Men with prostate cancer who ate a low-fat diet and took fish-oil supplements had lower levels of pro-inflammatory substances in their blood and a lower cell-cycle progression (CCP) score — a measure used to predict cancer recurrence — than men who ate a typical Western diet, UCLA researchers found. The findings are important because lower CCP scores are an indication of less aggressive prostate cancer, says UCLA Professor of Urology William Aronson, MD (RES ’93), chief of urologic oncology at the West Los Angeles Veterans Affairs Medical Center.
This study is a follow-up to a 2011 study by Dr. Aronson and his team that found that compared to a traditional, high-fat Western diet, a low-fat diet with fish-oil supplements eaten for four-to-six weeks prior to prostate removal slowed the growth of cancer cells in human prostate-cancer tissue. That short-term study also found that the men on the low-fat fish-oil diet were able to change the composition of their cell membranes in both the non-cancerous and the cancer cells in the prostate. They had increased levels of omega-3 fatty acids from fish oil and decreased levels of the more proinflammatory omega-6 fatty acids from corn oil in their cell membranes, which may directly affect the biology of the cells. “These studies are showing that in men with prostate cancer, you really are what you eat,” Dr. Aronson says. “The studies suggest that by altering the diet, we may favorably affect the biology of prostate cancer.”
For the current study, Dr. Aronson and his team wanted to look at the potential biological mechanisms at work in the low-fat fish-oil diet that may be providing protection against cancer growth and spread. They measured levels of proinflammatory substances in the blood and examined the prostate-cancer tissue to determine the CCP score. “This is of great interest, as the CCP score in prostate cancer is known to be associated with more aggressive disease and can help predict which patients will recur and potentially die from their cancer,” Dr. Aronson says. Further, Dr. Aronson and his team analyzed a pro-inflammatory substance called leukotriene B4 (LTB4) and found that men with lower blood levels of LTB4 after the diet also had lower CCP scores.
“Effect of a Low-Fat Fish Oil Diet on Pro- Inflammatory Eicosanoids and Cell-Cycle Progression Score in Men Undergoing Radical Prostatectomy,” Cancer Prevention Research, October 29, 2013