News - Low-fat diet plus fish may slow prostate cancer growth
According to a study by researchers at UCLA's Jonsson Comprehensive Cancer Centre, men who ate a low-fat diet with fish oil supplements for four to six weeks before having their prostate removed had slower cancer-cell growth in their prostate tissue than men who ate a traditional, high-fat Western diet.
Patients undergoing radical prostatectomy were randomly assigned to receive a low-fat diet with 5g of fish oil daily or a control Western-style diet for four to six weeks prior to surgery. To ensure the participants stuck to their new diets, the meals were prepared by chefs and delivered in bulk to study participants several times a week. Participants also met with a dietician, kept food diaries and were required to return uneaten food.
Blood samples were taken before and after the dietary period so the scientists could assess the patients’ levels of growth factors, omega fats and inflammatory messengers, as well as monitor markers of cancer growth. The removed prostate tissue was also studied for difference in growth.
When the results were analysed, the researchers found that those in the low-fat diet plus fish oil group had decreased prostate cancer proliferation. This was accompanied by a change in the composition of prostate cell membranes in the men on the low-fat, fish-oil-supplement diet. The membranes had heightened levels of omega 3 fatty acids and decreased levels of omega 6 fatty acids.
In the second lab-based arm of the study, the scientist also found that blood obtained from patients after the low-fat, fish oil diet slowed the growth of prostate cancer cells in a test tube, while blood from men on the Western diet did not slow cancer growth.
"The findings that the low-fat, fish oil diet reduced the number of rapidly dividing cells in the prostate cancer tissue is important because the rate at which the cells are dividing can be predictive of future cancer progression," the lead scientist said. "The lower the rate of proliferation, the lesser the chances that the cancer will spread outside the prostate, where it is much harder to treat."
The scientists are now planning a larger study over a longer duration to confirm these findings.
Aronson WJ et al. Phase II Prospective Randomized Trial of a Low-Fat Diet with Fish Oil Supplementation in Men Undergoing Radical Prostatectomy. Cancer Prev Res (Phila). 2011 Oct 25.