Breast cancer survivors take heed: Ice cream, butter, cheese, high-fat milk, and other high-fat dairy foods could shorten your life.
That’s the conclusion of new research that found that people diagnosed with breast cancer who consume larger amounts of high-fat dairy products have higher mortality rates than peers who consumed more limited amounts of those foods.
“High-fat dairy intake was related to poorer breast cancer survival in long-term breast cancer survivors,” according to the study, which was published in the Journal of the National Cancer Institute. Candyce Kroenke, ScD, MPH, a staff scientist in the division of research at Kaiser Permanente and an alumna of the Robert Wood Johnson Foundation (RWJF) Health & Society Scholars program (2005-2007), was the lead author.
Consuming plant-based milks or non-fat dairy products could be “a reasonable approach” for limiting the risks of high-fat dairy products, particularly for those who have completed breast cancer treatment, Kroenke and her co-authors write. Consuming lower-fat dairy products, such as skim milk, may also be advisable and is consistent with general nutrition guidelines, they add.
In an interview, Kroenke hypothesized that modern milk-producing practices may play a part in the relationship between high-fat dairy intake and breast cancer prognosis.
In Western countries, she said, current practices enable milk producers to milk pregnant cows to increase production and profitability. Milk from pregnant cows contains higher levels of estrogen, which promotes cancer cell growth. Estrogen levels are higher in high-fat than in low-fat dairy products because estrogens tend to reside in fat.
“High-fat dairy consumption may increase levels of estrogens, which may augment the risk of breast cancer recurrence and mortality,” Kroenke and her colleagues write.
Other studies have explored the link between dairy intake and health outcomes, but Kroenke’s is the first to break out the effects of high- and low-fat dairy intake on breast cancer mortality risk. It generated hundreds of stories in the news media, a clear sign that it “struck a chord” in the medical community and in the population at large, Kroenke said.