Walnuts are available year round as a delicious source of protein and other nutrients, great for use in cooking, baking and as snacks. In addition to other various health benefits, walnuts can be an important tool in helping you lose weight and may even help stave off diabetes.
There are several different types of walnut trees, but the three most often processed and consumed are the English walnut, black walnut and the white walnut. The English variety is the most popular in the United States, even though it’s not native to the continent as are the black and white walnuts. It has a thinner shell that’s easily cracked, with a milder flavor than the pungent black walnut or sweet, oily white walnut varieties.
Weight Loss Benefits
Walnuts are a nutrient-dense food, packing high ratios of the minerals manganese and copper, as well an antioxidant compound called ellagic acid that helps to block the metabolic processes causing inflammation, which can lead to insulin resistance and diabetes. Researchers at Brigham and Women's Hospital and the Harvard School of Public Health also found people trying to lose weight were three times more likely to stick to a Mediterranean style diet that included nuts and nut butters than they were a low-fat diet. This is due in part to the omega-3 fatty acids, protein, and fiber in the nuts that make you feel less hungry.
A 2005 study by L.J. Gillen et al at the University of Wollongong in Australia found that adding walnuts into the diets of diabetics improved fat and energy balance. Researchers at the Department of Preventive Medicine and Public Health, University of Navarra in Spain followed almost 9,000 subjects over 28 months ending in 2009 and discovered that those who ate nuts at least two times per week were 31 percent less likely to gain weight than those who didn’t eat nuts. The even longer Nurses' Health Study II based at Harvard University also showed that higher nut consumption among more than 28,000 study participants was not associated with greater body weight gain over eight years, but rather results in a slightly lower risk of weight gain and obesity.
When purchasing unshelled walnuts, avoid those that have a rubbery or shriveled appearance. Because walnuts turn rancid fairly quickly, shelled nuts should be kept in an airtight container and placed in your refrigerator, where they can keep for six months, or in the freezer, where they’ll stay fresh up to a year. Unshelled walnuts will keep fresh in any cool, dry location for six months. To preserve flavor and nutrients, avoid chopping nuts until you’re actually ready to use them.
Nuts are one of the most common food allergens. If you experience signs of a serious reaction after consuming nuts, including hives, swelling, wheezing, trouble breathing, or dizziness, you should avoid walnuts and products that contain them.
- University of Nebraska Food Reflections: Nuts for Health
- California Walnut Board: Tasty Tool for Weight Management