Welcome news to the estimated 70 million couples who experience forms of infertility, with an estimated 50 percent of whom attributable to the male partner. Biology of Reproduction's Papers-in-Press announced that eating 75 grams of walnuts a day improves the "vitality, motility, and morphology of sperm in healthy men aged 21 to 35."
Some studies have speculated that the quality of sperm in industrialized nations has declined, due to factors like pollution, poor diet/lifestyle habits.
But good news, guys: you can boost your sperm quality by consuming more polyunsaturated fatty acids (PUFAs), the best sources of which are fish and fish oil supplements, flax seed, and... walnuts.
So not the greatest news for men with tree nut allergies. Still, the study found that of more than a hundred healthy men between the ages of 21 and 35, over half who ate 75 grams of walnuts per day significantly improved the health of their sperm, reporting increased levels of omega-6 and omega-3 (ALA) fatty acids. (Researchers agreed on 75 grams, as this amount is enough to alter blood lipid levels without causing weight gain.)
So if you're struggling to make a baby with the man you love, sneak a few walnuts into his lunch. Hey, it can't hurt, right?