A Frontiers in Nutrition study of more than 25,000 adults with coronary heart disease found that drinking about three cups of tea daily was linked to a 17 percent lower risk of major cardiovascular events.
By yourNEWS Media Newsroom
Drinking about three cups of tea per day was associated with a lower risk of serious cardiovascular complications among adults with established coronary heart disease, according to a new study published in Frontiers in Nutrition.
The study analyzed more than 25,000 adults with coronary heart disease who were enrolled in the UK Biobank and followed for an average of 13.9 years. Researchers examined whether tea consumption was associated with the risk of major adverse cardiovascular events, known as MACE, a measure that included nonfatal heart attack, nonfatal stroke and cardiovascular death.
Researchers found that participants who reported drinking about three cups of tea daily had a 17 percent lower risk of MACE compared with participants who did not drink tea. The authors said the findings suggest that habitual tea intake at that level may offer a practical dietary strategy for reducing cardiovascular risk in people already diagnosed with coronary heart disease.
The study also examined whether two biomarkers changed the relationship between tea drinking and cardiovascular outcomes. Researchers looked at C-reactive protein, or CRP, a marker of systemic inflammation, and lipoprotein(a), or Lp(a), a cardiovascular risk factor that is largely genetically determined.
The association between tea and reduced cardiovascular risk appeared strongest among participants who had higher baseline inflammation, based on CRP levels, and among those with lower Lp(a) levels. The authors said inflammation may be one possible pathway through which tea intake is linked to improved cardiovascular outcomes.
The study relied on UK Biobank data and grouped participants by self-reported tea consumption, including those who drank no tea and those who consumed different daily amounts. Researchers adjusted their analysis for several potential confounding factors, including age, sex, smoking status, body mass index, physical activity and medication use.
The relationship between tea intake and cardiovascular outcomes appeared nonlinear. The strongest reduction in risk was observed at about three cups per day. Drinking four or more cups daily was still associated with benefit, but the researchers said higher consumption did not appear to add further protection beyond the three-cup level.
The findings add to earlier research on tea compounds and heart health. Previous studies have suggested that black tea may reduce C-reactive protein levels in people susceptible to cardiovascular disease, according to research by Theeshan Bahorun and colleagues published in Toxicology. Other research has linked tea flavonoids, including catechins and flavonols, to endothelial support and reduced oxidative stress, according to a report in the Journal of the Science of Food and Agriculture.
The current study did not distinguish between tea types. Green tea has been studied separately for its potential cardiovascular effects because it contains catechins, including epigallocatechin gallate, or EGCG. Prior research has suggested that green tea catechins may support endothelial and vascular function in both animals and humans, according to a review in the book Oxidative Stress and Inflammation in Health.
Flavan-3-ols, compounds found in tea, dark chocolate, apples and grapes, have also been associated in prior research with lower blood pressure and improved blood vessel function, according to a report from NaturalNews.com.
The authors cautioned that the study was observational and does not prove that tea directly caused the lower cardiovascular risk. They also noted that lifestyle factors not fully captured in the analysis could have influenced the results. Because tea intake was self-reported, the data could also include measurement errors.
Researchers said more studies are needed to determine the biological mechanisms involved and whether the findings differ by tea variety, preparation method or caffeine content.
The authors emphasized that tea should not replace prescribed medical treatment for coronary heart disease. Instead, they described moderate tea consumption as a possible dietary addition for patients who already follow medical guidance and treatment plans.
For people who increase tea consumption, caffeinated teas such as green, black and oolong may be better consumed earlier in the day to avoid sleep disruption, according to the report. Herbal teas, which do not come from the Camellia sinensis plant, may be an option later in the day for those avoiding caffeine.
Tea remains one of the world’s most widely consumed beverages, and the new findings add to ongoing research into whether regular tea consumption may support cardiovascular health in high-risk patients.
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