Washington | Eating fruits and vegetables that contain high levels of flavonoids such as apples, pears, berries and radishes may help prevent weight gain, a new study has found. Researchers from Harvard University and the University of East Anglia (UEA) examined the association between the dietary intake of seven flavonoid subclasses and weight change in a study of 124,086 men and women based across the US over 24 years. We found that an increased consumption of most flavonoids were associated with weight maintenance, and even a modest weight loss.
The results were found to be consistent across men and women, and different ages, said Professor Aedin Cassidy, from UEA’s Norwich Medical School. Dietary flavonoids are natural compounds found in fruits and vegetables. These have been linked to weight loss, but most studies have looked at a particular flavonoid found in green tea, and have mostly been limited to small samples. The study tracked participants who were part of three prospective cohort studies – the Health Professionals Follow Up Study, Nurses’ Health Study, and Nurses’ Health Study II.
Participants self-reported their weight, lifestyle habits, and any recently diagnosed diseases via questionnaire every two years, between 1986 and 2011. In addition, they self reported their diet every four years. Findings showed that increased consumption of flavonoid subclasses was associated with less weight gain. The greatest association was found for anthocyanins, flavonoid polymers, and flavonols – each greater standard deviation of daily intake was associated with 0.07 to 0.10 kg less weight gained over four year intervals.
Blueberries and strawberries were the main source of anthocyanins, and flavan-3-ols and their polymers were mainly derived from tea and apples. Orange juice and oranges were the main sources of flavanone and flavones, and tea and onions were the main sources of flavonols. This is the first study to examine the associations between consumption of seven flavonoid subclasses and weight gain in a large sample size.
Losing or preventing even small amounts of weight can reduce risk of diabetes, cancer, hypertension and cardiovascular disease. The results can provide guidance on which fruits and vegetables to choose for preventing weight gain, researchers said. People may be able to maximise the health benefits of eating fruit and vegetables by choosing those with high levels of flavonoids, such as apples, pears and berries, they said.