Will Eating Blueberries Reduce Risk For Heart Disease?

Eating more fruit and vegetables is a common recommendation in dietary guidelines to prevent everything from obesity and heart disease to premature aging and cancer.

In this context, berries are of particular interest, as they are particularly rich in anti-oxidants and a variety of phytochemicals like polyphenols, anthocyanins, proanthocyanidins, resveratrol, flavonols, and tannins that have demonstrated beneficial effects in vitro and in vivo studies.

But randomised controlled studies on the health effects of eating berries remain scarce.

It is therefore of interest that Arpita Basu and colleagues from Oklahama State University, in a paper just published in the the Journal of Nutrition, now report the results of a randomised controlled trial of blueberries in men and women with obesity and the metabolic syndrome.

In this study, the researchers examined the effects of eight weeks of daily blueberry supplementation (50 g freeze-dried blueberries, approximately 350 g fresh blueberries) compared to equivalent amounts of fluids in 48 participants with an average BMI of around 38 kg/m2).

While blueberries did not appear to have any effect on serum glucose or lipid profiles, there was a significant decrease in systolic and diastolic blood pressures (-6 and -4%, respectively) versus controls (-1.5 and -1.2%).

There was also a roughly 30% decrease in plasma levels of oxidized LDL in the blueberry group compared to a 9% reduction in controls.

No change in weight was reported.

Although this is a short-term study of only eight weeks duration, the data does suggest that there may be beneficial effects of regular consumption of blueberries on cardiovascular risk factors. Whether or not these effects translate into better health outcomes in the long term remains to be seen.

Edmonton, Alberta

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Basu A, Du M, Leyva MJ, Sanchez K, Betts NM, Wu M, Aston CE, & Lyons TJ (2010). Blueberries Decrease Cardiovascular Risk Factors in Obese Men and Women with Metabolic Syndrome. The Journal of nutrition PMID: 20660279