Study: Colorful diet cuts risk of cognitive decline 20%

A diet packed with flavonoid-rich fruits and vegetables may reduce risk of cognitive decline by 20%, according to a recent study (Neurol. 2021;97[10]:e1041-e1056). 

Flavonoids are phenolic compounds commonly found in fruits and vegetables, as well as tea, wine and grains. The compounds, which are responsible for the vibrant colorings of fruits and vegetables, are well known for their health benefits, including antioxidant and anti-inflammatory effects.  

Research shows the powerful effects of flavonoids can be obtained by eating the foods that contain them. Eating flavonoid-rich foods like cranberries and chocolate, for example, may provide health benefits such as improved mood, brain function and immunity.  

The present study, published in Neurology, credited long-term intake of flavonoid-packed fruits and vegetables including strawberries, oranges, grapefruits, citrus juices, apples, pears, celery, peppers and bananas with significantly lower odds of subjective cognitive decline (SCD). 

SCD is a self-observed decline in cognitive function that’s considered one of the earliest noticeable symptoms of dementia and Alzheimer’s disease—a disease that plagues about 6 million Americans, according to the Alzheimer’s Association. Common symptoms of SCD include worsening or more frequent memory loss and confusion, according to the Centers for Disease Control and Prevention (CDC).  

CDC reported 1 in 9 adults in the United States are dealing with SCD.   

For the study, researchers evaluated the connection between dietary flavonoids and SCD in 49,493 women from the Nurses' Health Study (NHS, 1984-2006) and 27,842 men from the Health Professionals Follow-Up Study (HPFS, 1986-2002). Using data collected from semiquantitative food frequency questionnaires (SFFQs) that were administered to participants of both NHS and HPFS, researchers determined the participants’ long-term average dietary intake.  

To assess SCD, participants were asked questions such as: "Do you have more trouble than usual remembering recent events?" and "Do you have more trouble than usual remembering a short list of items?" SCD was assessed in NHS and HPFS participants twice throughout the study. 

After adjusting for age, total energy intake and dietary factors, results showed people who consumed the most flavonoids each day—about 600 mg of flavonoids—were 20% less likely to report SCD than the people who ate the least amount of flavonoids each day—about 150 mg.  

Flavones, found in high amounts in some teas and herbs, were most strongly associated with decreased risk, representing a 38% reduction in risk of cognitive decline, while anthocyanins were associated with a 24% reduction in risk of cognitive decline. Flavanones were also strongly associated with decreased risk. 

Rachel Adams joined Informa’s Health & Nutrition Network in 2013. Her career in the natural products industry started with a food and beverage focus before transitioning into her role as managing editor of Natural Products INSIDER, where she covered the dietary supplement industry. Adams left Informa Markets in 2019.