The soybean, also known as the soya bean, is a plant native to
Eastern Asia. It is often used in the production of vegetarian-
safe foods, such as soy milk or infant formula. It is also a
source of vitamin E. Soy milk is used as a mild alternative for
people suffering from lactose intolerance or chronic heartburn,
and soybeans are the primary ingredient in a foodstuff called
tofu, frequently used in East Asian cuisine. Soy sauce, made
from fermented soya beans, is important as a condiment and
ingredient in East Asian cooking. Raw soybeans (known as
edamame) are also used as a feed for livestock, especially pigs
and poultry. Soy has become a major crop in the United States
but is not as commonly cultivated in Africa, Europe or South
America. Soy contains large quantities of phytoestrogens, which
can have similar effects to human estrogen. Feeding soy milk to
babies and children can interfere with the endocrine system,
making girls reach puberty much earlier and making boys take
years for puberty. In excess, soy