Polyunsaturated fatty acids in the prevention, treatment, and survival of breast cancer.

Breast cancer is one of the leading causes of death among women worldwide, and its occurrence is shaped by both nonmodifiable factors (such as age and genetics) and modifiable factors, among which diet plays a central role. This review addresses the role of polyunsaturated fatty acids (PUFAs) in the prevention, development, and treatment of breast cancer, highlighting their capacity to modulate inflammatory processes and impact mammographic density. Evidence indicates a negative association between n-3 PUFAs intake and breast cancer risk, whereas the role of n-6 PUFAs in disease development remains poorly elucidated. N-3 PUFAs supplementation has been shown to improve patient's quality of life by alleviating treatment-related side effects, such as aromatase inhibitors-induced musculoskeletal pain, and by reducing systemic inflammation. However, responses vary among individuals, emphasizing the need to personalize dietary strategies by considering factors such as body mass index and nutritional status. Although current evidence reinforces the importance of incorporating n-3 PUFAs and regulating n-6 PUFAs intake, further research is needed to optimize dosage and supplementation duration and to assess their long-term impact on breast cancer prevention and treatment.