In my now well practiced medical student voice, I replied "hmmm, I don't know, but I'll look into that."
For the past 10 days, the media has been screaming about the new finding of how fish oil causes prostate cancer. Time, Huffington Post, NY Times, CNN and other outlets have all chimed in on a recent study that describes a reported increased risk of prostate cancer from the consumption of marine based Omega 3 fatty acids. The data was significant and the publisher was the well renowned. What happened?
The study went like this. Back in 2004, researchers wanted to know whether vitamin E or Selenium (NOT Omega-3's) had any link to prostate cancer. So they took hundreds of aging men, did a baseline blood test for many different chemicals, proteins and vitamins, and told them to take either Vitamin E, Selenium, or neither. Seven years later, the researchers followed up and determined that Selenium did nothing and Vitamin E caused a slightly higher incidence of prostate cancer. They got a paper out of it, but decided to look back again at the baseline blood work to see if anything else seemed to be associated with the men getting prostate cancer. Who knows how many statistical analysis were run on how many proteins, metal and other microscopic elements flowing through blood were examined, but one showed statistical significance: Marine based Omega-3s.
"I have a prostate, and in the context of my mostly-plant diet, will continue to eat fish and take a daily omega-3 supplement" - Dave Katz MD, Director of Yale Prevention Research Center
This isn't science. This is statical wizardry. Science is generating a hypothesis based on prior evidence and testing it. This is fishing in a plethora of blood results to achieve statistical significance, knowing all along that a published finding will turn the eyes the media and every human with a prostate.
If researchers thought that Omega-3s were associated with prostate cancer in the first place, they would have had participants take fish oil or eat fish. But of course, they wouldn't because prior research has either found little to mixed evidence to say that omega-3 fish oils cause prostate cancer. And there's some studies that says it prevents prostate and breast cancer. However, they likely never got mentioned in mainstream media either because they agreed with our current notion that omega-3s are good for us, or because the finding that something doesn't cause cancer isn't alarming and therefore unworthy of major press.
"This is an observational study, and these studies usually generate rather than confirm hypotheses...It is a little puzzling, interesting, and provocative. It raises questions but is a long way from being definitive." - Eliot Brinton, MD, director of atherometabolic research at the Utah Foundation for Biomedical Research
This is why research is often a murky pond with a media that is quick to grow on it. An observational study that does no more than create a hypothesis is proclaimed as drastic finding. Researchers have no mechanism for omega 3s causing tumorigenesis and little context to say that it does. Until a prospective study targeting omega-3s and prostate cancer arises, we shouldn't be convinced. And hey, I hear salmon was just marked down at the supermarket.
buen dicho!
ReplyDelete-Lydi :)