Black tea and berries could contribute to healthier ageing, research shows

Regular consumption of black tea, berries, citrus fruits and apples may help support healthier ageing, according to a major new international study.

Researchers from Queen’s University Belfast, Edith Cowan University (ECU) in Australia, and Harvard University have found that diets rich in flavonoids – natural compounds found in certain plant-based foods – are linked to a lower risk of several factors associated with unhealthy ageing.

These include frailty, physical impairment and mental health issues.

The study, which followed over 86,000 participants (62,743 women and 23,687 men) for up to 24 years, suggests that simple dietary changes could significantly impact ageing outcomes, particularly among women.

“Flavonoids are well known for reducing oxidative stress and inflammation, supporting blood vessel health, and even helping to maintain skeletal muscle mass – all of which are important for preventing frailty and maintaining physical function and mental health as we age,” said senior author Professor Aedin Cassidy from the School of Biological Sciences and Institute for Global Food Security at Queen’s University Belfast.

Professor Cassidy explained that foods such as berries, apples, red wine, oranges and tea – all high in flavonoids – could be valuable in promoting better ageing outcomes.

“Regularly consuming flavonoid-rich foods… could support healthier aging by reducing the risk of frailty, physical decline, and poor mental health,” she added.

While both men and women benefited from higher flavonoid intake, the study found that women experienced stronger associations between these foods and health outcomes.

Women with the highest flavonoid intakes were found to have a 15% lower risk of frailty, a 12% lower risk of impaired physical function, and a 12% lower risk of poor mental health compared to those with the lowest intake levels.

The researchers cautioned, however, that these differences might not indicate a biological distinction between the sexes.

“The stronger associations observed in women may be due to differences in follow-up time between the two cohorts rather than true sex-specific effects, which remain underexplored in existing research,” Professor Cassidy noted.

Dr Nicola Bondonno, Adjunct Lecturer at ECU, highlighted the broader implications of the findings.

“The goal of medical research is not just to help people live longer but to ensure they stay healthy for as long as possible,” she said.

“We know from previous research that people who have a higher flavonoid intake tend to live longer, and they are also less likely to get any of the major chronic diseases such as dementia, diabetes or heart disease. Our research shows that people who consume more flavonoids tend to age better.”

The findings also revealed a dose-related effect. According to Professor Eric Rimm from Harvard University:

“We found that participants who increased their intake of flavonoid-rich food by three servings a day, had a 6% to 11% lower risk across all three of the ageing outcomes in females, and a 15% lower risk of poor mental health in males.”

He concluded: “Overall, these findings underscore the potential for simple dietary modifications to impact overall quality of life and contribute to the optimisation of healthy aging.”

This study adds to a growing body of evidence supporting the role of nutrition in ageing well, particularly through the inclusion of plant-based, flavonoid-rich foods in the daily diet.