The new cabbage soup diet

Estrogen
The connection here is through estrogen, the female hormone that has been linked with tumour promotion. The relationship between estrogen and breast cancer, admittedly, is not a simply one. Laboratory studies have shown that estrogen, like many chemicals in the body, undergoes a variety of reactions after it is produced. Its metabolism, as these reactions are collectively called, can take two alternative routes. One produces 16-hydroxtyestrone, which seems to be the culprit in terms of stimulating the irregular multiplication of breast tissue cells. Alternatively, estrogen can be converted in into 2-hydroxyestrone, a compound that is relatively inert. Both of these conversions are governed by specific enzymes, levels of which can be affected by various factors. This is where indole-3-carbinol comes in. It stimulates the protective enzymes that take estrogen down the safe path, meaning that there will be less exposure of breast tissue to nasty 16-hydroxyestrone molecules.

That's pretty interesting stuff, but it's also pretty abstract for most of us. Probably not enough to persuade people to rush into the kitchen and start boiling cabbage. But wait. Mice develop fewer mammary tumours when exposed to indole-3-carbinol. Rats exhibit less endometrial cancer. But things get even more interesting when we discover that researchers have actually fed 400 milligram capsules of indole-3-carbinol to women on a daily basis (roughly equivalent to the amount in half a head of cabbage) and determined that it really did affect the way that estrogen was metabolized. Within two weeks the levels of 2-hydroxyestrone, the good stuff as it were, went way up. In fact, the levels rivaled those found in marathon runners, who are known to have a lower incidence of breast cancer.

Some evidence
So that's what happened to the pill poppers. But what about eating cabbage itself? Thanks to some Israeli research, we have an answer to that question as well. Eighty women on a kibbutz agreed to eat a diet high in cruciferous vegetables and submit their urine for analysis. The ratio of 2-hydroxyestrone to 16-hydroxyestrone in the urine increased, suggesting protection against breast cancer. It would be interesting to follow these women for a number of years and determine whether or not the breast cancer rate is actually lowered. There is a good chance that will happen, at least if we judge by some interesting epidemiological evidence from Germany and Poland.

Page 2 of 3

---

Excerpted from An Apple a Day: The Myths, Misconceptions and Outright Exaggerations about Diet, Nutrition and the Foods We Eat. Published by HarperCollins Publishers Ltd. Copyright 2007 by Dr. Joe Schwarcz. All rights reserved. Reprinted by permission of HarperCollins Publishers Ltd.