Abstract
Purpose :
The majority of research performed to date has examined the effects of commonly known antioxidants such as vitamins C, E and A, and carotenoids on age-related macular degeneration (AMD) risk and progression. To date, there is limited research on promising phytochemicals with antioxidant and anti-inflammatory properties, including flavonoids. Therefore, we aimed to establish the independent association between dietary intake of total flavonoids as well as the six common flavonoid classes (flavonols, flavan-3-ols, flavones, flavanones, anthocyanins, and isoflavones) with the prevalence and 15-year incidence of AMD, independent of potential confounders.
Methods :
At baseline, 2856 adults aged 49+ years were included in prevalence analysis and of these 2037 were followed up 15-years later and therefore, included in incidence analysis. Dietary intake was assessed using a semi-quantitative food-frequency questionnaire (FFQ). Estimates of the flavonoid content of foods in the FFQ were assessed using the US Department of Agriculture Flavonoid, Flavone and Proanthocyanidin databases. AMD was assessed from retinal photographs.
Results :
In cross-sectional analysis, each 1-SD increase in intake of total flavonol and total flavanone was associated with reduced odds of any AMD: multivariable-adjusted odds ratio, OR, 0.74 (95% confidence intervals, CI, 0.58-0.96); and OR 0.76 (95% CI 0.60-0.97), respectively. Each 1-SD increase in intake of all types of flavonoids (total flavonoid) was associated with reduced likelihood of any AMD, OR 0.76 (95% CI 0.58-0.98). A significant trend (p=0.02) was observed between increasing intake of total flavanone (from first to fourth quartile) and reduced odds of incident late AMD, after multivariable adjustment.
Conclusions :
Our findings suggest an independent and inverse association between dietary intake of flavonoids and the likelihood of having AMD. There is evidence that flavonoids can minimize oxidative damage and inflammation, and these properties could help explain the beneficial influence flavonoids might have on AMD pathogenic processes. Additional prospective cohort studies, however, are needed to validate these findings.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.