According to a new study, women who consume animal products, specifically dairy, are five times more likely to have twins than those who follow a vegan diet. The growth hormone IGF, which is routinely fed to cows, is the primary suspect. Research shows that vegan women have approximately a 13 percent lower level of IGF in their blood than women who consume dairy.
Several studies are finding that diet does play a role in fertility, or infertility as the case may be. Below are somewhat contradicting studies on the topic of milk and fertility.