Irritable Bowel Syndrome Message Boards | Higher Fiber Shown To Reduce Estrogen Levels

Higher Fiber Shown To Reduce Estrogen Levels

October 19, 2004

An international team has demonstrated that women with a higher intake of dietary fiber have lower circulating estrogen levels, a factor associated with lower risk of breast cancer. They say their findings, which offer direct evidence of the association between fiber and the hormone, could lead to a dietary strategy for lowering a woman's risk of breast cancer.

Breast cancer rates have risen in recent decades to become the most common cancer among women in the European Union and US. Britain has one of the highest breast cancer death rates in the world, according to Breast Cancer Research, with one woman in nine developing the disease during her lifetime.

There have already been several studies investigating the relationship between dietary fiber and breast cancer but researchers have not been able to show a true and unequivocal cause-and-effect relationship between fiber and breast cancer risk.

In a new study, researchers from the Keck School of Medicine of the University of Southern California in Los Angeles, the University of Hawaii in Honolulu, and the University of Helsinki in Finland examined blood estrogen levels in around 250 Mexican-American women, an ethnic group in which dietary fiber intake is higher on average than in most other populations.

"Latinas enrolled in the Multiethnic Cohort Study have lower breast cancer rates than any major racial/ethnic group in the US. Even after adjusting for known risk factors, their incidence rate is still 20 percent less than white women, who have been the focus of the majority of earlier research and whose dietary fiber intake is generally not that high," explained the study first author Kristine Monroe, a postdoctoral fellow in the Keck School's department of Preventive Medicine.

Dietary fiber intake was quantified by a food frequency questionnaire administered at the time of the blood draw and by using biomarkers of dietary fiber intake found in the blood samples.

Speaking yesterday at the American Association for Cancer Research (AACR) conference, 'Frontiers in Cancer Prevention Research', the researchers said they found the two female hormones estrone and estradiol dropped sharply as dietary fiber intake increased.

In addition, as dietary fat intake increased in the women studied, so did the hormone levels. "However, when dietary fiber and fat are both included in the statistical model, only dietary fiber remains a significant predictor of hormone levels," said Monroe.

The next step is to see if a higher intake of dietary fiber in these women leads to a lower incidence of breast cancer, she added. "This study provides clear evidence of an association between dietary fiber intake and circulating hormone levels in postmenopausal Latina women and potentially provides a dietary means for lowering a woman's risk of breast cancer," concluded the researchers.

Earlier this year a Swedish team reported that postmenopausal women in the highest quintile of fiber intake had a 40 percent lower risk of breast cancer than those with the lowest. Combining high fiber with a low fat diet reduced the risk even further.

http://www.nowfoods.com/?action=itemdetail&item_id=42322&TPL_NAME=printview.tpl&CSPID=b1bea10afacfa3231fb97d01d0ebe123

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Heather is the Administrator of the IBS Message Boards. She is the author of Eating for IBS and The First Year: IBS, and the CEO of Heather's Tummy Care. Join her IBS Newsletter. Meet Heather on Facebook!

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