Flavonoid-rich foods like tea and dark chocolate may prolong life, study finds

Consuming flavonoid-rich foods such as tea, berries, dark chocolate and even red wine could help people live longer, according to an international study published this week in Nature Food.

Researchers from Queen’s University Belfast, Edith Cowan University in Perth, Medical University of Vienna and Universitat Wien tracked the diets of over 120,000 adults aged 40 to 70 for more than a decade. They found that individuals who consumed a wide variety of flavonoid-rich foods had significantly lower risks of major health conditions, including type 2 diabetes, cardiovascular disease, cancer and neurological disorders, compared to those with less diverse intake.

“Flavonoid intakes of around 500 mg a day was associated with a 16 percent lower risk of all-cause mortality, as well as a ~10 percent lower risk of CVD, type 2 diabetes, and respiratory disease,” said Dr Benjamin Parmenter, ECU Research Fellow and co-lead author. “That’s roughly the amount of flavonoids that you would consume in two cups of tea.”

Diversity over quantity

Crucially, the study found that the diversity of flavonoid-rich foods mattered more than sheer quantity. “Those who consumed the widest diversity of flavonoids had an even lower risk of these diseases, even when consuming the same total amount,” Dr Parmenter added.

Flavonoids are natural compounds found in many plant-based foods and drinks, including tea, apples, oranges, grapes, berries, red wine and dark chocolate.

“We have known for some time that higher intakes of dietary flavonoids can reduce the risk of developing heart disease, type 2 diabetes and neurological conditions like Parkinson’s,” said Professor Aedín Cassidy, from the Co-Centre for Sustainable Food Systems and Institute for Global Food Security at Queen’s University. “This study is significant as the results indicate that consuming a higher quantity and wider diversity has the potential to lead to a greater reduction in ill health than just a single source.”

Eat the rainbow

The findings offer scientific backing to common dietary advice to “eat the rainbow”.

Professor Tilman Kuhn, another co-lead author, commented: “The importance of diversity of flavonoid intake has never been investigated until now, so our study is very significant as the findings align with popular claims that eating colourful foods are invaluable to maintain good health. Eating fruits and vegetables in a variety of colours, including those rich in flavonoids, means you’re more likely to get the vitamins and nutrients you need to sustain a healthier lifestyle.”

The results coincide with the release of the world’s first dietary guidelines for flavonoids in 2022, which recommend not only increasing consumption, but also maximising variety.

Professor Cassidy concluded: “The results provide a clear public health message, suggesting that simple and achievable dietary swaps – such as drinking more tea and eating more berries and apples – can help increase the variety and intake of flavonoid-rich food, and potentially improve health in the long term.”