The New Complete Book of Food
Preprocessing. Preprocessed dried soybeans have already been soaked. They take less time
to cook, but they are lower in B vitamins.Medical Uses and/or Benefits
Lower risk of some birth defects. Up to two of every 1,000 babies born in the United States
each year may have cleft palate or a neural tube (spinal cord) defect due to their mothers’
not having gotten adequate amounts of folate during pregnancy. The current RDA for folate
is 180 mcg for a woman and 200 mcg for a man, but the FDA now recommends 400 mcg
for a woman who is or may become pregnant. Taking a folate supplement before becoming
pregnant and continuing through the first two months of pregnancy reduces the risk of cleft
palate; taking folate through the entire pregnancy reduces the risk of neural tube defects.
Possible lower risk of heart attack. In the spring of 1998, an analysis of data from the records
for more than 80,000 women enrolled in the long-running Nurses’ Health Study at Harvard
School of Public Health/Brigham and Women’s Hospital, in Boston, demonstrated that a diet
providing more than 400 mcg folate and 3 mg vitamin B 6 daily, either from food or supple-
ments, might reduce a woman’s risk of heart attack by almost 50 percent. Although men
were not included in the study, the results were assumed to apply to them as well.
However, data from a meta-analysis published in the Journal of the American Medical
Association in December 2006 called this theory into question. Researchers at Tulane Univer-
sity examined the results of 12 controlled studies in which 16,958 patients with preexisting
cardiovascular disease were given either folic acid supplements or placebos (“look-alike” pills
with no folic acid) for at least six months. The scientists, who found no reduction in the risk
of further heart disease or overall death rates among those taking folic acid, concluded that
further studies will be required to ascertain whether taking folic acid supplements reduces
the risk of cardiovascular disease.
Lower cholesterol levels. A 1997 meta-analysis of 38 studies with more than 730 volunteers
by James Anderson of the Metabolic Research Group at the Veterans Administration Medical
Center and the University of Kentucky in Lexington demonstrates that substituting soy pro-
tein for animal proteins can lead to an average 9.3 percent decline in total cholesterol, a 12.3
percent decline in levels of low-density lipoproteins (the fat and protein particles that carry
cholesterol into your arteries), and a 2.4 percent rise in HDL levels. People whose original
cholesterol readings are “high” (250–289 mg/dl) are likely to see a greater decrease, as much
as 24 percent lower total cholesterol.
There are currently two theories to explain how beans reduce cholesterol levels. The
first theory is that the pectins in the beans may form a gel in your stomach that sops up fats
and keeps them from being absorbed by your body. The second is that bacteria in the gut may
feed on the bean fiber, producing short-chain fatty acids that inhibit the production of choles-
terol in your liver. Whether soy’s isoflavones affect cholesterol levels remains unanswered.
Lower levels of homocysteine. Homocysteine is an amino acid produced during the diges-
tion of proteins. In 1998, the American Heart Association announced that high levels of