Diet filled with flavonoid-rich foods such as apples and bananas may help slow cognitive decline, study finds

‘Adding colour to your plate may lower risk of cognitive decline,’ as Tom Batchelor explains

Flavonoids are a group of naturally occurring phytochemicals found in plants and have long been considered to be powerful antioxidants (Getty Images/iStockphoto)

Eating foods such as strawberries, apples and bananas that are rich in flavonoids can help slow cognitive decline, a study found.

Researchers from Harvard University analysed the health records of more than 77,000 American adults, examining a possible link between long-term dietary flavonoids and subjective cognitive decline (SCD) – the self-reported experience of worsening confusion or memory loss.

They found that those who consumed the highest levels of flavonoids were 38 per cent less likely to suffer cognitive decline – with the protection equivalent to being up to four years younger.

Flavonoids are a group of naturally occurring phytochemicals present in plants and have long been considered to be powerful antioxidants.

They are found in a variety of fruits and vegetables including oranges, grapefruits, pears, celery, carrots, sweet potatoes and peppers.

The researchers concluded that higher flavonoid intakes “may help maintain cognitive function”, and recommended “future studies in search of possible therapeutic or preventive strategies for cognitive decline, including the possible effects of specific flavonoids on cognitive function and the effective dosage”.

Lead author Dr Walter Willett, of Harvard University, said: “There is mounting evidence suggesting flavonoids are powerhouses when it comes to preventing your thinking skills from declining as you get older.

”Adding colour to your plate may lower the risk of cognitive decline.

“Our results are exciting because they show making simple changes to your diet could help prevent cognitive decline.”

Those in the highest 20 per cent of flavonoid consumers ate an average of about 600mg daily. The lowest fifth managed roughly 150mg.

About eight strawberries have roughly 180mg, while an apple has about 113mg and a yellow pepper has about 5mg. The same weight in blueberries has about 164mg of anthocyanins.

”The group of highest flavonoid consumers had 20 per cent less risk of self-reported cognitive decline than the people in the lowest group,“ Dr Willett said.

Previous studies attempting to establish the effect of flavonoids on cognitive decline associated with Alzheimer’s disease have been inconclusive.

Commenting on the study, Dr Sara Imarisio, head of research at Alzheimer’s Research UK, said: “Understanding the different factors that affect our dementia risk is vital for finding new ways to reduce the number of people who develop the condition in the future.

“While the researchers found that those eating a diet with high levels of flavonoids were less likely to report memory and thinking problems, we should treat these results with caution.

“The study relied on participants accurately filling out a survey about what they ate, rather than having their food intake monitored.

“What’s more this study didn’t look at dementia, and we can’t know from this research whether a diet high in flavonoids would have any effect in either preventing or delaying the onset of the condition.

“Dementia is caused by a complex mix of age, genetics and lifestyle factors. From this study alone we are unable to untangle diet or a specific food component from other lifestyle factors which contribute to dementia risk.

“While a balanced diet is one way we can help to maintain a healthy brain, the best current evidence points to a number of other lifestyle factors that can also play a role.

“These include not smoking, staying mentally and physically active, drinking within the recommended guidelines and keeping blood pressure and cholesterol in check.”

The study is published in the journal, Neurology.