Cholesterol -- a specific type of fat produced by animal cells -- provides structure to animal cell membranes, aids in the production of hormones and promotes the production of bile acids needed to digest fats. Since nuts come from plants, nuts do not contain any cholesterol. In fact, nuts may help reduce blood cholesterol levels, prompting the Food and Drug Administration to approve this qualified health claim for nutrition labels: "Scientific evidence suggests but does not prove that eating 1.5 ounces per day of most nuts as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease."
Significance of Cholesterol
The human body needs cholesterol, but large amounts of cholesterol in the blood vessels promote its accumulation along blood vessel walls. As cholesterol accumulates, it forms plaque -- a substance that makes blood vessels harden and restricts the flow of blood. High blood cholesterol, defined as a total cholesterol level of 240 mg/dL or higher, is a major risk factor for heart disease. The body produces all the cholesterol it needs, providing 75 percent of the total cholesterol, which means you should keep dietary cholesterol intake to a minimum. Choosing healthy cholesterol-free snacks, like nuts, helps keep your dietary cholesterol intake low.
Fat Impact on Cholesterol
Although dietary cholesterol contributes to blood cholesterol levels, consuming saturated and trans fats also negatively impacts blood cholesterol levels, according to the American Heart Association. Saturated fats increase low-density lipoprotein, or LDL, levels. For this reason, you should limit your intake of saturated fats to less than 7 percent of your daily calories. Trans fats not only increase your LDL cholesterol levels but also decrease your high-density lipoprotein, or HDL, levels. The "good" HDL cholesterol picks up excess cholesterol and carries it to the liver for removal from the body. For this reason, you should limit your trans fat intake to less than 1 percent of your daily calories.
Fat in Nuts
Nuts contain a significant amount of fat, with 1 oz. of tree nuts ranging from 13 to 22 g of total fat. The majority of the fat in nuts is unsaturated fat, the type of fat considered healthy because it may actually help lower blood cholesterol levels. Nuts contain no trans fat and very little saturated fat. Brazil nuts contain the highest amount of saturated fat, with 4 g per 1-oz. serving, while almonds contain the least with 1 g per 1-oz. serving.
Nut Nutrition
The Dietary Guidelines for Americans 2010, the USDA Food Pyramid and even the DASH diet supported by the American Heart Association and National Heart, Lung and Blood Institute recommend eating nuts as a part of a low-fat diet. Nuts serve as a good source of protein, fiber and minerals. But beware: don't go nuts on your nut consumption. Nuts contain fat and a lot of calories, 160 to 200 per 1-oz. serving, so keep your intake to about a handful a day.
References
- U.S. Food and Drug Administration; Qualified Health Claims; October 2009
- American Heart Association; Know Your Fats; March 2011
- University of Nebraska Cooperative Extension; Nuts for Nutrition; Alice Henneman; March 2004
- USDA National Nutrient Database; Nutrients and % DV in 1 Ounce of Tree Nuts; 2009
- USDA: Dietary Guidelines for Americans 2010 -- Chapter 5; February 2011
- USDA; Protein Foods; February 2011
