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Nutrition in a Nutshell
The Zimmerman Files

Nut trees are in full bloom in the orchards around my Chico home – and not just a few trees in someone’s backyard. We are talking about hundreds of acres of almond and walnut trees that are festooned each spring with gorgeous pink and white blossoms. California is the only state that commercially produces almonds accounting for 80 percent of world almond production. Incredibly, such a huge business depends upon warm weather that coaxes the tiny bee from its hive to pollinate the blossoms. Keeping bees healthy and happy is a major investment for almond farmers, as 1.2 million hives are required each year to pollinate California’s 550,000 acres of almonds.

California’s walnut orchards account for 226,000 acres in production and another 30,000 planted in young non-bearing trees. Virtually all of the walnuts sold in the United States come from this region. Unlike almonds, walnuts do not require bees for pollination. Male and female walnut trees cross-pollinate. While bees shun wind, it provides the necessary vehicle for walnut pollen to be carried from one tree to another. It’s an annual timing event, with almonds blooming about a month before walnuts. Farming aside, what are the health benefits of adding nuts to your diet?

Health Benefits of Nuts

Nuts contain all the major macronutrients: protein, carbohydrate, and fat. The total protein content is relatively high, which make nuts a good source of plant protein. Moreover, the low Lysine to Arginine ratio in nuts contributes to cardiovascular health. The fats in nuts are primarily unsaturated with low levels of saturated fats. Other bioactive molecules in nuts that contribute to health are fiber, phytosterols, vitamins, antioxidants, and minerals. How do these various nutrients work for disease prevention?

Cardiovascular Syndrome – Numerous studies have shown that tree nuts reduce LDL cholesterol by up to 19 percent. Several components of nuts, including plant sterols, dietary fiber and antioxidants are responsible for this effect. Four large epidemiological studies of prevention of coronary heart disease have shown that the risk of CHD is 37 percent lower for those consuming nuts more than four times per week. Results of long-standing research from Boston’s Women’s Health Study and the Physician’s Health Study suggest that a heart-healthy diet low in saturated fats, high in fruits and vegetables and includes nuts, results in greater cholesterol lowering.

Adding nuts to diets typically used to reduce cholesterol lowers cholesterol more than a nut-less regimen. Walnuts, which are high in omega-3 fatty acids, have been shown to improve blood vessel function in patients with high cholesterol. Walnuts and olive oil are staples in the Mediterranean-Style diets. The omega-3 fatty acids in these foods reduce the risk of CHD, even when eaten with a high fat meal.

Metabolic Syndrome – is a term used to group obesity, insulin resistance, lipid dysfunction, hypertension and risk of CHD. Because of its connection with heart disease, the metabolic syndrome has been closely studied. Scientists have found that adding nuts to a test meal of white bread blunts the rise in blood glucose that normally results from eating such a high glycemic food. Scientists believe that nuts may help regulate glucose metabolism by suppressing appetite, slowing gastric emptying and intestinal transit time, reducing fat absorption, and increasing the elimination of cholesterol from the body. The minerals, folic acid and phytosterols in nuts contribute to lowering risk of cardiovascular and metabolic syndromes, according to Spanish researchers.

Weight Gain from Nuts? Despite the common belief that nuts with their high fat content must be fattening, it has been documented that nuts can actually contribute to weight loss. In a twenty-eight month study that included 8,865 adult men and women, Spanish researchers found that participants who ate nuts two or more times per week had a significantly lower risk of weight gain. Australian scientists also report that nuts are unlikely to contribute to weight gain. They may in fact contribute to weight loss, by suppressing appetite and fat absorption. Furthermore, nut consumption counteracts a common factor in CHD and metabolic syndrome – that is, disordered fat metabolism. The polyphenol antioxidants and Arginine in nuts appear to also improve endothelial (lining of arteries) function.

Anti-Cancer and Anti-Aging – The benefit of eating nuts with their high phytoestrogen and selenium content in preventing cancers of the breast and prostate has been well documented. However more recent work indicates that nut lignans may also contribute to reducing colorectal cancer.

Oxidative damage is the basis of chronic degenerative disease and aging. Countering aging therefore relies on antioxidants found in a diet rich in fruits, vegetables and unrefined cereals and grains. Several tree nuts including walnuts, pecans and chestnuts contain high levels of antioxidants. Even the lowly goober (peanut) is very high in antioxidants, particularly if the red skin is intact. If we zoom in closer to see what goes on in the cell, we’ll find that oxidative damage to proteins (glycation) and DNA (strand breaks) contributes significantly to aging. Almonds appear to reduce DNA and protein damage. You can get a good selection of nuts, some organic, from NOW Foods, including Almonds, Walnuts, Brazils, Organic Cashews, Pecans, Pine nuts and Pistachios.



References
“California Almond Facts” The Almond Board of California, 2005. www.almondboard.com.

Personal communication 3/06/07 with Amy G Myrdal, MS, RD Marketing Director, California Walnut Commission.

Brufau, G; Boatella, J; Rafecas, M; “Nuts: Source of Energy and Macronutrients” Br J Nutr 2006;Suppl 2:S24-8

Griel, AE; Kris-Etherton, PM; “Tree Nuts and the Lipid Profile: a Review of Clinical Studies” Br J Nutr 2006;Suppl 2:S68-78.

Kelly, JH Jr; Sabate, J; “Nuts and Coronary Heart Disease: an Epidemiological Perspective:” Br J Nutr 2006;Suppl 2:S61-7

Cortes, B; et al; “Acute Effects of High-Fat Meals Enriched with Walnuts or Olive Oil on Postprandial Endothelial Function” J Am Coll Cardiol 2006;48(8):1666-71.

Cortés, B; et al; “Acute Effects of High-Fat Meals Enriched with Walnuts or Olive Oil on Postprandial Endothelial Function” J Am Coll Cardiol 2006;48(8):166671.

Josse, AR; et al; “Almonds and Postprandial Glycemia – a Dose-Response Study” Metabolism 2007;56(3):400-4.

Salas-Salvado, J; et al; “Dietary Fiber, Nuts and Cardiovascular Diseases” Br J Nutr 2006;Suppl 2:S45-51.

Segura, R; et al; “Other Relevant Components of Nuts: Phytosterols, Folate and Minerals” Br J Nutr
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Bes-Rastrollo M; et al; “Nut Consumption and Weight Gain in a Mediterranean Cohort: The SUN Study” Obesity 2007;15(1):107-16.

Rajaram, S; Sabate, J; “Nuts, Body Weight and Insulin Resistance” Br J Nutr 2006;Suppl 2:S79-86.

Coates, AM; Howe, PR “Edible Nuts and Metabolic Health” Curr Opin Lipidol 2007;18(1):25-30.

Cotterchio, M; et al; “Dietary Phytoestrogen Intake is Associated with Reduced Colorectal Cancer Risk” J Nutr 2006;136(12):3046-53.

Blomhoff, R; et al; “Health Benefits of Nuts: Potential Role of Antioxidants” Br J Nutr 2006;Suppl 2:S52-60.

Jenkins, DJ; et al; “Almonds Decrease Postprandial Glycemia, Insulinemia, and Oxidative Damage in Healthy Individuals” J Nutr 2006;136(12):2987-92.