Oranges, lemons, and other citrus fruits are high in flavonoids, the compounds that give many plants their colors and flavors. A new study says a diet high in flavonoids may lower your risk of cognitive decline as you age.
The study was published in July 2021 in Neurology®, the medical journal of the American Academy of Neurology.
- The study followed 49,493 women (average age of 48) and 27,842 men (average age of 51) for 20 years.
- Participants completed several questionnaires about their diets, and completed two assessments designed to catch the early signs of memory problems.
In studying several types of flavonoids, researchers found that flavones and anthocyanins may have the most significant impact when it comes to protecting against cognitive decline.
The best news?
- Just a half serving per day may result in up to a 20 percent reduction of risk.
Previous research studies have pointed to the possibility that cognitive decline in old age comes as a result of a lack of antioxidant activity. Flavonoids in general are known to have a significant antioxidant effect.
“There is mounting evidence suggesting flavonoids are powerhouses when it comes to preventing your thinking skills from declining as you get older,” said Walter Willett, MD, DrPH, of Harvard University, a study author. “Our results are exciting because they show that making simple changes to your diet could help prevent cognitive decline.”
- Consumption ranged from about 600 mg of flavonoids per day for the highest 20 percent, and about 150 mg per day for the lowest 20 percent.
- The group with the highest intake of flavonoids reported a 20 percent lower level of cognitive decline than the group with the lowest consumption.
That figure is based on flavonoid consumption overall. When they looked into specific flavonoids, they found some differences.
Flavones had the strongest effect, associated with a 38 percent reduction in risk of cognitive decline—the equivalent of being four years younger.
Flavones are highest in yellow and orange fruits and vegetables, and other plant-based foods such as:
- Citrus (bergamot, mandarin, orange)
- Teas (chamomile, rooibos, black, green, oolong)
- Herbs (peppermint, oregano, rosemary, sage)
- Vegetables (parsley, celery, artichoke)
Anthocyanins were associated with a 24 percent risk reduction.
- Blood oranges contain anthocyanins, which give them their rich color.
- Moro blood oranges have the highest concentration of anthocyanins of all blood oranges.
“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.”