This review summarizes the results on flavonoid intakes and the development of type 2 diabetes and cardiovascular diseases.
Recent advances in food composition databases have allowed the evaluation of a more comprehensive range of flavonoids in epidemiological studies. In addition, the number of randomized trials of flavonoid-rich foods has increased rapidly. Results from both cohort studies and randomized trials suggest that anthocyanidins from berries and flavan-3-ols from green tea and cocoa may lower the risk of type 2 diabetes and cardiovascular diseases. Meta-analyses of randomized trials indicate that the strongest evidence exists for a beneficial effect of green tea on LDL-cholesterol and a beneficial effect of flavan-3-ol-rich cocoa on endothelial function and insulin sensitivity. Few randomized trials had a long duration or evaluated pure flavonoid compounds.
Evidence from cohort studies and randomized trials suggest beneficial effects of food sources of anthocyanidins (berries) and flavan-3-ols (green tea and cocoa) on cardiovascular health. These findings need to be confirmed in long-term randomized trials, and evaluation of pure compounds will be important to establish what specific flavonoids and doses are effective.
aSaw Swee Hock School of Public Health, National University of Singapore, National University Health System
bDepartment of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, National University Health System, Singapore, Singapore
cDepartment of Nutrition, Harvard School of Public Health, Boston, Massachusetts, USA
dDepartment of Food Science, BioCenter, Swedish University of Agricultural Sciences, Uppsala, Sweden
Correspondence to Rob M. van Dam, Saw Swee Hock School of Public Health, National University of Singapore, MD3, 16 Medical Drive, Singapore 117597, Singapore. Tel: +65 6516 4980; fax: +65 8221 4712; e-mail: email@example.com