A recently published longitudinal study has provided strong new evidence linking sustained low intake of flavonoids to significantly increased risk of Alzheimer’s disease.
The study was conducted by a team of US researchers over the course of nearly twenty years, measuring the flavonoid intake of the 2,801 participants using dietary questionnaires every four years.
The results showed a strong association between low flavonoid consumption and increased risk of Alzheimer’s disease and related dementias (ADRD), although interestingly not all flavonoids seemed to provide the same benefits. Low intake of flavonols and flavonoid polymers (found in apples, pears, and tea) was associated with a twice the risk of developing ADRD, whereas low intake of anthocyanins (blueberries, strawberries, and red wine) increased this risk four-fold.
The authors claim that these results are particularly good news for prevention of ADRD given that relatively minor changes in diet seem to be able to make a significant difference in risk, even when made later in life. With no effective drugs available for the condition, prevention remains key.
Though one of the largest and most comprehensive studies of its kind, it is of course not without limitations. It showed association of low intake of flavonoids with increased ADRD risk, but not that this factor was the cause of the condition. It also relied on self-reported data to do so, although the researchers excluded information from participants in the years leading up to dementia diagnosis in order to improve accuracy. Participants were also of European descent, limiting the generalisability of the study.
Source: Science Daily
Jacques PF, Au R, Blumberg JB, Rogers GT, Shistar E. Long-term dietary flavonoid intake and risk of Alzheimer disease and related dementias in the Framingham Offspring Cohort. Am J Clin Nutr. 2020 Apr 22; nqaa079. DOI: 10.1093/ajcn/nqaa079
