A new study finds that women who consume animal products, specifically dairy, are five times more likely to have twins than those who do not, and the reason may have to do with the growth hormones fed to cows. Meanwhile, other studies show that identical twins are not as identical as we once thought they were.
A growth protein called IGF is released from the liver of animals and humans in response to growth hormones. IGF circulates in the blood gets into an animal’s milk. When women drink milk or eat meat, the IGF increases ovulation and might also help embryos survive in the early stages of development. The concentration of IGF in the blood is about 13% lower in vegan women than in women who consume dairy.