Higher dietary anthocyanin and flavonol intakes are associated with anti-inflammatory effects in a population of US adults

Authors: CASSIDY, AEDIN - University Of East Anglia; ROGERS, GAIL - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; PETERSON, JULIA - Tufts University; DWYER, JOHANNA - Tufts University; LIN, HONGNUANG - Boston University; JACQUES, PAUL - Jean Mayer Human Nutrition Research Center On Aging At Tufts University

Submitted to: The American Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/28/2015
Publication Date: 5/27/2015
Citation: Cassidy, A., Rogers, G., Peterson, J.J., Dwyer, J.T., Lin, H., Jacques, P.F. 2015. Higher dietary anthocyanin and flavonol intakes are associated with anti-inflammatory effects in a population of US adults. American Journal of Clinical Nutrition. 102:172-181. https://doi.org/10.3945/ajcn.115.108555.

Interpretive Summary: Flavonoids are phytonutrients, meaning they are nutrients found naturally in plants. The main dietary sources of flavonoids are fruits and vegetables; however, they can also be found in other products such as tea and wine. Growing evidence suggests that dietary flavonoids may protect against age-related chronic diseases such as cardiovascular disease, diabetes, some cancers, Parkinson's disease, and cognitive decline. It is well-established that chronic inflammation plays a key role in development of such diseases, and while many dietary factors can influence inflammation, some data suggest that flavonoids may reduce inflammation and protect against disease. In particular, evidence suggests that three specific sub-classes of flavonoids (anthocyanins, flavonols, and flavan-3-ols) may protect against disease. Previous research examining inflammation and disease has focused on looking only at individual markers of inflammation, and in addition, there is no consensus on which biological measures are best for measuring inflammation in research studies. Thus, our study aimed to examine associations between inflammation and flavonoid intake using a wide range of biological markers to measure inflammation. To do this, we created an overall inflammatory score and examined data on over 2,000 participants in the Framingham Heart Study. Our results suggested that an overall anti-inflammatory effect may be the mechanism by which higher intake of two flavonoid subclasses, anthocyanins and flavonols, can potentially protect against chronic disease. Future research should further examine the optimal amounts and/or sources of flavonoids that are needed to reduce inflammation and disease risk.

Technical Abstract: Background: Although growing evidence from trials and population-based studies has supported a protective role for flavonoids in relation to risk of certain chronic diseases, the underlying mechanisms remain unclear. Several previous studies focused on individual inflammatory biomarkers, but because of the limited specificity of any individual marker, an assessment of a combination of biomarkers may be more informative. Objective: We used an inflammation score (IS) that integrated 12 individual inflammatory biomarkers for the examination of associations with intakes of different flavonoid classes. Design: The study was a cross-sectional analysis of 2375 Framingham Heart Study Offspring Cohort participants. Intakes of total flavonoids and their classes (anthocyanins, flavonols, flavanones, flavan-3-ols, polymers, and flavones) were calculated from validated food-frequency questionnaires. Individual inflammatory biomarkers were ranked, standardized, and summed to derive an overall IS and subgroup scores of functionally related biomarkers. Results: In multivariate analyses, an inverse association between higher anthocyanin and flavonol intakes and IS was observed with a mean +/- SE difference between quintile categories 5 and 1 of -1.48 +/- 0.32 (P-trend