A Seven-Year Study
The Rush Memory and Aging Project study lasted nearly seven years. Researchers studied 961 community-dwelling Chicagoans aged 60 to 100 years, with an average age of 81.
The diet of each participant was evaluated through a questionnaire that analyzed their flavonol intake. At the same time, their cognitive performance was tested each year with a set of 19 different tests.
Dr. Thomas Holland, MD, MS, an assistant professor in the Section of Community and Nutritional Epi and the Division of Translational and Precision Medicine at the Rush Institute for Healthy Aging in Chicago, Illinois, led the study.
Why Was the Study Performed?
Inspired by his late grandmother, who had Alzheimer’s Disease for 10 years, Dr. Holland wanted to determine if there was a way to delay or prevent cognitive decline through healthy behaviors.
What he found is that physical activity, sleep, and, most of all, what we eat definitely matters in terms of brain health.
“It’s never too early or never too late to get into these lifestyle modifications,” Dr. Holland said in a recent interview. “Something as simple as eating more fruits and vegetables and drinking more tea is an easy way for people to take an active role in maintaining their brain health.”
Which Foods Have High
Amounts of Flavonols?
Fruits and vegetables high in flavonols include:
- Dark leafy vegetables, which include kale, spinach, arugula, Romaine lettuce, and broccoli.
- Olives and Olive Oil
Plants contain thousands of phytochemicals scientists are studying for health benefits. Many vitamins are phytochemicals, and they could consider flavonols to be important micronutrients one day.
What Are The Main Flavonols?
The four main flavonols include:
Researchers have found firm evidence that quercetin may help reduce incidences of some forms of cancer. Quercetin is found most abundantly in onions and, to a lesser degree, in broccoli, kale, spinach, strawberries and blueberries, and tea.
Kaempferol also inhibits cancer cells and is found in many of the same foods and tea as quercetin. We can also find this flavonol in certain herbs such as parsley, dill, chives, watercress, elderberry, and stinging nettle.
The flavonol myricetin has shown promise in its ability to help normalize blood sugar within the body. Foods containing myricetin include spinach, blueberries, strawberries, black currants, walnuts, other nuts, honey, and black or green teas.
Isorhamnetin, a flavonol that possesses several antioxidants that may help prevent tumors, scientists believe it may also help protect against cardiovascular and neurovascular diseases. Isorhamnetin can be found in abundance in olives and olive oil, wine, tomatoes and tomato sauce, and pears.
Findings from the Rush
Memory and Aging Project Study
Dr. Holland and his team of researchers looked at the flavonol intake of the participants. The lowest intake of dietary flavonols was approximately 5 milligrams per day, while the highest intake of dietary flavonols was approximately 15 milligrams per day. This is about the amount of one cup of leafy green vegetables.
The study found that kaempferol and quercetin had the most notable impact to reduce the rate of cognitive decline. Study participants who consumed foods with higher levels of kaempferol showed a decrease of 0.4 units per decade compared to those who ate fewer kaempferol-rich foods.
The mean intake of the study’s participants was 9.6 milligrams per day. The average intake of flavonols in the diet in the United States is approximately 16 -20 milligrams per day, but not everyone likes or even consumes fruit and vegetables.
The research team adjusted their data for age, sex, education, physical activity, smoking, and other factors and then looked at test results, including global cognition, episodic memory, semantic memory, speed of perception, and working memory each year.
The research team believes that there is an association with the reduction of cognitive decline in participants who consumed more foods rich in flavonols, but did not go as far as saying flavonol consumption directly slows cognitive decline. They need more research to make that claim.
From the Researchers
Consuming fruits and vegetables can improve our overall good health. The researchers believe that having your plate be as colorful as possible is important. A colorful plate maximizes the number and amount of flavonols in your diet.
“A beige plate is not ideal,” Dr. Holland advises. “Consumption of different fruits and vegetables guarantees a diverse intake of quality and quantity of nutrients and bioactives.”
Getting More Flavonols
Into Your Life With Tea
According to Dr. Holland, the Rush study participants mainly used black tea. Green and white teas can also provide flavonols kaempferol, quercetin, and myricetin. He recommends that when brewing tea, let the tea steep a little longer to get more flavonols in each cup.
While eating more fruits and vegetables and drinking a few cups of tea each day is no guarantee of lasting cognitive health, we are certainly excited about the findings of Dr. Holland and his team at the Rush Institute. With more research, humans may find the right dietary and tea combinations to slow our cognitive decline.
Disclaimer: The Statements made on this blog have not been evaluated by the U.S. Food and Drug Administration.
Please note that all information provided on this website is not intended to recommend, diagnose, treat, cure, or prevent any medical condition or to replace the advice of a doctor or other qualified healthcare professional.
Holland, Thomas Monroe, Puja Agarwal, Yamin Wang, Klodian Dhana, Sue E. Leurgans, Kyla Shea, Sarah L Booth, Kumar Rajan, Julie A. Schneider, and Lisa L. Barnes. “Association of Dietary Intake of Flavonols with Changes in Global Cognition and Several Cognitive Abilities.” Neurology. Wolters Kluwer Health, Inc. on Behalf of the American Academy of Neurology, 22 Nov. 2022. Web. 29 Dec. 2022.
LaMotte, Sandee. “Slow Cognitive Decline with Flavonols, Study Says.” CNN. Cable News Network, 29 Nov. 2022. Web. 29 Dec. 2022.
“Antioxidants: In Depth.” National Center for Complementary and Integrative Health. U.S. Department of Health and Human Services. Web. 29 Dec. 2022.
Sayed, Mobeen, MD. “Dr. Thomas Holland Discusses the Flavonol and Cognitive Decline Study.” YouTube. Dr. Been Medical Lectures, 14 Dec. 2022. Web. 29 Dec. 2022.