Nuts & Seeds Protect Against Heart Disease
By Joel Fuhrman, M.D. www.drfuhrman.com
Raw nuts and seeds are packed with nutrients. They contain lignans, bioflavonoids, minerals, and other antioxidants that protect the fragile freshness of the fats therein; they also contain plant proteins and plant sterols that naturally lower cholesterol. And because nuts and seeds supply certain fibers, phytochemicals, phytosterols, and bioactive nutrients not found in other foods (such as polyphenols and arginine), they have other beneficial effects that prevent blood vessel inflammation.
Perhaps one of the most unexpected and novel findings in nutritional epidemiology in the past five years has been that nut consumption offers such strong protection against heart disease. Several clinical studies have observed beneficial effects of diets high in nuts (including walnuts, peanuts, almonds, and other nuts) on blood lipids.1 A review of 23 intervention trials using nuts and seeds demonstrated convincingly that eating nuts daily decreases total cholesterol and LDL cholesterol.2 Not only do nuts and seeds lower LDL (bad) cholesterol and raise HDL (good) cholesterol, they can help normalize a dangerous type of LDL molecule (the small, dense LDL particles that damage the endothelial cells that line the blood vessels).3
Ellagitannins (ETs) are dietary polyphenols with potent antioxidant and other cancer chemopreventive activities that are found in berries, nuts (especially walnuts), and seeds.4 Walnuts can reduce Creactive protein and harmful plaque adhesion molecules, two significant markers of inflammation in arteries. The result is improved, and even restored, endothelial function (which includes the elastic property of arteries that allows dilation when necessary to meet an increased demand of blood).According to the researchers, walnuts are the first food to show such cardiovascular benefits.5
Eating nuts provides more benefits than simply lowering cardiovascular risk factors, such as lowering blood glucose or cholesterol levels. Studies on nuts show that they actually decrease the end point of cardiovascular death and increase overall life span.6 So far, five large prospective cohort studies (the Adventist Health Study, the Iowa Women Health Study, the Nurses’ Health Study, the Physicians’ Health Study, and the CARE Study) have examined the relation between nut consumption and the risk of atherosclerotic heart disease, and all have found a strong inverse association.
Notably, the protective effect of nut consumption on heart disease is not offset by increased mortality from other causes. In fact, nut consumption has been found to be inversely related to all-cause mortality in all tested populations, including whites, blacks, and the elderly. Eating nuts and seeds offers a well documented intervention for increasing longevity.
The beneficial effects of nut consumption observed in clinical and epidemiologic studies underscore the importance of distinguishing the differences between different types of fat. Most fats in nuts are mono and polyunsaturated fats that lower low-density lipoprotein cholesterol levels. However, the favorable fat issue does not alone account for the health benefits of nuts and seeds. Most importantly, these powerful health benefits are not achieved when nut or seed oils are substituted for whole nuts and seeds as a caloric source.
Based on the data from the Nurses’ Health Study, it was estimated that substitution of the fat from one ounce of nuts for equivalent energy from carbohydrate in an average diet was associated with a 30% reduction in heart disease risk, and the substitution of nut fat for saturated fat was associated with 45% reduction in risk.
Frank Hu, M.D., possibly the leading researcher on the value of nuts in the American diet and an associate of Walter Willet at the Harvard School of Public Health, says, “Our epidemiological studies have shown that eating about one ounce of nuts a day will reduce the risk of heart disease by over 30 percent.”
How Dr.Willet, who co-authored many of the studies that documented the value of eating nuts and seeds, can put oil instead of nuts at the base of his food pyramid, is beyond comprehension. Clearly, even respected research physicians make recommendations based on social, economic, and political motivations even when the science says something completely different.
The Physicians Health Study is the most fascinating and perhaps most important of the studies. It found that nuts and seeds do not just lower cholesterol and protect against heart attacks; components of nuts apparently have anti-arrhythmic and anti-seizure effects that dramatically reduce the occurrence of sudden death.7 These beneficial rhythm stabilizing effects of nuts and seeds are not merely due to the amount of omega-3 fatty acids they contain, but also to other beneficial qualities of these natural foods.
When 21,454 male participants enrolled in the U.S. Physicians’ Health Study were followed for an average of 17 years, researchers found a lower risk of sudden cardiac death and other coronary heart disease end points after controlling for known cardiac risk factors and other dietary habits. When compared with men who rarely or never consumed nuts, those who consumed nuts two or more times per week had reduced risks of sudden cardiac death by over 50 percent.8
Sudden cardiac death is not a heart attack. This means that the consumption of nuts powerfully reduces the chance of having a life-threatening cardiac arrhythmia called ventricular fibrillation or ventricular tachycardia. People who have heart disease do not always die of heart attacks; they die of an irregular heartbeat that prevents the heart from pumping properly. Removing nuts and seeds from one’s diet may actually increase the risk of one of these fatal rhythm disturbances.
During my 16 years of medical practice, the most common reasons patients have come to see me have been high blood pressure, high cholesterol, atherosclerosis, angina, diabetes, and being overweight. People following my nutritional advice have seen dramatic improvements in their conditions. They have lost weight, their blood pressure and cholesterol have normalized,and their atherosclerosis has reversed itself in impressive and often dramatic fashion. All of these individuals were advised to include raw nuts and seeds in their diets.
1. Hu FB; Stampfer MJ. Nut consumption and risk of coronary heart disease: a review of epidemiologic evidence. Curr Atheroscler Rep. 1999 Nov; 1(3): 204-9.
2. Mukuddem-Petersen J; Oosthuizen W; Jerling JC. A systematic review of the effects of nuts on blood lipid profiles in humans. J Nutr. 2005; 135(9): 2082-9.
3. Lamarche B; Desroche S; Jenkins DJ; et al. Combined effects of a dietary portfolio of plant sterols, vegetable protein, viscous fiber and almonds on LDL particle size. Br J Nutr. 2004: 92(4):654-63.
4. Cerda B; Tomas-Barberan FA; Espan JC. Metabolism of antioxidant and chemopreventive ellagitannins from strawberries, raspberries, walnuts, and oak-aged wine in humans: identification of biomarkers and individual variability. J Agric Food Chem. 2005; 53(2):227-35.
5. Ros E; Naatez I; Parez-Heras A; et al. A walnut diet improves endothelial function in hypercholesterolemic subjects: a randomized crossover trial. Circulation. 2004; 109(13):1609-14.
6. Ellsworth JL; Kushi LH; Folsom AR. Frequent nut intake and risk of death from coronary heart disease and all causes in postmenopausal women: the Iowa Women’s Health Study. Nutr Metab Cardiovasc Dis. 2001; 11(6):372-7.
7. Yuen AW; Sander JW. Is omega-3 fatty acid deficiency a factor contributing to refractory seizures and SUDEP? A hypothesis. Seizure. 2004; Mar 13(2): 104-7.
8. Albert CM; Gaziano JM; Willett WC; Manson JE. Nut consumption and decreased risk of sudden cardiac death in the Physicians’ Health Study. Arch Intern Med. 2002; 162(12):1382-7.