The ketogenic diet, which is low in carbs and rich in fat, is very popular for losing weight, but a recent study on animals has shown that it may increase the risk of aggressive breast cancer.

The risk of triple-negative breast cancer can also be increased by excessive lipid levels brought on by fatty acids, a major aspect of obesity that encourages the formation of tumors, according to research from the University of Utah in the United States.

According to the study, which was carried out in preclinical mouse models, lipid-lowering treatments may be beneficial for obese breast cancer patients and survivors, and they should stay away from high-fat weight loss plans like ketogenic diets.

“The key here is that people have underestimated the importance of fats and lipids in the all-encompassing term that is obesity,” mentioned Keren Hilgendorf of the university’s Huntsman Cancer Institute.

“But our study shows that breast cancer cells are really addicted to lipids, and the abundance of lipids in patients with obesity is one of the reasons that breast cancer is more prevalent and more aggressive in these patients,” Hilgendorf said.

The group examined mice models fed a high-fat diet and employed models designed to have hyperlipidemia, or a high blood lipid content, but without other important indicators of obesity, such as elevated insulin and glucose levels.

The results, which were published in the journal Cancer and Metabolism, demonstrated that the high fat content was sufficient to hasten the formation of tumors. It’s interesting to note that reducing lipid levels was sufficient to limit the proliferation of breast cancer cells even while glucose and insulin levels were elevated.

Crucially, the study revealed that while a ketogenic diet can help cancer patients lose weight—a crucial goal—its high fat content “can have serious unintended side effects — even causing the tumor to grow.”

According to the study, lipids may also promote the growth of tumors in obese people with ovarian, colorectal, or various forms of breast cancer.