Preliminary animal research has been investigating the potential benefit walnuts may have on a variety of cancers including breast, prostate, and colorectal cancer. Please note, animal studies are provided as background to inform the additional research needed to determine the effects on humans.

According to the National Cancer Institute at the National Institutes of Health (NIH), being overweight or obese is associated with an increased risk of certain cancers, based on observational studies. Although observational studies provide valuable insight, the findings cannot definitively establish that obesity causes cancer. Despite limitations among these studies, the evidence suggests that lower weight gain during adulthood is associated with reduced risk of a number of cancers.1 Research shows that eating walnuts as part of a healthy diet does not contribute to weight gain or hinder weight loss goals.2,3,4 Walnuts can also be satisfying and may increase sense of fullness, reducing the likelihood of reaching for a second helping at dinner or an extra afternoon snack.5

A healthy eating pattern that includes a variety of plant-based foods such as vegetables, fruits, grains, oils, nuts and seeds, as well as protein and fat-free or low-fat dairy, is associated with a reduced risk of certain types of cancers, according to the Dietary Guidelines for Americans.6 Walnuts offer a variety of important nutrients, including good fats, making them an ideal ingredient for plant-based meals. Check out the plant-based eating tips and recipes below for ways to incorporate more plant foods, like walnuts, into your diet.


2 Le T, Flatt SW, Natarajan L, et al. Effects of diet composition and insulin resistance status on plasma lipid levels in a weight loss intervention in women. J Am Heart Assoc. 2016;25;5(1):e002771.

3 Rock CL, Flatt SW, Pakiz B, et al. Effects of diet composition on weight loss, metabolic factors and biomarkers in a 1-year weight loss intervention in obese women examined by baseline insulin resistance status. Metabolism. 2016;65(11):1605-13.

4 Banel DK, Hu FB. Effects of walnut consumption on blood lipids and other cardiovascular risk factors: a meta-analysis and systematic review. Am J Clin Nutr. 2009;90(1):56-63.

5 Brennan AM, Sweeney LL, Liu X, et al. Walnut consumption increases satiation but has no effect on insulin resistance or the metabolic profile over a 4-day period. Obesity (Silver Spring). 2010;18(6):1176-82.

6 U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015 – 2020 Dietary Guidelines for Americans. 8th Edition. December 2015. Available at