UCLA Health Jonsson Comprehensive Cancer Centre found that a diet low in omega-6 fatty acids and high in omega-3 fatty acids, along with fish oil supplements, can significantly lower prostate cancer cell proliferation in men under active surveillance. The Journal of Clinical Oncology published the study, which explores the potential significance of dietary interventions in treating early-stage prostate cancer.

"This is an important step toward understanding how diet can potentially influence prostate cancer outcomes," said Dr. William Aronson, Professor of Urology at UCLA's David Geffen School of Medicine and the study's lead author. 

For men with low-risk prostate cancer, active surveillance is a popular technique that involves regular observation of the disease without immediate treatment. However, by five years, approximately half of the patients on active surveillance will require more severe treatments such as surgery or radiation. 

Researchers undertook the CAPFISH-3 experiment in the hopes of finding non-invasive techniques to delay illness progression. The study comprised 100 men with low- or favorable intermediate-risk prostate cancer.  Participants were randomly randomised to either continue eating their usual diet or follow a diet low in omega-6 and high in omega-3, supplemented with fish oil capsules, for one year. 

The intervention group received personalized counseling from licensed dietitian nutritionists, who advised them to reduce omega-6-rich foods, such as fried snacks and processed meals, while increasing omega-3 consumption through dietary changes and supplements. 

The study looked at changes in the Ki-67 index, which is a biomarker that monitors cancer cell proliferation and predicts cancer development and survival. Men in the intervention group had a 15% decrease in the Ki-67 index, compared to a 24% increase in the control group. 

"This significant difference suggests that dietary changes may help slow cancer growth, potentially delaying or even preventing the need for more aggressive treatments," said Dr. Aronson, who also serves as Chief of Urologic Oncology at the West Los Angeles Veterans Affairs Medical Centre. 

Despite the positive results, the study found no changes in other cancer markers, such as Gleason grade, which is widely used to detect disease progression. 

The findings provide hope to men seeking lifestyle modifications to treat prostate cancer. "Many men are interested in lifestyle changes, including diet, to help manage their cancer and prevent the progression of their disease," Aronson told me. According to our findings, a simple diet adjustment could potentially slow cancer growth and delay the need for more aggressive interventions.

The experiment also emphasized the patients' ability to control their eating habits.  Counsellors advised participants on practical replacements, such as using olive oil or vinegar-based dressings rather than high-fat options like mayonnaise. 

Experts emphasize that more research is necessary to confirm the long-term benefits of dietary changes on cancer progression, despite the promising findings. They propose larger studies to investigate how omega-3 fatty acids and reduced omega-6 intake affect survival rates and the requirement for treatment. 

"This study supports the need for additional research into how lifestyle modifications, such as diet, can complement medical approaches to cancer management," stated Dr. Susanne Henning, the study's senior author and former director of the nutritional biomarker laboratory at UCLA's Centre for Human Nutrition. 

The findings serve as a solid foundation for ongoing discussion about the importance of nutrition in cancer care, as well as practical insights for men undertaking active monitoring.