Better sex drive: According to researchers at a reputed American university, eating 75 gm of the nuts each day can increase a man's virility and the health of his sperm. The team found that men aged between 21-35, who regularly ate walnuts, had sperm with enhanced vitality and movement. Walnuts are rich in a natural plant source of omega-3, a type of fatty acid thought to be critical to sperm development.