New research conducted at Weill Cornell Medicine found that linoleic acid, a fat found in seed, vegetable and nut oils can affect breast cancer cells, causing them to multiply.

Using linoleic acid regularly could increase the risk of triple-negative breast cancer in women, says the New York Post. This is the most aggressive form of cancer that spreads faster and needs a highly individualized treatment plan that includes chemotherapy, surgery and sometimes radiation therapy. The survival rate is lower, around 77%, compared to 90% for other types of breast cancer.

“We now know that linoleic acid feeds cancer cell growth in a very specific way,” said Dr. John Blenis, the study’s senior author and a cancer researcher at Weill Cornell. But Blenis added that people should not avoid oils that contain linoleic acid altogether but use them in moderation along with other oils.

Linoleic acid is an essential polyunsaturated omega-6 fatty acid found in various vegetable oils, seeds, and nuts. It is a crucial component in our diet but has been linked to certain health concerns, including the potential to affect breast cancer cells negatively. Sunflower oil is one of the richest sources of linoleic acid, often containing up to 68% of this fatty acid. It is commonly used in cooking, salad dressings, and as a key ingredient in many processed foods. Other seed oils include safflower oil, corn oil, soybean oil, and sesame oil.

While omega-6 fatty acids are considered to be essential for many body processes, the abundance of this fat in our typical Western diet has risen significantly since 1950 with the increased use of seed oils in fried and ultraprocessed foods, according to a news release by Weill Cornell Medicine. This has led to concern that excessive omega-6 intake might be one of the factors driving the rising rates of certain diseases, including breast cancers. 

But experts say that other studies show that seeds oil don’t promote breast cancer, and that we need to include other factors such as genetics, overall diet and environmental exposures in assessing risk factors. Linoleic acid’s role in triple-negative breast cancer is just one piece of the puzzle, according to The Conversation. A diverse diet rich in fruits, vegetables, whole grains, nuts and low-fat dairy products instead of one based on processed foods is a good way to promote healthy aging and prevent disease.