Plant Estrogens Low in Older Womens
Diets By Judy
September 28, 2001
There is evidence that natural, estrogen-like compounds in
soybeans and many other plant foods may reduce hot flashes and vaginal dryness
and increase bone density in women after menopause. But a careful inspection of
the diets of nearly 1,000 older women in Massachusetts found their average
intake of these phytoestrogens to be less than one milligram (mg) daily.
Thats only 1 to 5 percent of the phytoestrogen intake
reported for Asian populations. Soybeans and soy protein products like tofu are
concentrated sources of phytoestrogens and are common in Asian diets. By
contrast, foods common in Western diets are far lower in these compounds.
Studies suggest that body cells respond to plant estrogens as if
they were weaker versions of the human hormone. So consuming more of these
estrogen-mimicking compounds may help compensate for the loss of estrogen
naturally as women age.
Researchers at the Jean
Mayer USDA Human Nutrition Research Center on Aging at Tufts University in
Boston collaborated on the study with colleagues at the
University Medical Center Utrecht in
University School of Medicine and the
University of Helsinki and
Folkhalsan Research Center in Finland.
They estimated intakes of the three classes of
phytoestrogens--isoflavones, lignans and coumestans--from food frequency
questionnaires filled out by 964 postmenopausal, Caucasian women participating
(Mass.) Offspring Study.
In contrast to Asian populations, the U.S. women got the bulk of
their phytoestrogens--nearly 0.6 mg--from fruit, such as berries, citrus,
apples and melon, in the form of secoisolariciresinol. The compound is one of
the lignans, which are most concentrated in flaxseed.
The better known isoflavones--genestein, daidzein and
formononetin--provided about one-fourth of the phytoestrogens in the
womens diets. And these came mostly from beans and peas rather than from
soy products, according to study leader Paul Jacques, who heads nutritional
epidemiology research at the USDA center.
The third class of phytoestrogens, coumestans, were barely
detectable in the womens diets.
The Boston center is funded by the
Agricultural Research Service,
USDAs chief scientific agency.