Coffee and Tea Are Shockingly Good at Keeping You Healthy

Both beverages, especially in large amounts, are linked to better health and longer life

Photo: Nathan Dumlao/Unsplash

New research adds a cup or two of good news to a pot of mounting evidence indicating that both coffee and tea — and apparently lots of it — can help people live longer, healthier lives. There’s just one catch: The evidence suggests you’ll want to eat well and exercise, too. Caffeinated drinks won’t make up for copious doughnuts and couch time.

In several past studies, coffee consumption has been linked to a lower risk for type 2 diabetes, cancer, Parkinson’s disease, depression, and Alzheimer’s disease. A study last month tied consumption of several daily cups of coffee to a 16% lower risk of death from prostate cancer. People who drink tea (green or black) have been found to live longer, too, and have lower odds of heart disease and other deadly illnesses.

“There is not yet enough clear evidence to recommend increasing coffee consumption to decrease the risk of heart disease with the same strength and certainty as stopping smoking, losing weight, or exercising.”

Now a study suggests drinking one or more cups of caffeinated coffee per day can reduce the risk of heart failure. The new finding, published February 9 in the American Heart Association’s journal Circulation: Heart Failure, is based on 10 years of data on 21,000 U.S. adults from three separate research projects. Two of the data sets reveal that the risk of heart failure declined between 5% and 12% per cup of coffee compared with drinking none. The third indicated no difference based on drinking just one cup per day, but the risk of heart failure dropped 30% for those who enjoyed two or more on a daily basis.

Some older research had suggested coffee might be bad for the heart. But it often failed to take into account whether coffee drinkers smoked or drank alcohol in excess. A host of newer studies, including this latest one, factor those things in and debunk that notion, says study leader David Kao, MD, assistant professor of cardiology and medical director at the Colorado Center for Personalized Medicine at the University of Colorado School of Medicine. But, Kao adds, there are other, more profound ways to protect your heart.

“There is not yet enough clear evidence to recommend increasing coffee consumption to decrease the risk of heart disease with the same strength and certainty as stopping smoking, losing weight, or exercising,” he says.

Tea, too

Another new study, detailed February 4 in the journal Stroke, analyzed coffee- and tea-drinking habits across more than 18 years among 46,213 people in Japan, ages 40 to 79 at the outset. The findings:

  • For stroke survivors, lots of green tea (at least seven cups a day) lowered their risk of death by 62% compared with people who rarely drank tea and 35% lower for those who drank one to two cups a day.
  • People who’d had heart attacks saw similarly reduced risk of mortality if they consumed tea.
  • People with no history of heart attack or stroke who drank at least one cup of coffee weekly had a 14% lower risk of death compared to people who consumed none.
  • Heart attack survivors who had at least one cup of coffee per day had a 22% lower risk of mortality.

Previous research has linked tea drinking to lower blood pressure and better cholesterol levels and a lower risk of death from cancer, heart disease, and all causes.

About those doughnuts…

The new studies have limitations that confound most diet-related research. For one, they rely on self-reported tea and coffee consumption. Also, while they aim to account for other lifestyle factors, the studies can’t fully decouple hot beverage consumption from each person’s overall diet and exercise habits.

The results, therefore, show correlations, not cause and effect, and they speak not to individual outcomes but to averages across a population.

In fact, in both new studies, the people who drank more coffee or tea tended to have healthier lifestyles, notes Linda Van Horn, PhD, a professor and chief of the Department of Preventive Medicine’s Nutrition Division at the Northwestern University Feinberg School of Medicine. Van Horn, also a member of the American Heart Association’s Nutrition Committee, was not involved in either study.

“These individuals ate more fish, vegetables, and other nutrient-dense foods and were more likely to engage in more walking and exercise,” Van Horn tells Elemental.

Despite study shortcomings, the evidence of benefits from coffee and tea grows ever stronger. It’s thought that molecules called polyphenols and other antioxidants in the beverages quell free radicals. But those positive effects can be diminished if the drinks are loaded up with whipped cream or caramel or the sundry other sugars and fats that make coffee and tea concoctions unrecognizable.

“These beverages contribute polyphenols that are known to have anti-inflammatory benefits, especially when substituted for non-nutritious sugary beverages, which can be healthful,” Van Horn says.

Caffeine vs. decaf

It’s not clear whether caffeine itself is beneficial, but the consensus is that for most adults, caffeine at the very least does not raise the risk of cancers or cardiovascular disease. A 2017 study found both regular and decaf coffee correlated with longer life. The new research led by Kao found “caffeine was at least part of the reason for the apparent benefit from drinking more coffee.”

Children should not consume caffeine, health groups advise. But beyond the known side effects of caffeine — headaches, sleep disruption, even trembling or nervousness for some people — there appears to be little reason for most adults not to enjoy cup after cup of coffee or tea.

“Neither coffee nor tea appear to contribute additional risk among adults who had stroke or cardiovascular-disease events, and indeed, there may be benefits to drinking these beverages,” Van Horn says. “This might be especially true if these beverages are replacing sugary drinks or high fat and high-calorie beverages.”

Explainer of things, independent health and science journalist, author, former editor-in-chief of LiveScience and Space dot com.

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