Tea May Be Good for Your Heart, but Temperature Matters, New Study Suggests

Researchers followed nearly half a million adults for about nine years, and the results hold good news for regular tea drinkers, with one important catch. Here’s what to know before you pour your next cup.

Tea is often associated with wellness and good health, even a healthier heart. But new research suggests it’s not just a matter of drinking it. How you drink it matters, too.

A study published on October 21 in the Journal of Internal Medicine found that while regular tea drinkers had a lower risk of cardiovascular disease, drinking tea “burning hot” was linked to a higher risk.

What the Study Found

Researchers analyzed data from more than 485,000 adults in China, ages 30 to 79. The subjects were asked to detail how often they drank their tea, what type they preferred, how strong they brewed it, and how hot they drank it. Over an average of about nine years, the researchers recorded more than 14,800 cases of conditions like heart attacks and strokes.

The study found that people who drank tea at least three days a week had about an 11% lower risk of cardiovascular disease than those who drank it less often, even after accounting for factors like age, smoking, and physical activity, according to CNN wellness expert Dr. Leana Wen.

But one significant finding of the study had to do with temperature. People who said they drank their tea “burning hot” had a 16% higher risk compared with those who didn’t drink tea regularly.

Meanwhile, those who drank it hot, but not scalding, or at room temperature had a significantly lower risk. Wen notes a limitation to this, as “burning hot” is subjective, and what one person may deem scalding may not be the same for others.

The study also found that moderate-strength tea was linked to a lower risk. Black tea was also linked to a lower risk across more types of cardiovascular disease than green tea, though both showed benefits.

Why Tea May Help

So what makes tea healthy? It contains plant compounds called polyphenols, which have antioxidant and anti-inflammatory properties. According to Wen, they may help protect blood vessels and help arteries relax, which can lower blood pressure.

Choosing unsweetened tea instead of soda or other sugary drinks can also help cut down on added sugar.

How Much is Enough?

In the study, the lowest risk recorded was at about six to eight cups a day, but the authors warned that this is not a recommendation.

Northwestern Medicine says one to four cups a day is the recommended range for most adults, allowing you to enjoy tea’s benefits without too much caffeine.

Meanwhile, the FDA cites 400 milligrams of caffeine a day as an amount generally not linked to harmful effects, though pregnant people are advised to limit caffeine to 200 milligrams a day.

Tips for a Healthier Cup

Wen recommends letting tea cool until you can sip it comfortably, noting that very hot drinks have also been linked to a higher risk of esophageal cancer. She also suggests drinking it without added sugar and watching your total caffeine intake.

And if you don’t drink tea, there’s no need to start. As Wen points out, exercising, not smoking, and eating a healthy diet are all proven ways to protect your heart.