Women who have had breast cancer might want to walk away from the brie, the butter and the ice cream.

According to a study of 1,893 women, breast cancer survivors who average as little as one serving per day of high-fat dairy foods have a 49 percent higher risk of dying from breast cancer than those who eat little or no high-fat dairy.

In absolute terms, breast cancer survivors who consumed the most high-fat dairy had about a 12 percent risk of dying of the disease.

The elevated mortality risk is therefore “modest,” said the study’s lead author, Candyce Kroenke, a staff scientist at Kaiser Permanente, the nonprofit health-care provider. “But since it may not be so difficult to lower your consumption of high-fat dairy, I think if you have breast cancer, it’s worthwhile.”

The research, published in the Journal of the National Cancer Institute, is notable because other studies have examined whether consuming milk, cheese, ice cream and other dairy products is related to breast cancer. The results have been a confusing muddle: Some found that women who eat a lot of dairy have a higher risk of breast cancer, others found they have a lower risk and still others found no difference.

The Kaiser study is the first to separate out the effects of high- and low-fat dairy on women with breast cancer.

“This is a very well-done study by highly regarded researchers,” said Michelle Holmes, an associate professor of medicine and epidemiology at Harvard Medical School and Harvard School of Public Health, who was not involved in the research. It advances scientists’ understanding of how diet affects breast cancer, she said, and presents women with a simple dietary choice: “It’s for each woman to decide, but if you don’t eat high-fat dairy, you can get the same nutrients from other sources,” including low-fat versions.