On Food and Cooking

of prostate cancer and heart disease. However,
some studies suggest that phytoestrogens can
worsen preexisting breast cancer, and are
protective against some cancers only when
consumed during adolescence. Our
understanding of phytoestrogens is still very
incomplete. It’s too early to say whether
soybeans are more beneficial to human health
than any other seed, or whether it’s a good
idea to eat them often.
Saponins are soap-like defensive
compounds that have a water-soluble end and
a fat-soluble end, so they can act as
emulsifiers and foam stabilizers. They’re one
of the reasons that a pot of soybeans boils
over so readily! Soybeans are a rich source of
saponins, which may make up 5% of their
total weight, about half of which is in the
hulls. Some plant saponins are so strong that
they damage our cell membranes. Soy
saponins are gentler, and bind to cholesterol
so that the body can’t absorb it efficiently.