Depression is the leading cause of disability worldwide, according to the World Health Organization
And, although treatments exist for it, many people do not respond fully to treatment.
Prevention of depression has the potential to improve the health and quality of life of millions of people.
Diet is one way to address depression risk, and recent research has shown the potential of dietary flavonoids to reduce risk of the condition.
Flavonoids are compounds in plant foods that have been shown to have effects that may interrupt the pathophysiology of depression — including by combating neuroinflammation and neuronal cell death.
In addition, some flavonoids seem to improve blood flow, and that may help prevent age-related depression, which is influenced by vascular health.
A study published in 2016 in the American Journal of Clinical Nutrition looked at whether long-term dietary intake of the different subclasses of flavonoids (flavonols, flavones, flavanones, anthocyanins, flavan-3-ols, polymeric flavonoids, proanthocyanidins) were related to depression incidence.
They also examined the connection between specific flavonoid-rich foods and depression risk.
Among the more than 80,000 women followed for this study, approximately 10,000 cases of depression were noted at the 10-year follow-up.
Analysing food frequency questionnaires and other data, the researchers found inverse associations between depression risk and flavonol, flavone and flavanone intake.
In addition, the women who consumed more citrus fruits or juices had a lower incidence of depression.
In older women (65 years or older at baseline), all subclasses of flavonoids except flavan-3-ols were associated with significantly lower risk of depression. The strongest associations were seen with flavones (good dietary sources include oranges, apples, celery, etc.) and proanthocyanidins (apples, chocolate, grapes, etc).
The researchers concluded that, although further studies are needed to confirm these associations, higher flavonoid intake may be associated with reduced risk of developing depression, particularly later in life.