Walnuts and Walnut Oil Good for the Heart
Walnuts have appeared on many “top superfoods” lists in recent years. And new research indicates that the status of the nuts as nutritional superstars is well deserved. From studies suggesting that walnuts may help prevent breast and prostate cancers, to a 2010 study that concluded that walnuts in the diet may help older people maintain healthy blood pressure, even when confronted with stressful situations, the good press about walnuts continues to mount.
Walnuts are a rich source of fiber, antioxidants, and the omega-3 fatty acid, alpha-linolenic acid. As I mentioned yesterday, omega-3 fatty acids in fish oil were recently shown to protect the brain against some of the harmful effects of a junk food diet.
Walnuts are known to be heart healthy; consumption of walnuts and walnut oil helps protect against cardiovascular disease. Now a new study reports that whole walnuts and walnut oil work in different, but complementary, ways to protect the linings of blood vessels and lower blood cholesterol levels. That’s significant, because high LDL-cholesterol is linked to an increased risk of heart disease, while undesirable changes to the lining of blood vessels (the endothelium) is a hallmark of atherosclerosis. And atherosclerosis, or hardening of the arteries, is the underlying cause of most cardiovascular disease.
Walnuts don’t just protect the heart and blood vessels by lowering cholesterol levels, though. According to a new study by scientists at Penn State, walnuts help blood vessel linings remain supple, even after meals, when they often become stiff.
Berryman CE, Grieger JA, West SG, Chen CY, Blumberg JB, Rothblat GH, et al. Acute Consumption of Walnuts and Walnut Components Differentially Affect Postprandial Lipemia, Endothelial Function, Oxidative Stress, and Cholesterol Efflux in Humans with Mild Hypercholesterolemia. J Nutr. 2013 Apr 24. [Epub ahead of print]
Davis PA, Vasu VT, Gohil K, Kim H, Khan IH, Cross CE, et al. A high-fat diet containing whole walnuts (Juglans regia) reduces tumour size and growth along with plasma insulin-like growth factor 1 in the transgenic adenocarcinoma of the mouse prostate model. Br J Nutr. 2012 Nov 28;108(10):1764-72. doi: 10.1017/S0007114511007288. Epub 2012 Jan 16.
Spaccarotella KJ, Kris-Etherton PM, Stone WL, Bagshaw DM, Fishell VK, West SG, et al. The effect of walnut intake on factors related to prostate and vascular health in older men. Nutr J. 2008 May 2;7:13. doi: 10.1186/1475-2891-7-13.
Vanden Heuvel JP, Belda BJ, Hannon DB, Kris-Etherton PM, Grieger JA, Zhang J, et al. Mechanistic examination of walnuts in prevention of breast cancer. Nutr Cancer. 2012;64(7):1078-86. doi: 10.1080/01635581.2012.717679.
West SG, Krick AL, Klein LC, Zhao G, Wojtowicz TF, McGuiness M, et al. Effects of diets high in walnuts and flax oil on hemodynamic responses to stress and vascular endothelial function. J Am Coll Nutr. 2010 Dec;29(6):595-603.