latest in a long line of other recent studies with similar findings. But sit tight, say nutritionists. While coffee appears to have its share of benefits, it is definitely possible to get too much of a good thing.
The study, published in the July 2018 issue of JAMA Internal Medicine, aimed to look at whether heavy coffee consumption — defined as eight or more cups per day — increased the risk of dying. The researchers looked at data from the UK Biobank for nearly 500,000 British people who were 38 to 73 years old, nonsmokers and not pregnant. Seventy-eight percent were coffee drinkers.
Because more than one study has suggested fast caffeine metabolizers are at greater risk of cardiovascular disease and slow metabolizers are at greater risk of high blood pressure and heart attack, the researchers also looked at participants' genetic profiles to weed out those who metabolized coffee more quickly or more slowly than average.
Participants reported the average number cups of coffee they drank a day as well as the type of coffee. Over the course of 10 years (2006 to 2016), people who drank coffee were at lower risk of death from all causes, including cancer, cardiovascular disease and respiratory disease — even those who drank eight or more cups per day.
In fact, of the more than 14,000 people who died during the study, those who drank a full six to seven cups of coffee were actually the least likely to die. Drinking one cup of coffee lowered premature death risk by 8 percent, a rate that increased to 16 percent for six to seven daily cups and dropped to 14 percent among people drinking eight or more cups daily.
Perhaps even more surprising, even people who drank decaf coffee benefitted — suggesting that it may not be the caffeine that's boosting life span.
Coffee contains lots of antioxidants, says Brigitte Zeitlin, RD, like polyphenols and hydroxycinnamic acids, which fight disease-causing free radicals, inflammation, premature aging and oxidative stress. And that may help prevent heart disease, Type 2 diabetes and certain cancers.
It's important to keep in mind, however, that the study is observational, meaning it asks people to rely on their memory (and being honest). And it doesn't directly link coffee to life span, so a lot of other factors could be at play.
Zeitlin points out that for the specific mortal diseases the researchers mentioned, genetics play a huge role — and those seem to be unaccounted for. It also doesn't take into account all the other stuff that people ate or drank, which also plays a role in their risk of dying.
Other Health Benefits of Drinking Coffee
In 2015, the growing research in favor of coffee led the U.S. Dietary Guidelines Advisory Committee to suggest that three to five daily cups of coffee can be part of a healthy diet. The World Health Organization (WHO) followed in 2016, updating its recommendations to remove coffee from a list of possible carcinogens and indicate that it might protect against uterine and liver cancer.
A number of studies have linked coffee to reduced risk of:
The biggest benefits, however, are the ones most people are seeking when they pour their morning cup. "The strongest evidence for coffee is that it helps with alertness and cognitive function," says Marisa Moore, RD. "Coffee helps boost blood circulation, which boosts your physical and mental performance." A 2005 British study found that sipping on a cup before exercising helped participants work out harder and longer.
"It does not on its own boost your metabolism or burn fat. Those are myths," says Zeitlin. "Your increased energy at the gym does."
Side Effects of Too Much Coffee
Because caffeine is a stimulant, it can lead to the jitters — feelings of nervousness, restlessness, irritability, fast heartbeat and even muscle tremors — depending on how sensitive you are to it.
Coffee is also acidic, Moore notes, which can cause an upset stomach and lead to acid reflux. And too much can increase your blood pressure and even disrupt your sleep, especially if your last cup comes later in the day.
"I see plenty of clients who use coffee to boost their energy, which causes sleep problems. It's a vicious cycle of relying on caffeine for energy when your body actually needs rest," says Moore.
Some research has shown that loading up on coffee increases the risk of some cancers, including bladder and pancreatic cancer, although Zeitlin says those findings may be due to other stuff in your cup of joe (sugar, cream and sugar substitutes, for instance).
Is Coffee Actually Good for You?
The question we all want to know: Is coffee in moderation a net positive or net negative for your health? "If you're already a coffee drinker, you can feel better about your daily cup of coffee," says Moore. Just don't boost your coffee intake hoping to reap even more benefits without checking with your doctor first.
Zeitlin and Moore both suggest keeping your intake to three to four cups (300 to 400 milligrams daily) to reap the benefits without the negative side effects. The standard eight ounces delivers about 100 milligrams of caffeine, and an espresso has about 63 milligrams of caffeine in a one-ounce shot. Adjust your cup count if your brew is bigger.
Also, skip real and artificial sweeteners, flavoring, whipped cream and fake creamers, which don't do your body any good. Instead, keep it black or add milk or your favorite unsweetened milk substitute.
If you typically down six or more cups a day and don't experience the downsides of coffee, there's not a particular reason to stop — although limiting yourself to five to six cups (500 to 600 milligrams) of coffee a day can help keep your caffeine intake in check.
What Do YOU Think?
Do you drink one or more cups of coffee a day? Do you believe that coffee in moderation is good for your health? Let us know what you think in the comments below!