Flavonoids May Reduce Risk of Subjective Cognitive Decline

A study published in Neurology suggests the risk of cognitive decline may be lowered by as much as 20% with a diet rich in flavonoids. Foods that are high in flavonoids include strawberries, oranges, peppers, and apples. Flavones and anthocyanins may have the most protective effect. 

Data for this study came from 49,493 women in the Nurses’ Health Study (NHS) (1984-2006) and 27,842 men from the Health Professionals Follow-up Study (HPFS) (1986-2002). Dietary intake was assessed with repeated food frequency surveys (7 in the NHS and % in the HPFS) that were taken throughout the study periods. Subjective cognitive decline was assessed in 2008 and 2012 for the HPFS and 2021 and 2014 for the NHS. 

After adjusting for age and total caloric intake, an association with flavonoids and subjective cognitive decline was seen. The strongest associations were seen with flavones (odds ratio [OR]=0.62; 95% CI: 0.57, 0.68), flavanones (OR: 0.64; 95% CI: 0.58, 0.68), and anthocyanins (OR: 0.76; 95% CI: 0.72, 0.84). Those with the highest 20% of flavonoid intake consumed an average of 600 mg in their daily diets. Individuals who consumed the least flavonoids had about 150 mg in their daily diet.
 
“There is mounting evidence suggesting flavonoids are powerhouses when it comes to preventing your thinking skills from declining as you get older,” said study author Walter Willett, MD, DrPH, of Harvard University in Boston, Mass. “Our results are exciting because they show that making simple changes to your diet could help prevent cognitive decline.”
 
Researchers also looked at individual flavonoids. Flavones had the strongest protective qualities and were associated with a 38% reduction in risk of cognitive decline. Peppers have about 5 mg of flavones per 100 gram serving. Anthocyanins were associated with a 24% reduced risk of cognitive decline. Blueberries have 164 mg of anthocyanins per 100 gram serving. 

“The people in our study who did the best over time ate an average of at least half a serving per day of foods like orange juice, oranges, peppers, celery, grapefruits, grapefruit juice, apples and pears,” Willett said. “While it is possible other phytochemicals are at work here, a colorful diet rich in flavonoids—and specifically flavones and anthocyanins—seems to be a good bet for promoting long-term brain health. And it’s never too late to start, because we saw those protective relationships whether people were consuming the flavonoids in their diet 20 years ago, or if they started incorporating them more recently.”