Are tilapia inflammatory?

Image: Michael Rupert HayesSo, you started eating Paleo? You’re browsing the blogs trying to figure out just what the Paleo diet is. But one thing you know for sure, fish is Paleo. Indeed, 70 to 80 thousand years ago our ancestors living  in Blombos Cave, South Africa were catching fish in the Indian Ocean. They also created the first clear symbolic image, a block of ochre engraved with cross-hatched lines bordered above and below by parallel lines. This stunning find suggests the importance of fish to the development of the human mind. After all, seafood has plenty of omega-3 fatty acids, right?  

At the fish counter of your grocery store you pick up a couple of tilapia. The fish are small, bland, and can easily be incorporated into a variety of meals. They are just the right size to serve as the main course. Only one problem - well, probably more than one - tilapia have minimal, if any, omega-3 fatty acids (n-fatty acids) and are high in omega-6 fatty acids: a recipe for inflammation. (We need both omega-3 and omega-6 fatty acids; what is important is the ratio of the two.) As a primarily vegetarian fish, tilapia, even wild-caught as in the image above, are very low in omega-3. Unfortunately, in the farm-raised tilapia at you store, it is even lower.

As fast growing fish and with little mercury, tilapia are increasingly important in aquaculture. Most are farm-raised in Asia and Latin America, with China the major producer. Bruce Einhorn, in the recent Businessweek article “From China, The Future of Fish”, raised concern about Chinese-raised tilapia:

Despite environmental warnings about Chinese-raised tilapia from watchdog groups such as the Monterey Bay Aquarium's Seafood Watch, which publishes an influential best choices/avoid list of seafood and rates Chinese-raised tilapia as "avoid," U.S. consumption keeps rising.

How do Chinese officials respond to this recommendation? Einhorn notes:

Chinese aquaculture officials object strongly to Seafood Watch's "avoid" recommendation. "They don't believe in aquaculture," Sporns says. "The Monterey Bay Aquarium makes money off of ocean fish." Tilapia, a small and visually nondescript omnivore, is not a fish that captures the imagination of aquarium goers. "How many tilapia do you see there?" asks Sporns. "None."

If you want to learn more about tilapia farming and sales, I highly recommend Einhorn’s article. But, what does the research show?

In their 2008 study, KL Weaver and colleagues at Wake Forest University School of Medicine evaluated the concentrations of polyunsaturated fatty acids (PUFA) in commonly eaten fish.

The four most commonly farmed fish, Atlantic salmon, trout, tilapia, and catfish, were more closely examined. This analysis revealed that trout and Atlantic salmon contained relatively high concentrations of n-3 PUFA, low n-6:n-3 ratios, and favorable saturated fatty acid plus monounsaturated fatty acid to PUFA ratios. In contrast, tilapia (the fastest growing and most widely farmed fish) and catfish have much lower concentrations of n-3 PUFA, very high ratios of long chain n-6 to long chain n-3 PUFAs, and high saturated fatty acid plus monounsaturated fatty acid to PUFA ratios. Taken together, these data reveal that marked changes in the fishing industry during the past decade have produced widely eaten fish that have fatty acid characteristics that are generally accepted to be inflammatory by the health care community.” (emphasis added)

The following year, K Young suggested in a literature review that:

… tilapia have an elevated amount of omega-6 FAs (n-6) and a deficient amount of omega-3 FAs (n-3), a possibly unhealthy proportion for humans. A high n-6:n-3 ratio is problematic because too much arachidonic acid, an n-6 FA, promotes inflammation, which aggravates heart disease and other illnesses.

On the other hand, tilapia have some favorable properties as succinctly noted in Wikipedia: “Tilapia is a low saturated fat, low calorie, low carbohydrate and low sodium protein source. It is a source of phosphorous, niacin, selenium, vitamin B12 and potassium."

The ratio of omega-6 to omega-3 in tilapia is about 11:1. The ratio in the standard American diet (SAD), with its high quantity of processed and refined foods, is even higher at about 16:1. What about the Paleo diet? Nutritionist Jonny Bowden writes:

Now, if you go back and look at the diet of all the hunter-gatherer societies, the “natural” diet of Paleolithic man, and the basic diet of any civilization that lived off the land, eating unprocessed and unrefined foods, you find an interesting relationship between the consumption of these two type of fatty acids: It was always in balance. Most researchers agree that the ideal relationship of omega-6 (pro-inflammatory fatty acids) to omega-3 (anti-inflammatory fatty acids) fats is about 1:1, which is exactly the ratio you find in the diet of the hunter gatherer societies that were so remarkably free of the diseases of aging.

So, buy those tilapia or not? Not me, at least not now. There are many other fish with favorable properties. Unfortunately making the right seafood choices is complex. This link may help.

Despite these concerns, aquaculturists are increasingly turning to tilapia farming to meet increasing worldwide demand. Maybe the future of farmed-fish such as tilapia will be supplementation to improve their fatty acid ratio. If you are picking up tilapia at the grocery store, find out where they came from, and, if possible, what they were was fed. The more you know…

Comments

[Bryan D.]

A quick post for those switching to a paleo diet. It's still important to make sure that all those fruits and vegetables are safe to eat in large quantities. If you aren't quite to buying organic everything, take a look at this article pick wisely. Happy eating! BD

http://www.care2.com/greenliving/top-12-toxic-fruits-and-vegetables-2.html