Should You Drink More Tea for Your Heart After the New China Study?
If you enjoy unsweetened tea, there's good reason to keep it in your day. A new study of nearly half a million Chinese adults found regular drinkers developed heart and blood-vessel disease less often. The evidence doesn't yet support drinking more than you'd naturally choose. The study's more consistent associations for black tea than green, and its lowest-risk point at several cups a day, come from observation and haven't been tested as a recipe. Staying active and not smoking remain the habits with the stronger evidence behind them.
Half a million people, the same direction as before
The study, from the China Kadoorie Biobank and published in October in the Journal of Internal Medicine, followed nearly half a million Chinese adults for an average of about nine years. Habitual tea drinking was associated with about an 11% lower rate of vascular disease.
This extends an established pattern more than it breaks new ground. Earlier analyses of the same cohort linked daily tea to lower rates of ischemic heart disease and of stroke, and a separate Chinese cohort found a similar association with atherosclerotic disease. Because the new paper draws on the same participants as those earlier analyses, it adds preparation details without being an independent confirmation.
What controlled trials show about tea and your arteries
There is some human trial evidence that tea affects blood-vessel function. A 2020 review of short-term randomized trials, lasting up to about six months, found tea didn't significantly lower blood pressure or cholesterol. Both kinds of evidence measure intermediate markers, so neither settles whether years of tea drinking prevent heart attacks or strokes.
The cohort itself has the usual weak points of observational research, and a few specific ones. Tea intake was asked about once, at enrollment, with no standard cup size. An outside expert noted the model wasn't fully adjusted for diet or income, both of which could differ between tea drinkers and non-drinkers. Everyone studied lived in China, where tea habits differ from those in the UK or US. Genetic studies designed to get closer to cause have come out mixed, with one linking genetically predicted tea intake to lower ischemic stroke risk and another finding no evidence of a causal effect on the cardiovascular diseases it examined.
What the black tea, strength and cup findings can support
The new study's novelty lies in how tea was prepared, and these results are the ones most likely to be quoted as instructions. Here is what each one shows and how far it reaches.
| Tea habit | Reported association | What it means for your choice |
|---|---|---|
| Black versus green tea | Black tea showed more consistently inverse associations than green | This doesn't establish that black is better, and earlier Asian studies often found the clearest links with green tea. Either is a reasonable choice. |
| Moderate-strength tea | Moderate strength was linked to lower observed risk | The available summary doesn't define weak, moderate or strong, so there is no brewing recipe to copy. |
| Six to eight cups a day | Modeled lowest-risk point among people who drank tea at least weekly | Cup size wasn't standardized and uncertainty around this point wasn't given in the abstract. Other analyses found different dose patterns, so this isn't a daily target. |
| Burning-hot tea | Linked to higher vascular risk | The abstract gives no temperature cutoff, and cooling tea isn't proven heart protection. A broad review also linked very hot tea to esophageal and gastric cancer. |
The study ran many comparisons, and an expert reviewing it cautioned that the most striking ones, including black versus green and temperature, should be treated as exploratory. If you're tempted to work up to six to eight cups anyway, keep in mind that caffeine from every source adds up, and the amount in your tea varies with the product and preparation.
Where tea ranks next to moving and not smoking
The lowest-risk group in the study were people who drank tea habitually, didn't smoke and were highly active. A combined group like this can't show how much of the difference belongs to the tea.
If you drink unsweetened tea because you like it, this study gives you a well-grounded reason to keep going, and letting it cool a little costs you nothing. The case for prescribing tea, or a particular variety, strength or quota, would be stronger with large, long randomized trials that compare standardized brews and amounts and count heart attacks and strokes; independent cohorts with repeated intake measurements and defined brewing methods could strengthen the observational case. Until then, enjoyment and how well you tolerate its caffeine can guide your tea drinking, and staying active and smoke-free remain parts of prevention you can rely on.