Thursday, April 28, 2011

Omega-3 Fatty Acid DHA Found To Increase Risk For Prostate Cancer

Omega-3 fatty acids are polyunsaturated fatty acids thought to have an anti-inflammatory effect. They may, but this study doesn't support it:

Serum Phospholipid Fatty Acids And Prostate Cancer Risk: Results From The Prostate Cancer Prevention Trial, American Journal of Epidemiology, April, 2011

Men with the highest levels of one type of omega-3 (docosahexaenoic acid (DHA), found abundantly in fish oil) were two and a half times more likely to have an aggressive form of prostate cancer than men with the lowest levels:
"Docosahexaenoic acid was positively associated with high-grade disease (quartile 4 vs. 1: odds ratio (OR) = 2.50)."
"The study findings are contrary to those expected from the antiinflammatory effects of these fatty acids and suggest a greater complexity of effects of these nutrients with regard to prostate cancer risk."
The curious thing ... polyunsaturated fats, including omega-3s, are easily oxidized, owing to their greater number of reactive double bonds. Once fats become oxidized in the body they can become pro-inflammatory.

Update, April 29: From the press release1 that accompanied the study:

Lead author Theodore Brasky, Ph.D, postdoctoral research fellow in the Hutchinson Center’s Cancer Prevention Program:
"We were stunned to see these results and we spent a lot of time making sure the analyses were correct. ... Our findings turn what we know — or rather what we think we know — about diet, inflammation and the development of prostate cancer on its head and shine a light on the complexity of studying the association between nutrition and the risk of various chronic diseases."
Another interesting bit:
"Among the study participants, very few took fish oil supplements – The majority got omega 3s from eating fish."

More discussion at: How Much Fish Oil Is Good?
1 A High Percentage Of Omega-3 Fatty Acids In The Blood Is Linked To An Increased Risk Of Aggressive Prostate Cancer, Fred Hutchinson Cancer Research Center, April 2011


Mike said...

Denise Minger is going to deconstruct this study shortly, which, I have no doubt, will shed a little more light into this area.

Bix said...

I hope so. I like seafood.

Laurie Endicott Thomas said...

When I looked Denise Minger up in Medline (enter the search string Minger D[AU] in the search field at, I found that she has published nothing whatsoever in the peer-reviewed scientific literature. In other words, none of her reviews have passed muster at any reputable scientific journal.

When I found her blog, I could tell instantly that she has no education in any scientific field related to nutrition or epidemiology. I've had college-level courses in statistics and research design, and I've been a medical technical editor for more than 20 years. I can spot a phony in a New York minute. Sure enough, when I read her bio, I found that she claims to have been an English major. She doesn't have even a bachelor's degree in nutrition or biostatistics or any other relevant discipline.

She claims that her knowledge of nutrition has come from self-education. The problem is that in self-education, you end up grading your own papers. It's a recipe for narcissism.

In short, I find it highly unlikely that she could shed light on this subject even if she tried. Why in the name of good common sense do people turn to uneducated people like her for guidance on a matter of life and death, instead of listening to eminent scientists like T. Colin Campbell?