A follow-up study reveals that men suffering from prostate cancer who took fish oil supplements alongside a low-fat diet demonstrated changes in their cancer tissue that may indicate reduced cancer aggression.

This is according to research published in the journal Cancer Prevention Research.

Prostate cancer is the most common cancer among American men. According to the American Cancer Society, around 238,590 new cases of the cancer will be diagnosed in the US this year, highlighting the need for new interventions that may reduce prevalence and progression of the disease.

Now, researchers from the University of California-Los Angeles (UCLA) have looked to changes in diet as a potential intervention.

This most recent study follows on from previous research conducted by the team in 2011.

The previous study required two groups of men with prostate cancer to follow two separate diets for a period of 4 to 6 weeks.

The first group followed a low-fat diet consisting of 15% of calories from fat, and they also took 5 g of fish oil a day through five fish oil supplements in order to have a regular intake of omega-3 fatty acids.

Omega-3 fatty acids are types of fat that are commonly found in plant and marine life oils. Omega-3 is known to reduce inflammation and has been linked to many health benefits, including the prevention of oral and skin cancers.

The second group followed a high-fat Western diet. This diet consists of around 40% of calories from fat – the equivalent to what many Americans consume each day, the researchers say.

The Western diet also includes high levels of omega-6 fatty acids from corn oil but low levels of fish oil that provides omega-3.

The men who adopted the low-fat diet showed slowed growth of cancer cells, compared with the men who followed the high-fat diet.

Furthermore, the research found that men following the low-fat diet showed changes in the composition of their cell membranes in both healthy cells and cancer cells in the prostate.

These men showed increased levels of omega-3 fatty acids as a result of the fish oil supplements but showed reduced levels of omega-6 fatty acids in the cell membranes, which could directly affect the cell’s biology, the researchers say.

For this most recent study, the investigators wanted to determine exactly how the low-fat fish oil diet works to produce the effects found in their previous research.

Therefore, they measured the levels of pro-inflammatory substances in the blood and analyzed the men’s prostate cancer tissue in order to find out their cell cycle progression (CCP) scores – a measure of aggression within prostate cancer cells used to determine a patient’s likelihood of recurrence.

On analyzing one particular pro-inflammatory substance called leukotriene B4 (LTB4), it was found that men with lower levels of this substance after following the low-fat diet also had lower CCP scores.

Further analysis revealed that one of the receptors of LTB4 is present on the surface of prostate cancer cells, which the researchers say is a “completely novel finding.”

The investigators note that their findings are significantly important, as being able to lower a patient’s CCP scores could be a way of preventing prostate cancers from becoming more aggressive.

Commenting on their findings, William Aronson, a clinical professor of urology at UCLA and lead study author, says:

These studies are showing that, in men with prostate cancer, you really are what you eat. The studies suggest that by altering the diet, we may favorably affect the biology of prostate cancer.”

The research team notes that further studies are planned at UCLA next year to investigate the importance of the LTB4 receptor in prostate cancer progression.

Medical News Today recently reported on a study suggesting that zebrafish may predict the therapy response to prostate cancer.