The older that such fish become, the more mercury they may have absorbed. Anything that eats these fish within the food chain also consumes the higher level of mercury that the fish have accumulated. This process explains why predatory fish such as swordfish and sharks or birds like osprey and eagles have higher
The goal, then, when it comes to having a boy is to increase the likelihood that a Y chromosome sperm reaches the egg first. Many medical researchers believe that Y chromosome sperm are faster swimmers, but that X chromosome sperm have more endurance.
Some studies point to zinc as the magic fertility bullet. This type of research claims that the consumption of at least 15 mg of zinc a day can increase semen and testosterone production in men and ovulation and fertility in women, report the editors at Fertility.com.