"A recent study has found that Insulin-like growth factor present in dairy products may increase the chance of twinning. Specifically, the study found that vegan mothers (who exclude dairy from their diets) are one-fifth as likely to have twins as vegetarian or omnivore mothers, and concluded that "Genotypes favoring elevated IGF and diets including dairy products, especially in areas where growth hormone is given to cattle, appear to enhance the chances of multiple pregnancies due to ovarian stimulation." From 1980–97, the number of twin births in the United States rose 52%. This rise can at least partly be attributed to the increasing popularity of fertility drugs like Clomid and procedures such as in vitro fertilization, which result in multiple births more frequently than unassisted fertilizations do. It may also be linked to the increase of growth hormones in food."
I feel sad that (apparently) Vegan mothers have less chance of having the miracle of twins!
Very interesting, and seems to disprove any "oh, the hormones we give to animals have no effect on humans" garbage.