This June, approximate 70.1 million U.S. fathers will be celebrated by their children1 and by the year 2050, the US Census Bureau expects 175.4 million men to become new dads2. However, over 70 million couples worldwide experience sub-fertility or infertility. And in 30-50% of these cases, infertility is attributed to the male partner. Here's some news that will be valuable to men who are hoping to join the ranks of new dads.
Research3 published in the October issue of Biology of Reproduction reports that 75 grams (approximately 2.5 oz) of walnuts consumed per day in a group of healthy young men between 21-35 years of age, improved sperm vitality, motility, and morphology (normal forms) – key elements of male reproductive health.
According to Professor Wendie Robbins, PhD, R.N., F.A.A.N., who led the research at the University of California, Los Angeles, "The positive result of walnuts on sperm may be a result of their unique nutrient profile." Walnuts are the only nut with an excellent source of alpha-linolenic acid (ALA) – the plant-based omega-3 fatty acid, and this study reported higher amounts of ALA provided by walnuts correlated with less frequent aneuploidy. (Aneuploidy is abnormal cell chromosome numbers, which can result in genetic abnormalities such as Down syndrome.) Whether adding walnuts to the diet will go beyond the shifts in sperm parameters as seen in this study to improving birth outcomes for men within fertility clinic populations or in the general population is not yet known and will require further research.
Additional research has investigated the benefit of walnuts in other areas of men's health including prostate cancer, cardiovascular disease and cognitive decline.
Defending Dad's Health With Walnuts:
Prostate Cancer is a leading cause of male cancer deaths in the United States.4 Recent research from the University of California at Davis and the U.S. Department of Agriculture Western Regional Research Center in Albany, California found that prostate tumors in mice fed the human equivalent of three ounces per day of walnuts were approximately 50% smaller and grew 30% slower than prostate tumors in control mice.56 Please note further research is needed to determine effects and/or benefits in humans.
Heart disease is the leading cause of death for men in the United States.7 Over two decades of extensive published research has uncovered various heart health benefits of walnuts including maintaining a healthy cholesterol level. Due to the strength of evidence supporting cardiovascular health, the U.S. Food and Drug Administration approved one of the first qualified health claims for a whole food for walnuts in March 2004.8
Cognitive Decline: Men over the age of 65 are more likely to suffer cognitive impairment than women of the same age according to a recent Mayo Clinic Study.9 While there is no known cure for dementia or Alzheimer's disease, walnuts have been shown to aid in improving cognitive function. Animal research published in the British Journal of Nutrition found a diet containing as much as 6% walnuts (equivalent to one ounce or 1/4 cup in humans) was able to reverse age-related motor and cognitive deficits in aged rats.10 Please note further research is needed to determine effects and/or benefits in humans.
Just a handful of California Walnuts provides more alpha-linolenic acid (ALA), the plant-based essential omega-3 fatty acid than any other nut!11 This Father's Day, nourish the men in your life and wow their taste buds with Dad Alex Stratta's Walnut Crusted Salmon with Stewed Chickpeas and Kale - a delicious way to incorporate walnuts into a healthy and yummy dish!
To learn more about how walnuts may help the health of the men in your life, see our Natural Defenders Toolkit section of our website.
6 Because this is animal research the results in humans are unknown.
8 Supportive but not conclusive research shows that eating 1.5 ounces of walnuts per day, as part of a low saturated fat and low cholesterol diet, and not resulting in increased caloric intake may reduce the risk of coronary heart disease." One ounce of walnuts provides 18g of total fat, 2.5g of monounsaturated fat, 13g of polyunsaturated fat, including 2.5g of alpha-linolenic acid – the plant-based omega-3.
9 The Incidence of MCI Differs by Subtype and is Higher in Men," Jan. 25, 2012, Neurology, American Academy of Neurology.
10 Dose-dependent effects of walnuts on motor and cognitive function in aged rats. British Journal of Nutrition 009;101;1140-1144.
11 One ounce of walnuts provides 18g of total fat, 2.5g of monounsaturated fat, 13g of polyunsaturated fat, including 2.5g of alpha-linolenic acid, the plant-based omega-3.