Researchers investigating the role of fatty acids in the aggressiveness of early stage prostate cancer have found that higher concentrations of polyunsaturated fat, such as omega-3 and omega-6 fatty acids, were linked to less aggressive tumour growth.
“Research has shown that populations with a low-fat diet have lower rates of prostate cancer, although studies about the types of dietary fat have had mixed results,” said Mohsen Meydani of the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University. “Our study, which relied on tissue samples rather than patient recall of dietary fat intake, found that there is a probable link between polyunsaturated fat intake and a slower growth of cancer.”
The study measured the level of fats in prostate tissue from men with localized prostate cancer. Tissue specimens were collected from 196 men and analyzed for their concentration of fats. The study found that those men with less advanced prostate tumours had higher concentrations of overall polyunsaturated fatty acids, and particularly high concentrations of omega-3 fatty acids, than men with more advanced tumours. The study also found that those men with more advanced tumours had a lower ratio of omega-3 fatty acids to omega-6 fatty acids.
Both omega-3 and omega-6 fats are not made in the human body and must be obtained through food. The typical North American diet is too high in omega-6 and too low in omega-3 fat. Some of the best food sources of omega-3 fatty acids are fish, particularly fatty fish such as sardines and salmon, as well as soybeans, canola, walnut and flaxseed, and their oils.
Friedman Nutrition Notes, Mar/Apr 2005