Odd couples — from TV's Felix (Tony Randall) and Oscar (Jack Klugman) to the 1968 movie with Jack Lemmon (as Felix) and Walter Matthau (as Oscar) — are fan favorites. And we have another favorite odd couple to introduce you to: kombucha (a fizzy, fermented tea) and berries, especially blackberries.

These two foods are loaded with flavonoids, nutrients that are anti-inflammatory, anticancer, and antiviral and help protect heart and nerve health.

Now a study in JAMA Network Open reveals that especially for people with high blood pressure and depression, flavonoids lower the risk of dementia.

Kombucha plus berries are notably beneficial for those with a genetic predisposition to dementia too.

Other flavonoid-loaded foods that are protective of your cognitive powers include blueberries and strawberries (half a serving daily), black coffee, and green or black tea (five daily servings).

And eating a serving of several flavonoid-rich foods and beverages in a day increases their protective ability. For example, doing that will double the 14% reduction in dementia risk that comes from drinking four cups of tea daily.

Don't like kombucha? Another new study found that fermenting apple juice for 10 days at room temperature loads it up with more flavonoids than the same amount of kombucha.