Recent research has come down squarely on the side of caffeinated morning beverages, suggesting that coffee can protect against cancer and type 2 diabetes. Tea has enjoyed a healthy reputation for years as a heart-protector, and a study published in the October issue of British Journal of Nutrition suggests it might even help lower blood pressure.
Researchers were intrigued by the inconclusive link in studies so far regarding blood pressure and tea intake, so they analyzed 25 randomized controlled trials—the gold standard of scientific research—to further explore on the association.
They found that in the short term, tea didn’t seem to make a difference for blood pressure. But long-term tea intake did have a significant impact. After 12 weeks of drinking tea, blood pressure was lower by 2.6 mmHg systolic and 2.2 mmHg diastolic. Green tea had the most significant results, while black tea performed the next best.
Those might not seem like big numbers, but small changes in blood pressure can have a significant impact on health, the study authors write. Reducing systolic blood pressure by 2.6 mmHg “would be expected to reduce stroke risk by 8%, coronary artery disease mortality by 5% and all-cause mortality by 4% at a population level,” they write.
Tea is thought to offer endothelial protection by helping blood vessels relax, allowing blood to flow more freely. It’s a high source of antioxidants that have been linked to better cardiovascular health.
The researchers weren’t able to pinpoint the optimal number of cups to drink to get the benefit, but other studies have shown protective effects at 3-4 daily cups. The researchers said they didn’t see a difference in caffeinated tea vs. decaf.
“These are profound effects and must be considered seriously in terms of the potential for dietary modification to modulate the risk of CVD [cardiovascular disease],” the authors write.
See the 10 Healthiest Cities to Live in America
More Must-Reads from TIME
- Donald Trump Is TIME's 2024 Person of the Year
- Why We Chose Trump as Person of the Year
- Is Intermittent Fasting Good or Bad for You?
- The 100 Must-Read Books of 2024
- The 20 Best Christmas TV Episodes
- Column: If Optimism Feels Ridiculous Now, Try Hope
- The Future of Climate Action Is Trade Policy
- Merle Bombardieri Is Helping People Make the Baby Decision
Write to Mandy Oaklander at mandy.oaklander@time.com