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Omega-3 fatty acids may help prevent prostate cancer from growing

December 23, 2013

A new US study reports that men with prostate cancer who ate a low-fat diet and took fish oil supplements had lower blood levels of pro-inflammatory substances and a lower cancer cell cycle progression score (a measure used to predict cancer recurrence) than men who ate a typical Western diet.

The new research (1) investigated the potential biological mechanisms of a low-fat diet (only 15% of calories from fat) with fish oil supplements (5 g of omega-3 fatty acid–rich fish oil per day) for four to six weeks. In an earlier study, this diet had been shown to slow the growth of cancer cells in patients’ prostate cancer tissue compared to a traditional, high-fat Western diet (2). The new results showed that the low-fat fish oil diet lowered the cancer cell cycle progression score, known to be associated with the aggressiveness of the disease and patients’ risk of dying from cancer. In addition, patients following the diet had lower levels of pro-inflammatory substances (eicosanoids) compared to the ones with the Western diet. Moreover, partici- pants on the low-fat fish oil diet changed the composition of their cell membranes in both the healthy cells and the prostate cancer cells: the cell membranes had increased levels of omega-3 fatty acids from fish oil and decreased levels of omega-6 fatty acids.

The researchers concluded that a diet rich in inflammation-reducing omega-3 fatty acids and low in pro- inflammatory omega-6 fatty acids may provide protection against the growth and spread of cancer. While the Western diet – which consists of 40% of calories from fat with high levels of omega-6 fatty acids from corn oil and low levels of omega-3 fatty acids from fish oil – is what many Americans consume today, altering the diet may favorably affect the characteristics of prostate cancer. The researchers plan to determine the importance of these new findings for prostate cancer therapy in more detail in a randomized controlled trial. Prostate cancer is a leading cause of death among men in the United States. It is estimated that more than 230,000 American men will be diagnosed with prostate cancer in 2013, with more than 29,000 dying from their disease.

References

  1. Galet C. et al. 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. Published online November 2013.
  2. Aronson W. J. et al. Phase II prospective randomized trial of a low-fat diet with fish oil supplementation in men undergoing radical prostatectomy. Cancer Prev Res. 2011; 4(12):2062-2071.