Regular tea drinkers had a 36.6 per cent lower risk of ischaemic stroke, while drinking tea described as 'burning hot' was associated with a 16 per cent higher risk of vascular disease, a new study in the Journal of Internal Medicine has found.

Drinking tea at least three times a week was linked to an 11.2 per cent lower risk of vascular disease. The findings suggest that how tea is drunk may matter as much as how often.

Researchers followed 485,934 participants in the China Kadoorie Biobank for an average of nine years. During follow-up, 14,863 cases of vascular disease were recorded.

Does Tea Lower Stroke Risk?

Participants reported how often they drank tea, as well as the type, strength and temperature. Regular drinking meant at least three times a week, not necessarily every day.

Cerebrovascular disease risk was 19.1 per cent lower among regular drinkers, the next strongest association after ischaemic stroke. The link was significantly stronger in people with obesity.

Non-smokers who were physically active and drank tea regularly had the lowest estimated risk. The associations were consistent across most demographic groups.

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How Tea May Protect Arteries

Tea contains polyphenols, including flavonoids, which have antioxidant and anti-inflammatory properties. Dr Leana Wen, an emergency physician and clinical associate professor at George Washington University, said these may protect blood vessel linings.

They may also help arteries relax and expand, lowering blood pressure and easing strain on the heart. Some studies suggest tea modestly improves blood pressure and cholesterol.

Black tea showed the most consistent association across types of cardiovascular disease, followed by green tea. Researchers linked its edge to theaflavins, compounds formed in processing with anti-inflammatory and lipid-regulating effects.

Both green and black tea can suit a heart-healthy diet if taken without added sugar. Choosing unsweetened tea over soda or juice drinks also cuts added sugar, aiding weight and metabolic health.

The Burning Hot Tea Warning

Participants who reported drinking tea 'burning hot' had a 16 per cent higher risk of vascular disease, while habitual tea consumption overall was associated with a lower risk. Tea at room temperature, or hot but not scalding, carried significantly lower risk.

The best combination was moderately strong, non-scalding tea. Very hot drinks have also been associated with a greater likelihood of oesophageal cancer, so tea should cool until it can be sipped comfortably.

Temperature was self-reported, so definitions of scalding may vary between people. Those who prefer very hot tea may also differ in diet or lifestyle in ways the researchers could not fully account for.

Limits of the Evidence

Dell Stanford, a senior dietitian at the British Heart Foundation who was not involved, said the study was observational and other diet and lifestyle differences could explain the findings. The results do not prove tea protects the heart.

The lowest estimated risk appeared at six to eight cups a day among weekly drinkers, but this is not a target. Cup size was not standardised, intake was self-reported, and the authors cautioned against reading it as optimal.

A separate case-control study, INTERSTROKE, compared 13,462 people with a first stroke and 13,488 controls from 32 countries. Those with the highest tea intake had 19 per cent lower odds of all stroke and ischaemic stroke.

Caffeine Cautions

Tea also contains caffeine, about 30 to 50mg in an 8oz cup of black tea. The US Food and Drug Administration cites 400mg daily as an amount not usually linked to dangerous effects.

Pregnant people are advised to limit caffeine to 200mg a day. Those with sleep problems, anxiety or palpitations should monitor their total intake.

Non-tea drinkers have no need to start. Well-established ways to protect the heart include regular exercise, not smoking, keeping blood pressure and cholesterol healthy, and eating a nutritious diet.

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