MedWire News: A small exploratory study suggests that walnut consumption may improve endothelium-dependent vasodilation in individuals with Type 2 diabetes.
The findings provide further evidence that eating walnuts may have vascular benefits. Previous studies reported by MedWire News have demonstrated beneficial effects on serum lipids.
For this study, David Katz (Yale University School of Medicine, Derby, Connecticut, USA) and colleagues recruited 24 individuals with Type 2 diabetes aged 58 years on average.
They randomly assigned the participants to consume their normal diet (controls) or their normal diet plus 56 g (366 kcal) walnuts per day for a period of 8 weeks. After the first 8 weeks, all participants went through an 8-week washout period before swapping to the opposite diet for another 8 weeks.
All individuals initially underwent a 4-week run-in period to allow for diet and weight stabilization, during which time no walnuts or vasoactive medication or supplements were consumed.
Endothelial function testing was carried out by the researchers using flow-mediated dilation (FMD).
They found that FMD was significantly improved in the walnut supplemented group versus controls at study completion, by 2.2% versus 1.2%.
Total and low-density lipoprotein cholesterol were also reduced in the walnut supplemented group by 9.7 and 7.7 mg/dl (0.25 and 0.20 mmol/l), respectively, but these reductions were not statistically significant compared with controls.
Of note, anthropometric measures, glycated hemoglobin, and insulin sensitivity did not change significantly in the walnut supplemented group versus controls.
Writing in the journal Diabetes Care, the authors conclude: “Despite its limitations, this study provides evidence that regular walnut consumption improves endothelial function in Type 2 diabetic individuals and may therefore help reduce cardiovascular disease risk in this high-risk population.”
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010
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