3 Myths (and 3 Truths) About Diet and Breast Cancer

Setting the facts straight about the relationship between diet and the causes of breast cancer

Do certain foods increase your risk of breast cancer? Are there foods that can help prevent it? Myths about diet and breast cancer abound but before you start overhauling your diet, let’s sort fact from fiction.

Myth #1: Dairy causes breast cancer. Over the last 10 years, dozens of studies — several of them involving thousands of subjects — have investigated the possible relationship between dairy consumption and breast cancer. Researchers have failed to turn up any link between dairy and breast cancer risk. In a few of the studies, dairy consumption was actually linked to a slight reduction of risk.

Myth #2: Soy causes breast cancer. Soy consumption appears to reduce the risk of breast cancer in the general population. But researchers worried that the estrogen-like compounds in soy pose a threat for women who already had cancer. Several recent studies have found that moderate soy consumption appears to have no adverse effect on breast cancer survivors — and may even slightly reduce the risk of recurrence.

Myth #3: Sugar feeds cancer cells. Another common myth is that cancer cells "feed on sugar." This is simply not true. All cells use glucose (or sugar) for fuel. But sugar does not make cancer cells grow faster — and a lack of sugar does not stop them from growing. Studies have found no consistent link between sugar consumption and breast cancer.

The truth is that cutting out dairy or soy isn’t going to do you any harm. And there are a lot of other good reasons to limit the amount of sugar in your diet. But if you’re interested in reducing your risk of breast cancer, be sure you’re not overlooking the things that will have the biggest impact.

The 3 Most Important Things You Can Do to Reduce Your Risk of Breast Cancer

1. Lose Weight (If You Need To)

Being overweight is one of the strongest and most consistent risk factors for breast cancer — particularly in women who have gone through menopause. Having more body fat increases your circulating estrogen levels, which contribute to cancer risk. Educate yourself on how to take off extra weight and how to find a diet that will work for you.

2. Exercise Regularly

Even if you can maintain a healthy weight without exercising, regular exercise further reduces your risk of breast cancer by lowering the levels of circulating estrogen in your body. Among cancer survivors, regular exercise has been shown to cut mortality risk in half. We’re not talking about ironman competitions or 100-mile bike rides. You can substantially reduce your risk of breast cancer by taking a brisk 30-minute walk every day.

3. Drink Moderately or Not at All

Although it’s not completely clear how or why alcohol increases cancer risk, the evidence of a link between drinking and breast cancer is quite convincing. Even one drink a day is linked to a slight increase in risk. Higher consumptions levels bump your risk up dramatically. If you regularly consume alcohol and you’re at all concerned about breast cancer, this is one habit you may want to give serious thought to — especially if you are overweight and/or sedentary.

If only there were a magic bullet — a special diet, a superfood, a cancer-killing recipe — that would ensure that none of us would ever have to worry about breast cancer (or any cancer) again. Short of that, let’s do the best we can to take good care of ourselves and take some comfort in the fact that, while there are no guarantees, the same habits that lower our cancer risks also reduce the risk of lots of other diseases and help us enjoy life to the fullest!


Monica Reinagel, M.S., L.D./N., is a board-certified, licensed nutritionist and a professionally trained chef. Read more from Monica about health, cooking, and tips on Nutrition Diva