June 22, 2007 -- When it comes to reducing prostate cancer risk, some fatty acids may be more helpful than others, a new study shows.
The study focuses on omega-3 fatty acids and omega-6 fatty acids. The body needs both types of fatty acids and can only get them through foods or supplements.
But omega-3s and omega-6s should be in balance, and that balance is often out of whack in typical Western diets, note Wake Forest University's Yong Chen, PhD, and colleagues.
Western diets tend to be heavy on omega-6s and skimpy on omega-3s.
Omega-6s are found in meat and vegetable oils such as safflower oil, sunflower oil, corn oil, and soy oils. Sources of omega-3s include leafy green vegetables, walnuts, flaxseeds, and fatty fish such as salmon, herring, and sardines.
Chen's study, published in The Journal of Clinical Investigation, suggests that omega-3s may be beneficial against some prostate cancers -- at least, in the mice studied by Chen's team.
Some of the mice in Chen's study lacked a tumor-suppressing gene called Pten.
The mice ate chow laced with omega-3s and/or omega-6s daily for up to six months. Diets rich in omega-3s were linked to slower prostate cancer growth in the mice lacking the Pten gene.
The researchers also studied another group of mice for one year. Prostate cancer survival was best in mice eating lots of omega-3s and lacking the Pten gene.
Omega-6s were a different story. They appeared to hasten prostate cancer and worsen prostate cancer survival in mice lacking the Pten gene.
But the findings weren't quite as simple as "omega-3s good, omega-6s bad." Genes mattered, too.
In mice with normal Pten genes, omega-3s and omega-6s didn't seem to affect prostate cancer for better or worse.
The findings suggest that genes and diet interact to influence prostate cancer risk, according to the researchers.
Since the study only included mice, it's not clear if the results apply to people.
But observational studies have linked diets rich in omega-3s to lower cancer rates in people, note Chen and colleagues.
- Do you eat enough omega-3s? Talk with other men on our Men’s Health: Man-to-Man message board.