A walnut is a nut of any tree of the genus Juglans, particularly the Persian or English walnut. It is used after being processed while green, for pickled walnuts, or after full ripening while brown, for its nutmeat. In terms of the walnut’s nutrition facts, per ounce (28 grams), walnuts contain 7 grams of fat and 16 grams of unsaturated fat. Though people are intimidated by the word ‘fat’, unsaturated fats are good for one’s health. Walnuts have the ability to improve blood cholesterol levels and decrease the risk of cardiovascular disease.

One of the benefits of walnuts is that they are a great source of dietary fiber. Dietary fiber can prevent constipation and help the body excrete biological wastes, while maintaining healthy blood sugar levels. An individual should consume at least 25-38 grams of fiber, depending if one is male or female. This is particularly helpful for individuals with diabetes because fiber prevents lethal sugar crashes. 

Fiber can also decrease the bad cholesterol levels that accumulate in the arteries and blood vessels, thus contributing to enhanced heart health. Walnuts also contain omega-3 fatty acids, which have been found to lower cholesterol levels in individuals with high blood cholesterol.

The magnesium content in walnuts has been directly associated with enhancing the quality, length, and calmness of sleep. It also helps reduce sleep disorders and the chances of insomnia by regulating the body metabolism. Furthermore, walnuts contain important minerals that contribute to proper bone health such as magnesium, phosphorus, manganese, copper, and selenium. Inadequate levels of these minerals have been associated with the development of osteoporosis.

Manganese is an important mineral for energy production and antioxidant defense. Some enzymes need manganese to destroy harmful biological waste products, called free radicals. This can help prevent cancer and many other diseases.

Walnuts have potential health benefits for the brain and aid in improved memory and brain functioning. The walnut is a rich source of ALA, an omega-3 fatty acid. This can improve motor and behavioral skills in older adults. Individuals who are deficient in omega-3 fatty acids have been associated with depression and a decline in brain functioning. Omega-3 fatty acids have the potential to slow the growth of cancer cells and even reduce the risk of breast cancer. Also, per a research study, a combination of beta-sitosterol, which is present in walnuts, with vitamin E has prevented prostate cancer. Thus, it is a good idea to try eating a handful of walnuts per day. Eating about 28 walnut halves a day provides enough antioxidants and phytosterols that may help reduce the risk of cancer.

Additional Resources:

Anderson, J. W., Baird, P., Davis Jr, R. H., Ferreri, S., Knudtson, M., Koraym, A., ... & Williams, C. L. (2009). Health benefits of dietary fiber. Nutrition reviews, 67(4), 188-205.

Bazzano, L. A. (2008). Effects of soluble dietary fiber on low-density lipoprotein cholesterol and coronary heart disease risk. Current atherosclerosis reports,10(6), 473-477.

Damo, S. M., Kehl-Fie, T. E., Sugitani, N., Holt, M. E., Rathi, S., Murphy, W. J., ... & Chazin, W. J. (2013). Molecular basis for manganese sequestration by calprotectin and roles in the innate immune response to invading bacterial pathogens. Proceedings of the National Academy of Sciences, 110(10), 3841-3846.

Feldman, E. B. (2002). The scientific evidence for a beneficial health relationship between walnuts and coronary heart disease. The Journal of nutrition, 132(5), 1062S-1101S.

Slavin, J. L. (2005). Dietary fiber and body weight. Nutrition, 21(3), 411-418.

Takeda, A. (2003). Manganese action in brain function. Brain Research Reviews, 41(1), 79-87.

Helpful Peer-Reviewed Medical Articles:

Feldman, E. B. (2002). The scientific evidence for a beneficial health relationship between walnuts and coronary heart disease. The Journal of nutrition, 132(5), 1062S-1101S.

Vinson, J. A., & Cai, Y. (2012). Nuts, especially walnuts, have both antioxidant quantity and efficacy and exhibit significant potential health benefits. Food & function, 3(2), 134-140.

Reiter, R. J., Manchester, L. C., & Tan, D. X. (2005). Melatonin in walnuts: influence on levels of melatonin and total antioxidant capacity of blood.Nutrition, 21(9), 920-924.

Joseph, J. A., Shukitt-Hale, B., & Willis, L. M. (2009). Grape juice, berries, and walnuts affect brain aging and behavior. The Journal of nutrition, 139(9), 1813S-1817S.

Savage, G. P. (2001). Chemical composition of walnuts (Juglans regia L.) grown in New Zealand. Plant Foods for Human Nutrition, 56(1), 75-82.

Tapsell, L. C., Gillen, L. J., Patch, C. S., Batterham, M., Owen, A., Baré, M., & Kennedy, M. (2004). Including walnuts in a low-fat/modified-fat diet improves HDL cholesterol-to-total cholesterol ratios in patients with type 2 diabetes. Diabetes care, 27(12), 2777-2783.