In the last 6 weeks of the year, most of us are exposed to more nuts than at any other time. . .and I’m not just talking about the ones camped out by the punch bowl or in the long check-out lines at WalMart! As family gatherings and festive occasions proliferate, we’re likely to find little bowls of nuts, cans of cashews and peanuts, fruit cakes, trail mix, brittles and brownies. . .all chocked full of nuts. Contrary to widespread belief, nut consumption can actually be a healthful addition to one’s diet. Let’s explore this thought further.
Many people consider nuts off-limits because of their high fat content, but careful research over the last several decades has actually cracked this misconception. Remember, not ALL fats are bad. Saturated fats raise cholesterol levels; polyunsaturated and/or monounsaturated fats actually decrease them. In fact, regular nut consumption can have a beneficial role in prevention of heart disease and cancer, and can benefit weight control as well. While nuts have specific nutritional profiles that vary from one family to another, they all provide calories, good fat, plant protein, dietary fiber, essential fatty acids, vitamins, and minerals. They also contain phytochemicals (“plant-derived chemicals”) of different types and amounts that can act as antioxidants and up to 8 different sterols in the plant fat. These latter ingredients are thought to lower cholesterol and reduce risks of both heart disease and colon cancer. Let’s shell out a few specifics in the following paragraph.
Almonds, which belong to the rose family, are native to Asia. They contain more calcium than any other nut, are good sources of folic acid, and vitamin E, and have the highest fiber content of all nuts. Cashews, native to Brazil, are high in monounsaturated fats, and vitamin E. In India, cashews are considered to be an aphrodisiac and a restorer of lost vigor. Macadamia nuts, native to Australia, have the highest percentage of monounsaturated fat of all nuts. They are also one of the few foods that contain a significant amount of palmitolic acid, a substance whose role in the diet is still not completely understood. Pecans, indigenous to the southern United States, are high in vitamin E and monounsaturated fats. They have recently been shown to help lower LDL cholesterol levels. Peanuts are linked to the same health benefits, though they are technically NOT NUTS, but legumes. However, the spreadable derivative, peanut butter, is not shown to provide these benefits– probably because most commercial peanut butters contain harmful hydrogenated oil that counteracts peanuts’ healthy components. Finally, walnuts are high in alpha linolenic acid, which is an omega 3 fatty acid. This ingredient makes walnuts a good source of fat for vegetarians who do not eat fish. Because the kernel of the nut resembles the human brain, walnuts have always been considered a food that boosts the intellect. Armed with all this knowledge, you’ll now qualify as a nutty conversationalist at your next cocktail party! Having gleaned these kernels of information, let’s move on. . .
To date, there have been 5 large epidemiological studies examining the relationship between nut consumption and coronary heart disease. All of these studies found an inverse relationship between nut intake and CHD risk. In the most recent study, the Nurses’ Health Study involving 86,000 women, researchers found that women who ate at least five ounces of nuts per week had a 35% lower risk of CHD than women who rarely ate nuts. These findings are corroborated by similar studies in men.
Several possible reasons exist for these findings. Being rich in unsaturated fats, nuts reduce blood lipids naturally. Second, nuts are rich in the amino acid arginine, a precursor of nitric acid, which in turn relaxes blood vessels and inhibits clotting. The high levels of magnesium,selenium, copper, folic acid, fiber, and vitamin E in nuts may also have heart-protecting qualities. And, as above, walnuts contain alpha-linolenic acid, an omega-3 fatty acid precursor known to protect against heart disease. Have I cracked a few of your misconceptions yet?
Have you been avoiding regular nut consumption as a fat-conscious American? Well, researchers have shown that including nuts in the diet does not appear to cause weight gain, as long as total calories are controlled. In an 18 month study conducted at Brigham and Women’s Hospital in Boston, Massachusetts, researchers compared a diet containing 35% calories from fat to a low fat diet in 101 overweight men and women. In both of the groups, total daily calories were restricted to 1200 calories for women and 1500 calories for men. The additional fat in the moderate fat group came from nuts, and olive and canola oils. After six months, weight loss was comparable in both groups. Interestingly, after 18 months, 80% of the people assigned to the low-fat eating group had dropped out of the study, while 54% of the people assigned to the nuts and oil consumption arm of the study remained. The researchers concluded that a moderate fat diet contributes more flavor and variety, and that this factor explained the higher participation rates. The folks eating nuts had a greater sense of dietary satisfaction and better controlled hunger than their counterparts. So, if you’ve always felt a little nutty about including cashews, walnuts, and pecans in your weight loss efforts, reconsider that stance; with appropriate exercise and overall calorie control, they could help you become a shell of your former self!
How nuts help to prevent various cancers is still a subject of intense research. The high antioxidant concentration and high fiber content of these foods are certainly two key factors. Additionally, the mother lode of essential trace minerals in nuts plays a role as well. Defining the importance of specific phytochemicals in this ongoing research will continue to be a major thrust in research defining cancer-protective effects. In the meantime, it behooves all of us to squirrel away this information and broaden our regular consumption of nuts.
As the last big shopping week before Christmas throttles into high gear, remember to take time for proper eating habits, sufficient rest, and regular exercise. Include an ounce or two of walnuts, cashews, pecans to your on-the-go snacking for nutritious calorie intake. Remember, this year, you’ll have several reasons to ‘go nuts’ during the holidays. . .and not all of them bad.
Stephen L. Hines, M.D.
December 2001
