The study, published in Cancer Prevention Research, reports that consumption of 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 score (a measure used to predict cancer recurrence) than men who ate a typical Western diet, UCLA researchers found.
Led by Professor William Aronson of UCLA, the team said that their findings are important because lowering cell cycle progression (CCP) score may help prevent prostate cancers from becoming more aggressive
"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 pro-inflammatory substances that have been associated with cancer."
The new findings come as a follow-up to a 2011 study also conducted by Aronson, that suggested 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 compared to a traditional, high-fat Western diet.
The new findings – which come from post-hoc analysis of the 2011 trial data - also revealed that men on the low-fat fish oil diet were able to change the composition of their cell membranes in both the healthy cells and the cancer cells in the prostate – with an increased level of omega-3 fatty acids from fish oil and decreased levels of more pro-inflammatory omega-6 fatty acids in the cell membranes.
This alteration in cell membrane composition may directly affect the biology of the cells, Aronson said.
"These studies are showing that, in men with prostate cancer, you really are what you eat," he commented.
"The studies suggest that by altering the diet, we may favourably affect the biology of prostate cancer."
Further, Aronson and his team analysed one 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.
"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.
Further studies are planned to determine the importance of this novel receptor in prostate cancer progression, he said.
Based on the results of his research, Aronson has already been granted funding to commence a prospective, randomised trial at UCLA next year.
The research will study 100 men who have elected to join the active surveillance program, which monitors slow-growing prostate cancer using imaging and biopsy instead of treating the disease.
Participants will be randomised into a group that eats their usual diet or to a low-fat fish oil diet group.
Aronson will measure markers from prostate biopsy tissue to check for cell growth and CCP score.
Source: Cancer Prevention Research
Published online ahead of print, doi: 10.1158/1940-6207.CAPR-13-0261
“Effect of a Low-fat Fish Oil Diet on Pro-inflammatory Eicosanoids and Cell Cycle Progression Score in Men Undergoing Radical Prostatectomy”
Authors: Colette Galet, Kiran Gollapudi, et al