Don't avoid nuts because you're afraid they'll make you gain weight. Nuts provide about 19 percent of the polyphenols in the typical American diet, according to an article published in "Food and Function" in 2012. Walnuts contain more of these antioxidants -- which help reduce inflammation, limit your risk for clogged arteries and lower your cholesterol levels -- than other types of nuts.
Walnuts and Cholesterol
Getting 40 percent of your fat calories from walnuts will lower your cholesterol more than getting the same amount of fat from olive oil, but not as much as getting this fat from almonds, according a study published in "Nutrition, Metabolism and Cardiovascular Diseases" in June 2011. Consuming walnuts lowered the low-density lipoprotein, or bad cholesterol, of study participants by about 11 percent after four weeks.
While getting about 14 percent of your calories each day from walnuts appears to be beneficial for lowering your cholesterol and triglycerides, it doesn't affect everyone the same, according to a study published in "The European Journal of Clinical Nutrition" in March 2010. In the study, people with higher cholesterol levels experienced greater decreases in their cholesterol than those with lower or normal cholesterol levels.
Walnut Consumption and Weight
Eating walnuts regularly isn't likely to cause weight gain, and may actually help prevent weight gain. People who ate nuts at least twice a week had less of a risk for gaining weight than those who ate nuts less often, according to a study published in "Obesity" in January 2007. Walnuts were the type of nut eaten most often by participants in the study, who also frequently ate almonds, hazelnuts and peanuts.
The type of walnut you eat will affect whether or not it has cholesterol-lowering benefits. A study published in "The Journal of Medicinal Food" in August 2011 found that eating 30 grams of English walnuts each day lowered cholesterol, but eating the same amount of black walnuts didn't have any significant effect. Consume walnuts in place of other, less healthy foods and stick to a serving of about 1 ounce, since walnuts are high in calories.
- USDA Nutrient Data Laboratory: Nuts, Walnuts, English
- Food and Function: Nuts, Especially Walnuts, Have Both Antioxidant Quantity and Efficacy and Exhibit Significant Potential Health Benefits
- Nutrition, Metabolism and Cardiovascular Diseases: Crossover Study of Diets Enriched With Virgin Olive Oil, Walnuts or Almonds. Effects on Lipids and Other Cardiovascular Risk Markers
- Journal of Medicinal Food: Cardiovascular Effects of Consumption of Black Versus English Walnuts
- European Journal of Clinical Nutrition: Long-term Walnut Supplementation Without Dietary Advice Induces Favorable Serum Lipid Changes in Free-living Individuals
- Obesity: Nut Consumption and Weight Gain in a Mediterranean Cohort: The SUN Study
Based in Massachusetts, Jessica Bruso has been writing since 2008. She holds a master of science degree in food policy and applied nutrition and a bachelor of arts degree in international relations, both from Tufts University.