Low-fat fish oil diet changes cancer tissue in men with prostate cancer
Men with prostate cancer who ate a low-fat diet and took fish oil supplements had lower levels of proinflammatory substances in their blood and a lower cell cycle progression score, a measure used to predict cancer recurrence, than men who ate a typical Western diet.
The findings are important because lowering the cell cycle progression (CCP) score may help prevent prostate cancers from becoming more aggressive, said study lead author William Aronson, MD, a clinical professor of urology at the University of California at Los Angeles.
"We found that CCP scores were significantly lower in the prostate cancer in men who consumed the low-fat fish oil diet as compare to men who followed a higher fat Western diet," Aronson said. "We also found that men on the low-fat fish oil diet had reduced blood levels of proinflammatory substances that have been associated with cancer."
This study is a follow-up to a 2011 study by Aronson and his team that found a low-fat diet with fish oil supplements eaten for 4 to 6 weeks prior to prostate removal slowed the growth of cancer cells in human prostate cancer tissue compared to a traditional, high-fat Western diet.
"These studies are showing that, in men with prostate cancer, you really are what you eat," Aronson said. "The studies suggest that by altering the diet, we may favorably affect the biology of prostate cancer."
For this study, which was published in Cancer Prevention Research (2013; doi:10.1158/1940-6207.CAPR-13-0261), Aronson 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 the 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,” Aronson said. This can help predict which patients will have recurrent disease and potentially die from their cancer. Further, Aronson and his team analyzed one proinflammatory substance called leukotriene B4 (LTB4) and found that men with lower blood levels of LTB4 after the diet also had lower CCP scores.
"Given this finding, we went on to explore how the LTB4 might potentially affect prostate cancer cells and discovered a completely novel finding that one of the receptors for LTB4 is found on the surface of prostate cancer cells," Aronson said. He explained that further studies are planned to determine the importance of this novel receptor in prostate cancer progression.