One of the reasons high fruit and vegetable consumption is thought to reduce cardiovascular risk is because of a high concentration of flavonoids, in particular the flavonoid Quercetin. A study published in the British Journal of Clinical Nutrition found that Quercetin supplementation can reduce blood pressure and plasma oxidised LDL concentrations in overweight, high risk individuals.

Over a treatment period of 6 weeks overweight individuals with a high cardiovascular risk were supplemented with Quercetin at a dose of 150 mg per day. It was found that that Quercetin supplementation significantly reduced systolic blood pressure and that this effect was most pronounced in subjects aged 25–50 years.

In addition, Quercetin significantly reduced plasma concentrations of atherogenic oxidised LDL. The problem LDL in the blood and arteries.

The reason Quercetin was more effective in younger age individuals may be due to the ability of Quercetin to improve vasodilatation. Poor vasodilatation and endothelial function may be the major mechanism for high blood pressure in younger to middle age individuals.

In older age people however hypertension is more likely related to vascular damage and atherosclerotic changes. Supplementing with Quercetin may provide rapid reductions in blood pressure, while increasing dietary sources i.e. fruits and vegetables would provide greater global cardiovascular risk reduction overtime.

Egert S,et al. Quercetin reduces systolic blood pressure and plasma oxidised low-density lipoprotein concentrations in overweight subjects with a high-cardiovascular disease risk phenotype: a double-blinded, placebo-controlled cross-over study. Br J Nutr. 2009 Oct;102(7):1065-74.