High Carb Diets May Raise Breast Cancer Risk

[Vance]

NEW YORK (Reuters Health) - Diets that have a high "glycemic index" -- that is, they produce high blood sugar levels -- may increase the risk of breast cancer among postmenopausal women who've used hormone replacement therapy (HRT), study results suggest.

The link may be stronger among those who do not engage in vigorous physical activity.

Typically, high glycemic index diets include a lot of sugars and refined starches and carbohydrates, which produce a rapid rise in blood glucose levels.

"Given evidence of a positive association between (high insulin levels) and breast cancer risk, we felt it conceivable that this reflects an underlying association with high glycemic index diets," Dr. Stephanie A. Navarro Silvera from Albert Einstein College of Medicine in New York noted in comments to Reuters Health.

Silvera and her colleagues used data from a large group of 49,613 Canadian women to examine breast cancer risk in association with overall glycemic index and dietary carbohydrate and sugar intake.

During a follow-up period of 16 years, 1,461 women developed breast cancer.

In the overall study population, the risk of breast cancer was not related to glycemic index or sugar and total carbohydrate intake, the team reports in the International Journal of Cancer.

However, in postmenopausal women, diets with a high glycemic index raised the risk of breast cancer by 87 percent. In premenopausal women, such diets actually cut the risk by 22 percent.

The association between glycemic index and breast cancer risk in postmenopausal women was slightly stronger among women reporting no vigorous physical activity, among those with a history of HRT use, and among those of normal weight.

These results require confirmation in other studies, Silvera and colleagues emphasize in their report.

SOURCE: International Journal of Cancer, April 20, 2005.

Source: http://maconareaonline.com/news.asp?id=10387
Another source: http://www3.interscience.wiley.com/cgi-bin/abstract/109859007/ABSTRACT (Scientific information)

 

[deafdyke]

Actually I thought that the highest risk for breast cancer was not breastfeeding!

 

[Vance]

Actually I thought that the highest risk for breast cancer was not breastfeeding!

Sorry but I am bit confusing by that statement. You mean, women may will get the breast cancer if they weren't breastfeeding?

 

[Levonian]

No, what she means is that women who have never had children are at a far higher risk of contracting breast cancer than are women who have had children. And the younger the woman is when she has her first child, the lesser the risk is. This isn’t theory—it’s been amply demonstrated through epidemiological proof. The reason for this is easy to understand. Breast tissue in a woman who has never had children differentiates every month in preparation for possible lactation. If pregnancy doesn’t occur, the tissue reverts back to its undifferentiated state. After a first pregnancy, the differentiation does not reverse, and the tissue stays permanently primed for lactation. So there is a far lesser risk of replication errors in the DNA of a woman who has had a child. A woman who hasn’t had a child typically undergoes several hundred redundant differentiations of her breast tissue during her life, which astronomically increases the probability of a cellular replication error, and subsequent neoplasia.

 

[Vance]

Ahhh, gotcha. Many thanks for excellent explanation! That does make sense.