Breast cancer continues to be one of the most common cancers among women globally. As per the World Health Organization (WHO), breast cancer is the most diagnosed cancer among women across the globe, with more than 2.3 million new cases annually. Although many genetic, environmental, and lifestyle-related risk factors have been well researched, recent scientific studies are now leaning towards a potential dietary factor — specifically in regards to one of the most dangerous subtypes: triple-negative breast cancer (TNBC).
Recently published preclinical research by scientists at Weill Cornell Medicine, which appeared in the Science journal, reveals an unexpected connection between linoleic acid, a typical omega-6 fatty acid, and the growth acceleration of TNBC. This type of breast cancer is particularly hard to cure, as it does not contain the three major receptors — estrogen, progesterone, and HER2 — that are commonly targeted in standard hormone-based therapies.
Role of Linoleic Acid in Tumor Progression
Linoleic acid is one of the polyunsaturated fats that are in abundance in seed-based cooking oils like soybean, corn, sunflower, and safflower oils. It is also found in meat-based foods like pork and eggs. Although linoleic acid is an essential fatty acid that is needed for proper cellular functioning, its intake has skyrocketed over the last few decades with the global surge in ultra-processed and fried foods.
The Weill Cornell research team found that linoleic acid could play a role in tumor development in TNBC by activating a particular protein known as FABP5 (fatty acid-binding protein 5). The protein is heavily overexpressed in TNBC cells. Upon binding of linoleic acid to FABP5, it activates an mTORC1 signaling pathway, which controls cell growth and metabolism. In cancer, hyperactivation of the pathway results in fast tumor formation and growth.
Key Study Findings
With the use of animal models, the study established that mice with TNBC who were fed a diet high in linoleic acid had:
• Tumor growth and aggressiveness increased
• FABP5 expression elevated
• mTORC1 signaling pathway activity increased
Additional analysis of tumor and blood samples from newly diagnosed TNBC patients corroborated these findings, with higher levels of both FABP5 and linoleic acid compared to patients with other breast cancer subtypes.
Dr. John Blenis, senior author of the study and Professor of Cancer Research at Weill Cornell Medicine, said that these results shed light on the connection between dietary fat and cancer development. He highlighted the promise of creating personalized nutritional approaches based on a patient’s individual tumor biology and metabolic profile.
Implications for Global Public Health and Nutrition
While linoleic acid is an essential component of the human diet, this study gives cause for concern regarding the negative consequences of its overconsumption, particularly in areas where seed oil is a major part of the diet. Most Western diets, and those increasingly being followed in developing nations, have a disproportionately high omega-6 to omega-3 fatty acid ratio, which can lead to systemic inflammation and tumor growth.
In contrast to previous research that presented contradictory findings about dietary fat and cancer, this study is the first to define a clear biological pathway through which linoleic acid can stimulate cancer cell activity. Not only does it provide a foundation for future cancer research but also valuable insight for nutritional counseling and possible therapeutic targets, such as the FABP5-mTORC1 pathway.
Broader Impact and Future Directions
The significance of this finding extends beyond breast cancer. As noted by the study’s first author, Dr. Nikos Koundouros, this particular signaling pathway could be implicated in the onset of other cancers, and also in chronic diseases like obesity and type 2 diabetes, which are increasingly prevalent worldwide.
For researchers, public health organizations, nutritionists, and clinicians, this research places greater emphasis on the inclusion of dietary assessment within cancer prevention policy. At the individual level, it calls for awareness of more cautious eating habits, restraint in seed oil use, and increased knowledge of fatty acid balance within our diets.
While the international healthcare community heads toward a future of personalized medicine, nutrient recommendations based on a person’s specific risk factor profile could emerge as an integral component in cancer management and prevention of highly virulent cancers such as TNBC. This work is a cogent reminder that nutrition is a general health matter only — that it may even play a central role in creating and advancing disease-threatening conditions.
