Apples, pears & berries rich in flavonoids could help weight management, study finds

A team of researchers in Boston and the UK found consuming foods rich in flavonoids – bioactive compounds in fruit and vegetables – was associated with significantly less weight gain in men and women nationwide over 24 years.

In particular, participants in the Health Professionals Follow Up Study, Nurses’ Health Study and Nurses’ Healthy Study II who consumed foods rich in three flavonoid subclasses – anthocyanins, flavonoid polymers and flavonols – gained 0.16 to 0.23 pounds less per four year intervals for each greater standard deviation of daily intake, according to the study published in The BMJ Jan. 28​​. 

The main sources of anthocyanins recorded in the self-reported diets were blueberries and strawberries, while tea and apples provided the most flavan-3-ols and their polymers. Oranges, orange juice, onions and peppers also are good sources of flavonols, according to the study.

Notably, it doesn’t take much of these foods to impact weight management, according to the study. For example, one half cup of blueberries provides about 121 mg of anthocyanins – or 12 standard deviations, the authors note.

While the magnitude of association is small, any reduction in weight gain offers significant benefits, they add.

“Preventing even small amounts of weight gain could have an important public health impact: gaining 10 lbs (4.5 kg) or more between the ages of 40 and 60 increased the risk of developing diabetes 40-70% and a meta-analysis of 221 studies found a 24-59% increased risk of several cancers,”​ the study says.

The authors acknowledge that the mechanisms to explain the benefits of these fruits and vegetables are unclear. But, fiber content – which can aid in weight management by making people feel full – does not seem to be a contributor, the authors note. They saw the same benefits even when they adjusted for fiber intake.

The study also is notable because it is larger than previous studies with more than 124,000 participants. Likewise, most previous research focused on flavonoids in green tea and this looks at more food sources.

Even though the study is observational – an therefore no definitive conclusions can be made – the results suggest that choosing high flavonoid fruits and vegetables may help with weight control.

“Most Americans consume less than one cup (less than two servings) of fruits and less than two cups of vegetables daily,”​ the authors write. “Beyond increasing intake to current recommendations of two cups of fruit and 2.5 cups of vegetables per day, people may be able to maximize their health benefits by including optimal fruits and vegetables in their daily diets.”​