Walnuts are a good source of healthy fats, protein, vitamin E, minerals and phytochemicals called sterols. They're also energy-dense, so you may need to watch your portion-size, unless you're trying to gain weight.
Walnuts contain monounsaturated fatty acids and omega-3 fatty acids that are good for your heart. The United States Food and Drug Administration allows the following claim to be placed on the packaging of foods that contain whole or chopped walnuts:
Scientific evidence suggests but does not prove that eating 1.5 ounces per day of most nuts such as peanuts as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease. See nutrition information for fat content.
You can find packages of chopped walnuts or walnut halves at the grocery store, usually in the bulk item area or in the baking area. You may also find them along with mixed nuts in the snack aisle. You can also find walnuts still in their shells.
Packaged walnuts can be stored at room temperature, but once the packages are opened the walnuts should be stored in the refrigerator. Walnuts that are still in the shell can be kept at room temperature for several months.
Nutrition InformationOne ounce of walnuts (about 14 halves) contains 2.5 grams monounsaturated fatty acids, 2.6 grams omega-3 fats, 5.9 milligrams vitamin E, 1.4 micrograms selenium and 45 milligrams magnesium. Once ounce of walnuts also has 4.3 grams protein, 1.9 grams fiber and 185 calories.
United States Department of Agriculture. "Peanuts, all types, dry-roasted." Accessed April 23, 2011. http://www.nal.usda.gov/fnic/foodcomp/search/.
United States Food and Drug Administration. "FDA Qualified Health Claims." Accessed April 23, 2011. http://www.fda.gov/Food/GuidanceComplianceRegulatoryInformation/GuidanceDocuments/FoodLabelingNutrition/FoodLabelingGuide/ucm064923.htm.