Atlantic Nutraceuticals and Industry Comment on Omega-3s and Prostate Cancer Study April 29 2014
It is clear that negative scientific studies have much more media value than positive ones. After all, what would be sensational enough for a newspaper to get new readers about yet another study demonstrating a heart health benefit? However, what if omega-3s were linked to an increased risk of prostate cancer? That would be sexy enough to grab headlines! And of course, that is exactly what happened yesterday, with nearly every major media outlet in the world reporting on a study that correlated higher blood levels of long chain omega-3s to an increase in prostate cancer risk and also to a higher incidence of the most aggressive form.
Let's think about that for one second. If this were true and these statistics were accurate, then the countries with the highest omega-3 intakes would have the highest incidences of prostate cancer. Unfortunately, the researchers—and the media—failed the "common sense" test. Countries such as Japan and Iceland have the highest omega-3 intake levels—multiples higher than the typical American and Western European diets—and yet, nearly all of the countries with the highest incidences of prostate cancer are eating low omega-3 Western diets.
Another interesting issue with the study is that the difference in the mean plasma levels of omega-3s between the patients who developed prostate cancer and those that did not was only 0.2 percent. That is awfully sensitive. Consider that the typical difference in plasma levels between Americans and Japanese is 4 percent. If the study found that 0.2 percent higher mean omega-3 plasma levels equated to 23 percent higher risk of prostate cancer, then that means the Japanese should have 20 times higher risk, or a 460 percent higher incidence than the United States. Actually the exact opposite is true; the incidence rate in the United States is more than five times higher than in Japan.
The lead researcher, a cancer expert, also went on MSNBC and said he did not think there were any cardiovascular benefits to omega-3 supplements, so no men over the age of 50 should be taking fish oil. Let's ignore the fact that he is not a cardiovascular disease expert and was using another misreported, sensationalist story as the basis of his claim. His study actually had nothing to do with supplements, yet he recommended people stop taking them!
The researchers measured the plasma levels of omega-3s in the patients. Plasma is an excellent marker of recent omega-3 intakes, but it does not tell you whether the omega-3s came from seafood, supplements or some other source. The researcher has not recommended that males older than 50 should stop eating seafood, though, and that contributes more to omega-3 intakes in the world than supplements. It does beg the question of what would cause him to make unsupported statements. Is there a research bias against supplements here?
There are also other issues with the study that lipid scientists would have recognized. For one, cancers are diseases that take long periods of time to manifest themselves, so plasma omega-3 levels may not be a good marker of omega-3 intakes as it relates to a long-term disease because it can be washed out of plasma in as little as 48 hours. If the media would have interviewed a fatty acid scientist, they likely would have pointed this out pretty quickly.
To put this a little more succinctly, it would be nice if the media would do their job and interview people that can put things that seem too good (or bad) to be true in a little more context. It would also be nice for fatty acid experts to be involved in studies using fatty acids. The research produced from such collaborations would be much stronger.