Is Farm-Raised Tilapia Really Bad News?
News reports all over the internet have heralded a recent study published in the Journal of the American Dietetic Association showing that farm-raised tilapia is very rich in the supposedly inflammatory "bad fat" we know as arachidonic acid or, for short, AA.
For example, NewsWise.Com carried a story entitled "Researchers Say Popular Fish Contains Potentially Dangerous Fatty Acid Combination" that reported the following:
They say their research revealed that farm-raised tilapia, as well as farmed catfish, "have several fatty acid characteristics that would generally be considered by the scientific community as detrimental." Tilapia has higher levels of potentially detrimental long-chain omega-6 fatty acids than 80-percent-lean hamburger, doughnuts and even pork bacon, the article says.
Doughnuts and hamburgers -- really? I would never have thought to lump the two foods together, since one is a junk food made from refined flour and fried in hydrogenated vegetable oil and the other is a health food packed with all kinds of vitamins and minerals and healthy fats, but somehow the authors of this study managed to do so.
In the original report, the authors stated that a serving of pork bacon contains 191 mg of AA, a serving of ground beef contains 34 mg, and a doughnut contains 4 mg, referencing the latest release of the USDA nutrient database. Nevermind the fact that ground beef contains eight times more AA than their theoretical doughnut, revealing the latter to be a negligible source of this fatty acid, but this must have been one imaginative doughnut because the even the cream filling doughnuts listed in the USDA database seem to have only 1 mg of AA.
But let's move on to the crux of the matter.
I'm no advocate of fish farming, but my first reaction to this article was that maybe I should start eating tilapia. Those of you who have read my PUFA Report know I have a fairly high opinion of AA.
The current study did not take any measurements from wild tilapia, but found that farm-raised tilapia was relatively low in total fat, had a high proportion of saturated and monounsaturated fatty acids, and was unusually rich in AA and low in the omega-3 fatty acid EPA, yielding a very high ratio of AA to EPA, a supposed index of inflammatory potential. Farm-raised salmon and other species, by contrast, were much higher in total PUFA and EPA. Unfortunately, they did not measure DHA.
This, they say, is very bad. AA is a substrate for inflammatory compounds, which make it a contributor to heart disease and all kinds of other illnesses.
The news article points out in a single sentence that the editorial accompanying the report mentions the "controversy" about AA, but never quotes it. Let me quote it here:
Nevertheless, in this reviewer's opinion, evidence from relevant human studies that a higher consumption of arachidonic acid promotes atherosclerosis and coronary heart disease is quite weak, and the assertion that because a serving of tilapia contains more arachidonic acid than hamburger or bacon it has greater "inflammatory potential," is based on a potentially flawed conception of the physiological impact of dietary arachidonic acid.
Not only that, but, as I describe in my first PUFA Report, a deficiency of AA leads to low levels of sex hormones, hair loss, scaly skin, infertility, and, if the deficiency is moderate enough to allow ovulation and thus pregnancy, extended labor that is torturous and possibly fatal.
So, while it's true that many humans suffer from inflammatory diseases, it's also quite true that many humans suffer from hair loss, skin problems, infertility, and difficult labor. Could these, in some cases, be tied to a deficiency of arachidonic acid? The research from Harvard showing that the intake of milkfat is associated with increased fertility certainly suggests that this is the case.
And what of the high ratio of AA to EPA in farmed tilapia? I'm not concerned. As I pointed out in a recent newsletter, researchers at the University of Connecticut last year showed that low-carb dieters eating unlimited amounts of AA-rich foods like heavy cream had far better reductions in inflammatory markers than low-fat dieters. What's more, the reduction in inflammation was directly correlated to the AA-to-EPA ratio in the bloodstream!
As described in my PUFA Report, I suspect that EPA does not even belong in the mammalian body. Rather, the two fatty acids we want are AA and DHA. EPA is mostly present when the human body cannot keep up with processing the EPA from fish oils and the alpha-linolenic acid from plant oils into the DHA it needs. The UConn study found that the low-carb diet led to higher DHA levels and lower EPA levels, suggesting better conversion of the fatty acids on the diet.
I am not ready to advocate farmed tilapia. I would want to see the levels of other nutrients and how they compare to wild tialpia.
That said, if you suffer from hair loss or infertility or want to boost your testosterone or prepare for a pregnancy, while liver and egg yolks would be the best way to stock up on AA, we now know that a serving of tilapia here and there might help give you a boost as well.