Diet and Breast Cancer Risk: What’s the Connection?

Article date: September 13, 2010

By: Rebecca V. Snowden

There are some things we know can help reduce breast cancer risk: staying at a healthy weight, being physically active, taking certain medications. But is there any connection between your diet and your risk of breast cancer?

Despite being an area of intense research, the role of diet in breast cancer risk remains unclear.

Low fat = Low breast cancer risk?

Several studies have found that breast cancer is less common in countries where the typical diet is low in total fat. However, in studies of women in the US, researchers haven’t been able to show that eating less fat helps reduce breast cancer risk, nor have they have been able to show that eating a high fat diet increases risk.

But it’s clear that calories do count, and fat is a major source of these.

Foods from animal sources are the biggest contributors of total fat and saturated fat in the American diet. For this reason, the American Cancer Society recommends limiting consumption of meats, especially high-fat ones. Although researchers haven’t been able to show a direct link to breast cancer, consumption of meat--especially red meats--has been linked to other cancers, most notably colon and prostate.

And eating a high-fat diet can lead to being overweight or obese – a known breast cancer risk factor.

Pass the veggies

Eating a diet rich in fruits and vegetables is associated with good health, but can it help lower your breast cancer risk? Researchers can’t say for sure. No study has been able to definitely link the two.

As for claims that eating a certain vegetable or fruit will lower your risk, there’s no hard evidence. Nutrients in certain vegetables and fruits, known as antioxidants, appear to protect the body against tissue damage and may lower cancer risk, but again, the research is far from definitive.

However, fruits and vegetables are naturally low in calories and provide you with nutrients and plenty of fiber, helping keep your weight in check, which in turn may lower your cancer risk. The American Cancer Society recommends you aim for at least 5 servings of fruit and vegetables each day.

The scoop on D

You get vitamin D two ways: by exposing your skin to ultraviolet (UV) radiation from the sun and through your diet, typically from milk, cereals, and supplements.

There’s a growing body of evidence that vitamin D may have helpful effects on some types of cancer, including cancers of the colon, prostate, and breast, but research on the association between vitamin D and breast cancer risk has been conflicting. Some studies have found a slight association; others have found little benefit from or even a higher risk with vitamin D intake.

However, a recent study found that women with early-stage breast cancer who were vitamin D deficient were more likely to have their cancer recur in a distant part of the body and had a poorer outlook. More research is needed to confirm this finding, and it is not yet clear if taking vitamin D supplements would be helpful. Still, you may want to talk to your doctor about testing your vitamin D level to see if it is in the healthy range.

Watch the alcohol

Regularly having even a few alcoholic drinks per week is linked to a higher risk of breast cancer in women, especially in women who do not get enough folate.

If you do drink, the American Cancer Society recommends you limit yourself to no more than 1 drink per day for women and 2 drinks per day for men. If you’re at high risk for breast cancer, you may want to consider not drinking any alcohol.
What counts as a drink?

• 12 ounces of beer
• 5 ounces of wine
• 1.5 ounces of 80-proof distilled spirits

Do your body good

Studies continue to explore lifestyle factors and habits that may affect breast cancer risk. There are ongoing studies looking at the effect of exercise, weight gain or loss, and diet.

In the meantime, you can certainly help improve your overall health by balancing calorie intake with physical activity to get to or stay at a healthy weight; getting at least 30 minutes of exercise on 5 or more days per week; and following the dietary guidelines discussed above. Regular mammograms and breast exams are also important to help find breast cancer early, if it does develop.

For help with any of these goals, be sure to check out the American Cancer Society's new program, Choose You, designed to inspire women to take action and put their health first in order to stay well and help prevent cancer. Register at chooseyou.com, and you'll have access to online support and tools such as a calorie calculator, virtual dietitian, nutrition and activity quiz, prevention and early detection videos, and a desktop helper with daily health tips.