Fatal Flaws in New Review of Omega-3 / Cancer Prevention Link
February 18 2006
|
3,085
views
The Journal of the American Medical Association (JAMA) recently released a "meta-analysis" of several dozen studies on omega-3 fatty acid intake. The authors came to the conclusion that dietary omega-3 fatty acids are unlikely to prevent cancer.
However, many experts on the subject of omega-3's and cancer, including Dr. William Lands and Dr. W. Elaine Hardman, agreed that the data from the studies was inadequate and unsuitable for the kind of analysis it was subjected to.
These problems, they argue, make it impossible to come to any meaningful conclusions from the data.
Problems in the studies included:
- They failed to determine or consider two key factors: omega-6 intake and overall dietary patterns over time
- They did not distinguish between intake of plant omega-3s versus marine omega-3s, or between lean and fatty fish, whose omega-3 content can vary by factors of 10 to 20.
- Participants' diets were relatively low in fish (e.g., one-half serving per week), and therefore also low in marine omega-3s, in many of the studies that showed no cancer-preventive benefit
- Cancers take years or decades to develop, but most of the population studies took only brief snapshots of participants' dietary habits