Thursday, January 19, 2006
Soy May Help Prevent Breast Cancer in Older Women
MONDAY, Jan 16 (HealthDay News) -- A diet rich in soy, with its natural plant estrogens or isoflavones, may help protect postmenopausal women with relatively high levels of estrogen from getting breast cancer, preliminary research suggests.
Women past menopause who have low estrogen levels probably won't derive the same risk reduction, but they can probably be assured the soy isn't harmful in terms of breast cancer risk, said Charles E. Wood, an instructor of pathology at Wake Forest University.
"If you have high estrogen, the isoflavones could block the adverse effects of your body's own estrogen [on the breast tissue,]" said Wood, who based his views on his team's study involving postmenopausal monkeys, published in the Jan. 15 issue of Cancer Research.
Wood's study adds new fuel to the ongoing debate surrounding soy's effect on cancer risk. "There's been a good deal of confusing information, particularly with soy's effect on [breast] cancer risk," said Wood.
"Most population-based studies have found that women who consume lots of soy are less likely to develop breast cancer," he said. "A number of studies have been done, and they generally show a positive effect [of soy] or no effect."
But in lab studies, Wood said, isoflavones from soy -- which have a structure similar to estrogen -- have been found to stimulate breast cancer cells grown in a petri dish and induced estrogen-like effects.
"Our hypothesis was that the amount of estrogen in the body may help determine whether soy was having good or bad effects," he said. "If you have very low estrogen, high doses of soy could have adverse estrogen-like effects on your reproductive tissue. If you had high estrogen, the isoflavones could block the adverse effects of your body's own estrogen."
"That was our working hypothesis." Wood and his team used a postmenopausal monkey model. They first selected out a high-estrogen group of monkeys and a low-estrogen group. Next, they fed each group four different diets for 16 weeks each, along with a high or a low dose of estrogen.
The diets included either no isoflavones; 60 milligrams of isoflavones (similar to the typical Asian diet); 120 milligrams (highest amount that can be obtained via diet alone); or 240 milligrams (levels that must be obtained via supplements).
Continued at Forbes.com
Women past menopause who have low estrogen levels probably won't derive the same risk reduction, but they can probably be assured the soy isn't harmful in terms of breast cancer risk, said Charles E. Wood, an instructor of pathology at Wake Forest University.
"If you have high estrogen, the isoflavones could block the adverse effects of your body's own estrogen [on the breast tissue,]" said Wood, who based his views on his team's study involving postmenopausal monkeys, published in the Jan. 15 issue of Cancer Research.
Wood's study adds new fuel to the ongoing debate surrounding soy's effect on cancer risk. "There's been a good deal of confusing information, particularly with soy's effect on [breast] cancer risk," said Wood.
"Most population-based studies have found that women who consume lots of soy are less likely to develop breast cancer," he said. "A number of studies have been done, and they generally show a positive effect [of soy] or no effect."
But in lab studies, Wood said, isoflavones from soy -- which have a structure similar to estrogen -- have been found to stimulate breast cancer cells grown in a petri dish and induced estrogen-like effects.
"Our hypothesis was that the amount of estrogen in the body may help determine whether soy was having good or bad effects," he said. "If you have very low estrogen, high doses of soy could have adverse estrogen-like effects on your reproductive tissue. If you had high estrogen, the isoflavones could block the adverse effects of your body's own estrogen."
"That was our working hypothesis." Wood and his team used a postmenopausal monkey model. They first selected out a high-estrogen group of monkeys and a low-estrogen group. Next, they fed each group four different diets for 16 weeks each, along with a high or a low dose of estrogen.
The diets included either no isoflavones; 60 milligrams of isoflavones (similar to the typical Asian diet); 120 milligrams (highest amount that can be obtained via diet alone); or 240 milligrams (levels that must be obtained via supplements).
Continued at Forbes.com
