Honored Contributor
Posts: 18,752
Registered: ‎03-09-2010

New Report: Moderate Soy Consumption OK For Breast Cancer Survivors

This has been a subject of interest on Viewpoints for many members.

To follow is most of the information from the article. If requested, I'll c&p the entire report.

From Medscape News:


November 7, 2011 (Washington, DC) — It is all right for breast cancer survivors to consume moderate amounts of soy foods, Bette Caan, PhD, a senior research scientist who specializes in nutritional epidemiology at the Division of Research at Kaiser Permanente Northern California in Oakland told attendees here at the American Institute for Cancer Research (AICR) Annual Research Conference 2011 on Food, Nutrition, Physical Activity and Cancer in a session on cancer treatment and survivorship.

Soy foods can either increase the risk for breast cancer progression or decrease the risk, she observed. Evidence suggests that lifetime endogenous estrogen exposure increases the risk for breast cancer. So people were afraid to tell breast cancer survivors that it was okay to eat soy.

Clinicians have several options based on the epidemiologic literature, and some routinely advise against soy in the diet of patients with breast cancer, Dr. Caan noted, "and I don't think the current science supports that at all."

No Evidence of Harm

After reviewing the 7 epidemiologic studies, Dr. Caan said there was no evidence that soy is harmful for women with breast cancer, and pointed out that 6 of the 7 studies demonstrate some type of benefit.

On the basis of the lack of harm and the benefits reported in the studies she cited, clinicians might want to recommend that patients with breast cancer begin eating whole soy foods to treat breast cancer, but she cautioned that she doesn't think existing data were strong enough to justify that.

"What I do think is that they could adopt a stance of permitting use in patients who want to begin eating reasonable amounts of soy foods or for whom soy foods already represent a normal part of their diet," Dr. Caan said.

The data support this option, and she said they were consistent with the American Cancer Society (ACS) position.

She added 1 caveat: to avoid concentrated sources of soy, such as pills, powders, or supplements containing high amounts of isoflavones, because data are lacking on the risks and benefits. "We still need to proceed with caution," she said.