Celebrities have to contend with fame's fickle nature. George Clooney once declared, "I'm the flavor of the month." Kiefer Sutherland, star of the series "24," struggled when his flavor lost favor: "When I wasn't the flavor of the week or month or day, those were hard times."

Vegetables face a similar challenge: Their acclaim as "flavonols of the month" comes and goes.

Cauliflower mashed potatoes, tofurkey, kale chips — all contain health-promoting flavonols. But even if you ate them a couple of times, chances are they aren't on your menu regularly.

That's a shame, because flavonols — a group of phytochemicals found in fruit and vegetable pigments, which have anti-inflammatory and antimicrobial power — also protect you from cognition problems.

A 2020 study in the journal Neurology suggests that these nutrients may protect against Alzheimer's disease. For example, one type of flavonol called kaempferol, which is found in spinach and kale, reduced the risk of Alzheimer's by 50% in older people over the course of 14 years.

A follow-up study in Neurology now offers more insights into the power of flavonols. Participants (around age 81) who ate the most flavonols saw the least decline in cognition. The top food contributors for various types of flavonols were:

• Kale, beans, tea, spinach, and broccoli for kaempferol — which was most effective in protecting cognition

• Tomatoes, kale, apples. and tea for quercetin — which also was very protective

• Wine, oranges, tomatoes/tomato sauce, pears, and olive oil for other healthful flavonols