The New Complete Book of Food
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 verify whether taking folic acid supplements reduces the
risk of cardiovascular disease.
Vision protection. In 2004, the Johns Hopkins researchers updated their findings on sulfora-
phane to suggest that it may also protect cells in the eyes from damage due to ultraviolet
light, thus reducing the risk of macular degeneration, the most common cause of age-related
vision loss.Adverse Effects Associated with This Food
Enlarged thyroid gland (goiter). Cruciferous vegetables, including brussels sprouts, contain
goitrin, thiocyanate, and isothiocyanate. These chemicals, known collectively as goitrogens,
inhibit the formation of thyroid hormones and cause the thyroid to enlarge in an attempt to
produce more. Goitrogens are not hazardous for healthy people who eat moderate amounts
of cruciferous vegetables, but they may pose problems for people who have a thyroid condi-
tion or are taking thyroid medication.
Intestinal gas. Bacteria that live naturally in the gut degrade the indigestible carbohydrates
(food fiber) in brussels sprouts and produce gas that some people find distressing.Food/Drug Interactions
Anticoagulants Brussels sprouts are rich in vitamin K, the blood-clotting vitamin produced
naturally by bacteria in the intestines. Consuming large quantities of this food may reduce
the effectiveness of anticoagulants (blood thinners) such as warfarin (Coumadin). One cup
of drained, boiled brussels sprouts contains 219 mcg vitamin K, nearly three times the RDA
for a healthy adult.