Are Flavonols Good for My Brain?

Researchers found that total flavonol intake was linked to a lower decline in global cognition, according to Thomas Monroe Holland, MD, MS, of Rush University Medical Center in Chicago, and co-authors.

MedPage Today’s recent article entitled “Flavonols Linked to Slower Cognitive Decline” says that slower declines in episodic, semantic and working memory also were tied to overall flavonol intake. Associations were independent of cardiovascular conditions and lifestyle factors, the researchers reported in the medical journal, Neurology.

The findings suggest specific diet choices may result in a slower rate of cognitive decline. "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," Holland said in a statement.

Flavonols are a type of flavonoid, a group of phytochemicals found in plant pigments. Earlier research has shown that high flavonol intake was connected to lower risk of Alzheimer's dementia.

The mechanisms behind these relationships aren't fully understood, the researchers acknowledged. However, the anti-inflammatory features of flavonols may lessen the amplitude or duration of neuroinflammation, Holland and his team suggested. The antioxidant characteristics of flavanols may also prevent or reduce oxidative stress from reactive oxygen species and free radicals.

In this study, Holland and his team evaluated 961 people with no dementia at baseline who participated in the Rush Memory and Aging Project, an ongoing community-based, prospective cohort. Participants were followed for 6.9 years. The sample was predominantly female (75%), white (98%),and had an average educational level of 15 years and a mean baseline age of about 81. Overall, 22% carried at least one APOE4 allele (a risk factor for susceptibility to coronary artery disease (CAD) and Alzheimer's Disease (AD)), and 42% reported a history of smoking.

The researchers looked at diet using a food frequency questionnaire and measured cognitive performance annually with about 20 standardized tests. They adjusted findings for age, sex, education, APOE4, late-life cognitive activity, physical activity and smoking.

The study examined both total flavonol intake and intake of four constituents -- kaempferol, quercetin, myricetin, and isorhamnetin. Kale, beans, tea, spinach, and broccoli were top food contributors for the natural flavonol kaempferol in the study. Tomatoes, kale, apples, and tea were main contributors for quercetin; tea, wine, kale, oranges, and tomatoes for myricetin; and pears, olive oil, wine, and tomato sauce for isorhamnetin, another flavanol.

Holland and colleagues noted that the study has several limitations, such as the fact that the sample population was white, highly educated and from the Midwest. In addition, dietary intake was recorded by self-reported food frequency questionnaires.

Reference: MedPage Today (Nov. 23, 2022) “Flavonols Linked to Slower Cognitive Decline”