Tea is enjoyed across cultures as a comforting daily beverage, but its potential health effects may depend on more than the type of leaves used. Recent research suggests that drinking frequency, brewing strength and serving temperature could all influence the relationship between tea consumption and cardiovascular health.

A large study published in the Journal of Internal Medicine in October 2026 examined tea-drinking habits among nearly half a million adults in China.

What the Large Study Discovered

Researchers analyzed information from more than 485,000 adults aged 30 to 79. Participants provided details about their tea habits, including how often they drank it, which varieties they preferred, how strongly they brewed it and how hot they liked it.

Over approximately nine years of follow-up, researchers recorded more than 14,800 cases of cardiovascular disease. The analysis found that participants who drank tea at least three days per week had around an 11% lower relative risk of developing vascular disease compared with people who drank it less frequently.

Why Tea Compounds May Support Circulation

Tea contains naturally occurring plant compounds known as polyphenols. A major group within this category is flavonoids, which have attracted scientific attention because of their antioxidant and anti-inflammatory properties. Some research suggests that these compounds may support the endothelium, the thin layer of cells lining blood vessels. This lining helps regulate circulation by controlling how vessels relax and contract.

Healthy endothelial activity is important for maintaining blood pressure and allowing blood to move efficiently throughout the body. Tea polyphenols may also influence processes connected to cholesterol regulation and inflammation. These possible effects offer biological explanations for the associations observed in population studies.

Black Tea and Green Tea: Is There a Difference?

Black and green tea both originate from the same plant, Camellia sinensis. Their main differences come from processing methods, particularly the degree of oxidation experienced by the leaves. Green tea undergoes minimal oxidation, helping preserve certain catechins. Black tea is more extensively oxidized, producing different compounds, including theaflavins and thearubigins.

In the 2026 study, black tea showed more consistent associations with lower cardiovascular risk across several disease categories. Green tea was also associated with potential benefits, although the patterns were less consistent. These findings do not establish black tea as universally superior.

Why Serving Temperature Matters

One of the most notable findings involved people who preferred drinking tea at extremely high temperatures. Participants reporting a burning-hot preference had a 16% higher observed risk of vascular disease compared with those who did not regularly drink tea. By contrast, tea consumed at room temperature or at a comfortably hot temperature was associated with lower risk compared with infrequent tea consumption.

Expert Insight

Dell Stanford, senior dietitian at the British Heart Foundation, commented on the findings for the Science Media Centre. Emphasizing the limitations of observational research, Stanford stated: “This was an observational study and other differences in people’s diets and lifestyles could help explain the findings.”

How Much Tea Is Reasonable?

The study identified the lowest estimated cardiovascular risk among participants consuming approximately six to eight cups daily. However, this figure should not be interpreted as a recommended daily target. The researchers did not use a standardized cup size, and consumption information came from participants' own reports.

Very high tea consumption may also increase caffeine intake. Black tea commonly contains more caffeine than green tea, although the amount varies according to brewing time, serving size and preparation.

Research published in 2026 suggests that regular tea consumption may be associated with better cardiovascular outcomes, with black tea showing particularly consistent associations. However, tea alone cannot guarantee cardiovascular protection. Physical activity, balanced nutrition and appropriate monitoring of blood pressure and cholesterol remain important. The strongest takeaway is to enjoy tea at a comfortable temperature while maintaining healthy habits across everyday life.