Emerging evidence over the last 3 decades have reported on the prevention and risk-reduction of heart disease and type 2 diabetes through the consumption of nuts. Previously, doctors had cautioned against eating nuts, stating that they are high in fat content which could increase cholesterol and contribute to weight gain and obesity. It is now apparent that eating a handful of nuts each day can have the opposite effects. Research has shown that nuts contain heart-healthy unsaturated fats that lower total cholesterol, including “bad” low-density lipoprotein (LDL) cholesterol, thereby reducing one’s risk for heart disease. This omega-3 fatty acid, called alpha-linolenic acid (ALA), is converted in the body into the heart-healthy fats that are present in the fish oil of fatty cold-water fish. ALA is also contained in soybean and cannabis.
A U.S. Physician’s Health Study was published in Reuters in June of 2002. This was a co-study between Brigham and Women’s Hospital and Harvard Medical School in Boston, Mass. This investigation involved 21,454 male doctors, aged 40-84, who were followed for 17 years. Those doctors (80%) who ingested at least 1 ounce (about a handful) of nuts twice a week nearly halved their mortality or death rate from sudden heart attacks compared to those doctors (20%) who rarely or never ate nuts. Also, mortality as a result of complications from coronary heart disease was reduced by 30%. The higher the consumption of nuts, the lower was the risk for any heart-related deaths, even after adjusting for age, cholesterol levels, blood pressure, diabetes, exercise, and alcohol intake.
A study published in Circulation in Sept. 2002 explained that substituting nuts for other nutritious snacks was beneficial in decreasing low density lipoprotein (LDL) cholesterol. Researchers at the Clinical Nutrition and Risk Factor Modification Center at St. Michael’s Hospital in Toronto, Canada, tested 27 men and women with an average age of 64. For 3 months, their diets consisted of a similar number of calories. During the 1st month, they ate 2 handfuls of almonds per day. Upon testing, their LDL cholesterol decreased by 9.4%. For the 2nd month, they consumed 1 handful of almonds and half of a low-fat whole-wheat muffin. Their LDL cholesterol was reduced by 4.4%. In the 3rd month, they ate an entire muffin and no almonds. Tests showed no change in cholesterol levels.
While it has been believed that the unsaturated fats in nuts are responsible for the cholesterol lowering, the vegetable protein in almonds may also be contributive. By weight, almonds have as much protein as they have fat.
Researchers at Harvard University’s School of Public Health presented an analysis showing that partaking in peanuts daily could stave off the emergence of type 2 diabetes. They published their findings in the Journal of American Medical Association in Nov. 2002. Their study involved 83,818 female nurses, aged 34 to 59, whom were followed for 16 years. Those who ate a handful of peanuts (1 oz.) or 1 tablespoon of peanut butter at least 5 times per week were up to 30% less likely to develop diabetes than those who rarely or never ate peanuts.
Although peanuts are classified as legumes, they offer as strong a reduction in mortality risk as do tree nuts. The provided protection comes from healthy unsaturated fats, fiber, and magnesium in the peanut. The fiber and magnesium especially aid in maintaining the glucose and insulin levels in a controlled balance, thereby preventing the onset of diabetes. Avoid peanut butter that contains high amounts of sugar or fatty preservatives.
In 2015, studies from different continents were compared with each other in order to assess the benefits of peanut consumption. The Shanghai Women and Men Health Studies in China and the Southern Community Cohort Study in the U.S. looked at the association between peanut intake and a reduction in deaths from cardiovascular disease and total mortality in low-income populations. Those tested were 70,000 Americans of African and European descent and 130,000 Chinese. Results showed a decrease in cardiovascular deaths of 23% – 38% and decreased total mortality of 17% – 21% . This data was consistent among the different racial groups.
Other nuts with heart-healthy fats include pecans and macadamia nuts; those which have been roasted in hydrogenated oil and coated with salt are not healthful.