Walnuts Keep Your Blood Flowing
It’s no secret that nuts are good for your heart. We know that consuming nuts can dramatically reduce cardiovascular disease risk, but scientists are just beginning to figure out how this works. We have learned that almonds have a potent antioxidant effect, leading to decreases in circulating oxidized LDL, helping to keep the arteries clear of atherosclerotic plaque.1
Like all nuts, walnuts are rich in fiber, minerals, micronutrients, phytosterols, antioxidants, and monounsaturated fats, but walnuts stand out because of their distinctively high levels of ALA, an omega-3 fatty acid and precursor to EPA and DHA.
Researchers at Yale University wondered whether walnuts would have beneficial effects on blood vessel function in individuals at risk for cardiovascular disease—those with type 2 diabetes.
Twenty-four subjects with type 2 diabetes were included in the study. Half were assigned to supplement their diets with 2 ounces of walnuts per day for 8 weeks.
The researchers tested flow-mediated dilation (FMD), which is a measure of how well the endothelial cells, the cells that line all blood vessels, are working to keep blood pressure in a favorable range. One of the endothelial cells’ most important jobs is to produce nitric oxide, which regulates blood pressure by relaxing the muscle in the walls of the arteries.
After 8 weeks of daily walnut consumption, flow-mediated dilation was improved—the blood vessels were able to dilate more in the subjects who ate walnuts.2 This is good news for overall cardiovascular disease risk since loss of endothelial function is one of the initiating events in atherosclerotic plaque development.
Want another reason to eat some walnuts? They may also protect against breast cancer and prostate cancer, according to animal studies.3
1. Jenkins DJ, Kendall CW, Marchie A, et al. Almonds Reduce Biomarkers of Lipid Peroxidation in Older Hyperlipidemic Subjects. J. Nutr. 138: 908-913, 2008.
USDA/Agricultural Research Service (2008, November 4). Antioxidant Effects From Eating Almonds. ScienceDaily. Retrieved February 25, 2010, from http://www.sciencedaily.com /releases/2008/10/081031213057.htm
2. Ma Y, Njike VY, Millet J, et al. Effects of walnut consumption on endothelial function in type 2 diabetic subjects: a randomized controlled crossover trial. Diabetes Care. 2010 Feb;33(2):227-32. Epub 2009 Oct 30.
Medscape Medical News: Walnuts Shown to Improve Endothelial Function in Diabetics
3. Eurekalert! Walnuts slow prostate tumors in mice: UC Davis research shows walnuts affect genes related to tumor growth