Dieting Dangerously?

To some breast cancer patients, and to anyone else who worries about their health, dinner can sometimes seem dangerous.

"What's safe to put on the table today?" wonders Beth C., currently under treatment for early stage breast cancer.

"It's 'Russian Roulette' between the pesticides on vegetables, the hormones in meat, the junk in farmed fish, the pollutants in the water and air," Beth says.

"Going to the grocery store these days puts me in a panic."

Today's findings from the Nurses Health Study seem to only add to that panic. This new research suggests that red meat intake in pre-menopausal women seems to increase the risk of developing hormone-receptor positive (or ER+) breast cancer.

But don't run away from your grill just yet -- what the study actually found is a bit less scary. In reality, out of this large sample of women, those with ER+ breast cancer are more likely to eat red meat on a regular basis.

Interpreting the Results

The large-scale Nurses Health Study lets scientists think about how diet early in life can impact risk of disease later in life. The study isn't supposed to give any definitive answers, but it helps scientists pick up on trends in diet and disease that they might not otherwise notice.

Over 90,000 pre-menopausal nurses filled out several questionnaires about their diets and the foods they ate. Researchers followed the nurses for 12 years. Then they tracked who got breast cancer and who didn't. They found that the more red meat a pre-menopausal woman ate, the more likely it was that this woman also had ER+ breast cancer.

While scientists can suggest a connection between red meat and breast cancer, they can't exactly say that eating red meat ups your chances of ER+ breast cancer. The study wasn't specifically designed to settle this big red meaty question.

For example, the red meat eaters in this study differed from the non-red meat eaters in potentially important ways: red meat eaters were more likely to be current smokers, weigh more and consume more calories. Those differences make any conclusions a bit shaky.

Still, this study does help identify important questions to further consider: is there a connection between red meat and breast cancer, and if so, then what kinds of red meat are most closely associated with this higher risk?

Everyone -- not just women -- wants to know these answers.

What's on the Menu?

Hunger for information on safe foods -- voiced by my patients at the hospital and the millions of visitors at -- propelled us at to launch a new section on nutrition, as well as feature an Ask-the-Expert Conference this Wednesday evening 11/15/06 at 9:30 EST.

The interface between diet and disease leaves a lot of people with a lot of questions. Sometimes, diet has a clear effect on health. Other times, illness seems unfortunately unavoidable.

"I just don't know how I could've gotten breast cancer: I run miles every day, I'm thin and don't smoke, and I'm practically a vegetarian," says Melodie C., who's in a battle with metastatic breast cancer.

So what can women do to reduce their risk?

While there is no "magic bullet," there is still a lot each individual woman can do.

Variation (mix up your protein options: egg whites, beans, tofu, chicken, fish, meats), moderation and portion control (your protein portion need be no bigger than a deck of cards), balance and diversity (pick 5-9 vegetables and fruits per day of different colors: blueberries, peaches, broccoli, cauliflower, yellow squash).

Not smoking, limiting or avoiding alcohol consumption (fewer than 5 drinks/week), exercising 3-4 or more hours per week, following a low-fat diet and sticking to your ideal body weight are all important.

Buying organic -- and trying to lower your exposure to pesticides, fertilizers, and hormones in food -- is also likely to make a meaningful difference.

Dr. Marisa Weiss is President and Founder of