Protection against certain cancers. Naturally occurring chemicals (indoles,
isothiocyanates, glucosinolates, dithiolethiones, and phenols) in
cauliflower, Brussels sprouts, broccoli, cabbage, and other cruciferous
vegetables appear to reduce the risk of some cancers, perhaps by
preventing the formation of carcinogens in your body or by blocking
cancer-causing substances from reaching or reacting with sensitive body
tissues or by inhibiting the transformation of healthy cells to malignant
All cruciferous vegetables contain sulforaphane, a member of a family
of chemicals known as isothiocyanates. In experiments with laboratory
rats, sulforaphane appears to increase the body's production of phase-2
enzymes, naturally occurring substances that inactivate and help eliminate
carcinogens. At the Johns Hopkins University in Baltimore, Maryland, 69
percent of the rats injected with a chemical known to cause mammary cancer
developed tumors vs. only 26 percent of the rats given the carcinogenic
chemical plus sulforaphane.
In 1997, Johns Hopkins researchers discovered that broccoli seeds and
three-day-old broccoli sprouts contain a compound converted to
sulforaphane when the seed and sprout cells are crushed. Five grams of
three-day-old broccoli sprouts contain as much sulforaphane as 150 grams
of mature broccoli. The sulforaphane levels in other cruciferous
vegetables have not yet been calculated.
Adverse Effects Associated with Cauliflower
Enlarged thyroid gland (goiter). Cruciferous vegetables, including
cauliflower, 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 condition or are taking thyroid medication.
Intestinal gas. Bacteria that live naturally in the gut degrade the
indigestible carbohydrates (food fiber) in cauliflower, producing
intestinal gas that some people find distressing.
Anticoagulants. Cauliflower contains vitamin K, the blood-clotting
vitamin produced naturally by bacteria in our intestines. Additional
intake of vitamin K may reduce the effectiveness of anticoagulants (warfarin,
Coumadin, Panwarfin), requiring larger-than-normal doses to produce the
False-positive test for occult blood in the stool. The active
ingredient in the guiac slide test for hidden blood in feces is
alphaguaiaconic acid, a chemical that turns blue in the presence of blood.
Cauliflower contains peroxidase, a natural chemical that also turns
alphaguaiaconic acid blue and may produce a positive test in people who do
not actually have blood in the stool.