Low fat, fish oil supplemented diet might slow prostate cancer
Preliminary study shows diet could impact spread of prostate cancer
Scientists have been studying the effects of diet on prostate cancer outcomes. Researchers at UCLA’s Jonsson Comprehensive Cancer Center have shown eating a low fat diet, supplemented with fish oil can slow the growth of prostate cancer cells.
In their study, the researchers compared the low fat, fish oil diet to a typical Western diet.
The research showed men can change the composition of both healthy and prostate cancer cell membranes by following a low fat diet and taking fish oil supplements. The changes occurred in just a matter of weeks. Men in the study were scheduled for radical prostatectomy. Forty-eight men completed the trial.
Dr. William Aronson, the study’s first author, said more research is needed to understand how higher levels of omega-3 fatty acids in fish oil and lower levels of omega 6 levels affect the biology of the cell structure.
When the investigators looked at prostate cancer cells in a test tube they found the cancer cells were growing more slowly from men on the low-fat; fish oil diet, compared to those on a typical Western diet. The study is published in Cancer Prevention Research.
Dr. William Aronson, the study’s first author and a researcher explained:
“The finding 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 lower the rate of proliferation, the lesser the chances that the cancer will spread outside the prostate, where it is much harder to treat.”
Blood samples were taken before and after the men started the diet. The researchers also examined tissue removed from the prostate.
Aronson and his team found the same results in previous studies done on animals. He says the study suggests men who alter their diet can change the course of prostate cancer.
One of the findings is that a low-fat, fish oil diet was associated with lower levels of a protein called Ki-67, which is linked to more aggressive prostate cancer.
Aronson notes the food restrictions for the study were well-controlled – something that can be a problem when studying the impact of diet on health.
The key to this study was having the meals prepared and delivered to the study participants,” Aronson said. “This resulted in a very high rate of compliance, making the study very well controlled.”
The Western diet consisted of high levels of omega-6 fatty acids, which is typical of what most Americans consume. Forty percent of the calories came from fat. The low-fat arm of the study allowed 15 percent of calories from fat and was combined with 5 grams of fish oil.
Omega 6 fatty acids, also known polyunsaturated fatty acids (PUFAs), come from food consumption such as corn oil, processed meats, nuts, soy, sandwich spreads and mayonnaise.
A healthy ratio of omega 6 to omega 3 fatty acids, which come from from whole grains, fresh fruits and vegetables, fish, olive oil, garlic, and an occasional glass of wine, should be 1:1.
A Western diet is typically 16 to 17 times higher in omega 6 fatty acids, which may be cancer promoting from inflammation.
The researchers are planning a larger study. The scientists they can’t yet recommend switching to a low-fat diet with fish oil slow prostate cancer. The next investigation will follow men for one year to confirm the finding that a low-fat, fish oil supplemented diet might slow prostate cancer growth.