Adding a handful of walnuts to a man’s daily diet might just increase the chance of pregnancy for couples with fertility problems. Scientists attribute male infertility as the central issue in 30 to 50 percent of the 70 million couples worldwide experiencing such difficulties.

Researchers at the University of California, Los Angeles, investigated whether increasing intake of the polyunsaturated fatty acids found in fish, flax seed and walnuts that are critical for sperm maturation and membrane function would increase sperm quality in men consuming a typical Western-style diet. They found that less than three ounces of walnuts added to a man’s daily diet improved sperm strength, size and motility (swimming ability). The men eating the walnuts also showed fewer chromosomal abnormalities in their sperm.