To print: Select File and then Print from your browser's menu --------------------------------------------------------------------------------------- Title: AACR: Little Impact With High-Fibre, Low-Fat Diet On Ovarian Hormone Levels URL: http://www.pslgroup.com/dg/1F64C6.htm Doctor's Guide March 27, 2001
By Cameron Johnston Special to DG News
NEW ORLEANS, LA -- March 27, 2001 -- A new study presented yesterday at the annual meeting of the American Association for Cancer Research may challenge the idea that a high dietary fat contributes to breast cancer in women.
According to Dr. Peter Gann, an assistant professor in the department of preventive medicine at Northwestern University Medical School, in Chicago, Illinois, endogenous exposure to reproductive hormones has been suggested as a risk factor for a woman developing breast cancer. Since modifying one's intake of dietary fats was thought to reduce the production of these hormones, it was also felt that lowering fat intake could reduce cancer risk.
To date, there has been little data from randomized trials to indicate that there is any effect from changing fat and fibre consumption on hormone levels in young women.
In this study, 213 healthy women were randomized to either a low-fat, high-fibre diet (n=106) or no dietary changes (n=107) for a period of one year.
"This relates to the possibility that eating a low-fat pattern might reduce the risk of breast cancer, and this specifically addresses the question of whether it would do so by reducing the ovarian hormones that are produced in younger women," said Dr. Gann said in an interview with Doctor's Guide. "That is only one of the mechanisms by which dietary patterns might affect breast cancer risk but it is one that is considered very important," he said.
The women received 20 percent of their total caloric intake from fats, total fibre intake was 25-30 g/day, they were encouraged to have more than eight servings of fruit and vegetables per day, 60-65 kCal of complex carbohydrates and 15-20 kCal of proteins. They were specifically encouraged by the dietitian not to attempt to lose weight, or to modify their daily caloric intake.
The women had blood work done, breast fluids collected and urine tests done seven days after their luteanizing peak at baseline and again during their fourth monthly cycle and their 12th monthly cycle.
The study revealed that there was a mean monthly reduction in breast estradiol of 7.5 percent, which Dr. Gann said is in the predominant form of estrogen. The mean estradiol level was 105 pg/mL at baseline, and fell to 97 pg/mL at cycle 12 in the study group. In the usual diet group, the overall change in estradiol was 0.9 pg/mL.
Sex hormone-binding globulin (SHBG) was similar in controls (43.96 pg/mL) and the intervention group (47.36 pg/mL).
The results did not vary according to age, body mass index or baseline hormone levels.
"What we are seeing here is that in the absence of weight change, and with just a change in composition of the diet, there does not appear to be a difference in hormones," Dr. Gann said.
On the basis of these findings, there did not appear to be a link between hormone levels and diet. However, he said, the dilemma is that, in order to pursue this further, it would be necessary to consider a diet that is more radical, lower in fats and higher in fibre, and that diet might not be sustainable by most women.
One of the important messages is that this is a study of diet composition, and means women who adopt this pattern will lose some weight, although the dietitians were not aiming specifically for weight-loss. Moreover, Dr. Gann said, published literature shows that as much as 25 to 30 percent of breast cancers which occur in older, postmenopausal women may be associated with weight gain while they were adults and this should be considered a significant risk factor for developing the disease.
Current theories also suggest that in order for dietary modifications to be truly effective, they should be started when the young women are entering puberty -- if not before -- and their breast tissue is just starting to form and to be differentiated. --------------------------------------------------------------------------------------------- Copyright © 1999 P\S\L Consulting Group Inc. All rights reserved. Republication or redistribution of P\S\L content is expressly prohibited without the prior written consent of P\S\L. P\S\L shall not be liable for any errors, omissions or delays in this content or any other content on its sites, newsletters or other publications, nor for any decisions or actions taken in reliance on such content. --------------------------------------------------------------------------------------------- This news story was printed from *Doctor's Guide to the Internet* located at http://www.docguide.com --------------------------------------------------------------------------------------- Return to News Story Page This site is maintained by webmaster@pslgroup.com Please contact us with any comments, problems or bugs. All contents Copyright (c) 1998 P\S\L Consulting Group Inc. All rights reserved.