If you have high cholesterol, your doctor has probably warned you that you're at an increased risk of heart disease. Now it appears that women with high cholesterol may have another health worry: breast cancer.

Obesity and high cholesterol are linked to an increased breast cancer risk in postmenopausal women, according to a study published in the journal Science.

The Link Between Obesity, High Cholesterol, and Breast Cancer

Research has previously shown that obesity can up cancer risk. Overweight individuals produce more estrogen than people who aren't overweight, and it is known that exposure to estrogen can increase your risk of breast cancer, explains Stephanie Bernik, MD, chief of surgical oncology at the North Shore-LIJ Cancer Institute at Lenox Hill Hospital in New York City. Thus, women who take hormone replacement therapy, have late menopause, or start getting their periods at an early age have an increased risk of cancer, she says.

In the new study, conducted at Duke University Medical Center, mice that ate a high-fat diet were compared to mice on a normal diet. The mice on a high-fat diet had increased blood levels of 27HC, a substance that mimics estrogen. (27HC is not cholesterol, but a byproduct of cholesterol.) What's more, these mice had tumors that were 30 percent larger than in the mice fed a normal diet, according to the researchers, and their tumors also were more likely to spread.

"This study is saying that high cholesterol, at least in animal studies, can increase breast cancer risk," Bernik explains.

Can Cholesterol-Lowering Drugs Prevent Cancer?

According to Sparano, using cholesterol-lowering drugs called statins in certain individuals may modify the risk of breast cancer. "This study provides further evidence warranting the use of statins," he says.

However, Bernik stresses it's not recommended that a woman start taking statins based on this study. "More research needs to be done first," she says. Specifically, researchers "need to compare the incidence of breast cancer in women who have high cholesterol and who take statins with women who have high cholesterol and don't take statins."

In the meantime, there are a variety of other measures you can take to reduce breast cancer risk:

  • Maintain a normal weight
  • Don't smoke
  • If you drink, cut down on alcohol
  • Exercise. Aim for at least 150 minutes per week or moderate aerobic activity or 75 minutes of vigorous aerobic activity, and do some strength training at least twice a week.

Stephanie Bernik, MD, reviewed this article.


Nelson, Erik R. et al. "27-Hydroxycholesterol Links Hypercholesterolemia and Breast Cancer Pathophysiology." 29 November 2013. Science. https://www.sciencemag.org/content/342/6162/1094.abstract?sid=dc52e982-ca21-4cd7-b177-e1a825295a41

Gallagher, James. "Cholesterol 'fuels' breast cancer." 28 November 2013. BBC News.

"Breast Cancer Prevention-How to reduce your risk." Mayo Clinic.http://www.mayoclinic.com/health/breast-cancer-prevention/WO00091