Scientific research has found an association between cognition and dietary flavonoids which have anti inflammatory and antioxidant properties. This study investigated flavonoid in foods – including quercetin found in onions, as well as myricetin, kaempferol and isorhamnetin – and their effect on cognitive performance.
The study involved 961 subjects between the ages of 60 and 100 years, who were followed for around seven years. Cognitive performance was assessed annually and their flavonol intake was also measured.
The research showed that a higher dietary intake of total flavonols and flavonol constituents was associated with a slower rate of cognitive decline. The observed associations were independent of other factors such as cardiovascular condition and lifestyle.
The cognitive score of those who ate the most flavonols declined 0.4 units per decade more slowly than those who ate the fewest flavonols. These results were maintained, even after adjusting for other factors that can affect memory, such as age, gender and smoking.
Although the mechanisms are not fully understood, the antioxidant and anti-inflammatory properties of flavonols may have the ability to diminish or even prevent cellular damage, extending to the brain.
In addition, the antioxidant characteristics of dietary flavonols may allow them to prevent and/or reduce oxidative stress from reactive oxygen species and free radicals.
The study’s findings suggest that dietary intake of total flavonols and flavonol constituents may slow the rate of decline in global cognition, and in several cognitive abilities including episodic memory, semantic memory, visuospatial ability, perceptual speed and working memory.
Practice Tips
- Flavonoids are a large class of bioactive polyphenolic compounds found in plants, with substantial amounts found in fruits and vegetables, and especially in onions
- Foods that are high in flavonols and flavonol constituents (specifically quercetin in onions, as well as myricetin, kaempferol and isorhamnetin) may help reduce the effects of cognitive decline in an ageing population
- Ensure your diet includes the following foods:
○ Quercetin – onions, tea, wine, kale, oranges
○ Kaempferol – tomatoes, kale, apples, tea
○ Myricetin and Isorhamnetin – pears, olive oil, wine
Reference
Thomas Monroe Holland, Puja Agarwal, Yamin Wang, Klodian Dhana, Sue E. Leurgans, Kyla Shea, Sarah L Booth, Kumar Rajan, Julie A. Schneider, Lisa L. Barnes. Association of Dietary Intake of Flavonols with Changes in Global Cognition and Several Cognitive Abilities. Neurology Nov 2022, 10.1212/WNL.0000000000201541; DOI:10.1212/WNL.0000000000201541.
