By Stephen Renberg
MONDAY, Nov. 28, 2022 (HealthDay News) — Eating more berries and drinking tea may help slow mental decline as you age, a new study suggests.
In a study of more than 900 adults, researchers found that foods like these — which contain antioxidant flavonols — offer brain benefits for older adults. Flavonols are found in fruits such as berries, leafy green vegetables, tea, and wine.
For example, people who ate a serving of green leafy vegetables a day slowed their rate of cognitive decline by about 32%, compared to people who didn’t eat any foods containing flavonols, said lead researcher Dr. Thomas Holland, an internship coach. Medicine at Rush University Medical Center in Chicago.
“Flavonols are both anti-inflammatory and antioxidants,” he said. “These foods that contain flavonols destroy free radicals and prevent cell damage. They prevent cell damage in the brain as well as in other organs, such as the heart, vascular system, kidneys, liver, etc.”
The Netherlands is not keen on getting flavonols from dietary supplements. He believes the best way to stock up on flavonols is through the diet.
“You will get a greater variety of nutrients from food,” he said. “I like to keep supplements exactly that way, nutritional supplements. They should complement a healthy diet.”
For the study, Holland’s team collected data on 961 adults, average age 81, who did not have dementia. Over an average of seven years, the participants completed annual questionnaires about their diet and took cognitive and memory tests. The tests involved remembering lists of words, calling out numbers, and putting them in the correct order.
The study shows an association between higher amounts of flavonols and slower cognitive decline, Holland cautioned, but a direct cause-and-effect relationship cannot be proven. Also, people’s memories of what they ate may not be completely accurate.
Researchers found that people who ate the highest amount of flavonols, about 15 milligrams per day (equivalent to 1 cup of dark leafy greens), had the slowest memory decline, compared to those who ate the least amount of flavonols, about 5 milligrams per day. This association remained after adjusting for age, sex, and smoking.
The researchers said the foods that contributed significantly to slowing mental decline included cabbage, beans, tea, spinach, broccoli, tomatoes, apples, tea, wine, oranges, pears, olive oil and tomato sauce.
“Plant foods contain a treasure trove of powerful nutrients that offer significant health benefits,” said Samantha Heller, MD, a clinical nutritionist at NYU Langone Health in New York City.
Flavonoids are just one family of more than 5,000 compounds found in plants. “This family includes a subgroup called flavonols,” she noted.
This study focused on the flavonol content in people’s diets and its relationship to cognitive health, but we don’t sit down and eat a plate of flavonols for breakfast, said Heller, who had no role in the study.
“We eat foods that contain a range of phytonutrients [healthy plant compounds], such as fiber, vitamins, minerals, and phytochemicals, such as flavonols. These phytonutrients work synergistically together as a team, and this is what enhances the health benefits we derive from eating them.”
These elements interact with each other in many biological processes — for example, reducing inflammation, supporting the immune system, protecting and repairing cells, and reducing oxidative stress, Heller said.
She stressed that one component of the diet may not be a magic path to a long and healthy life.
“People in this study who ate a plant-based diet may have seen the greatest cognitive benefits, but this was not evaluated. Research shows that switching to eating more legumes, vegetables, fruits, nuts, and whole grains helps us live longer and healthier,” Heller said.
Holland agreed that flavonols alone would not prevent mental decline. He said the best way to maintain physical and mental health, includes a healthy lifestyle integrated with a varied diet of fruits and vegetables, physical activity and cognitive training – challenging yourself every day by learning something new.
“Also, sleep and stress reduction will both be beneficial to overall health,” Holland said. “It’s never too early or too late to start making healthy changes.”
The report was published online November 22 in the journal Neurology.
For more on flavonols, see the American Heart Association.
SOURCES: Thomas Holland, MD, instructor, Department of Internal Medicine, Rush University Medical Center, Chicago; Samantha Heller, MS, RD, CDN, Senior Clinical Dietitian, NYU Langone Health, NYC; NeurologyNovember 22, 2022, online