Seven to eight cups of coffee, tea, water can extend a person’s life.
A large population study from the United Kingdom has brought renewed attention to the everyday drinks that fill most people’s cups. Researchers working with the UK Biobank followed more than 182,000 adults for over a decade to see how coffee, tea, and water intake related to long-term health and death risk. Their analysis, published in the British Journal of Nutrition, concluded that those who drank seven to eight beverages a day had a longer lifespan those who drank much less. The benefits were strongest for people who consumed a balanced mix of coffee and tea, rather than relying heavily on just one.
The study team found that the most favorable ratio was about two parts coffee to three parts tea. This combination was tied to the lowest risk of death and longest lifespan from all causes, as well as lower rates of cancer, heart disease, respiratory illness, and digestive disease. For example, the risk of dying from respiratory disease was reduced by more than 70 percent among those who followed this balanced pattern compared to those who did not. Digestive disease deaths also dropped by more than 60 percent in this group.
These results add weight to years of smaller studies suggesting that moderate coffee and tea drinking supports better health outcomes and a longer lifespan. Both drinks are rich in bioactive compounds that affect inflammation, metabolism, and vascular health. Water, of course, remains essential to human survival, but the findings indicate that combining plain water with coffee and tea in reasonable amounts may deliver stronger protection than water alone. Importantly, the study showed that drinking fewer than four cups of any beverage per day left people at higher risk, suggesting that hydration in general remains the first step toward better health.
The research also stressed limits. Drinking more than nine beverages a day, particularly when extra cups were coffee or tea replacing water, appeared to raise the risk of cardiovascular death. Caffeine can have dehydrating and blood pressure–raising effects when consumed in excess, which may explain this finding. The takeaway appears to be that while hydration and a variety of drinks can extend life, more is not always better.
The work relied on detailed dietary recalls collected between 2009 and 2012. Participants reported not only how much they drank but also what types of beverages replaced one another during the day. The analysis used a framework that compared the health effects of swapping one drink for another, allowing researchers to show how replacing water with coffee or tea changed risk profiles. This design gave clearer answers than earlier studies that simply tracked the number of cups consumed without considering what was being replaced.
Over an average of 13 years of follow-up, researchers adjusted for many other factors that could influence outcomes, including age, sex, smoking, medical history, and overall diet. Even with these controls, the patterns linking moderate, mixed beverage intake with a longer lifespan remained strong. Still, the study authors acknowledged limits. Data were self-reported, leaving room for error, and the preparation methods of the drinks—whether sweetened, milk-based, or plain—were not captured in detail.
Even with these caveats, the findings carry important implications for everyday habits. They suggest that hydration is best approached as a balance rather than a one-size-fits-all prescription. Seven to eight cups spread across water, coffee, and tea each day may represent a sweet spot where hydration, bioactive compounds, and moderate caffeine intake work together to protect health. Going below that leaves the body underhydrated, while going far above may stress the heart.
The study does not prove cause and effect, but it strengthens the case for moderation and variety in daily drinking choices. Coffee and tea continue to be two of the most widely consumed beverages in the world, and when paired with enough water, they may offer more than just comfort or a caffeine boost. They may help extend life itself.
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Study finds 7 to 8 cups a day of coffee, tea, and water tied to longer life
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