Tuesday, June 11, 2013

Are all fish equally healthy?

I would like to preface today's blog by stating that it would take a book to do real justice to this subject.

A few months ago, I wrote a hearty defense of fish as part of a healthy diet.(see http://mdprevent.blogspot.com/2013/03/in-defense-of-fish-consumption.html). Since that time, meaningful studies continue to emerge supporting the value of including fish.  A recent study showed that pesco-vegetarians (vegetarians who also consume fish) do better than any other category of eater, including pure vegans, when it comes to overall mortality. The study, however, did not distinguish among types of fish.

In my practice, I counsel many patients about the importance of consuming fish. Many patients say they already do. On closer scrutiny, it turns out that most are eating tilapia, farm-raised salmon, and canned tuna fish.  When I recommend fish, these are not my first choices. As a choice, they are undoubtedly preferable over hamburgers, hot dogs, and cured meats. They are also superior to other forms of red meat and caged fowl. But when it comes to choosing among fish, they rank low.

My first choice and champion remains wild Alaskan Salmon. One of the great things about wild Alaskan Salmon is that the salmon is often caught after it spawns and closer to the end of it's life cycle. This allows for sustainability of the species and is ecologically friendly.

I make a point about Alaskan salmon because wild Alaskan salmon as opposed to its Oregon and California counterparts, has far less Polychlorinated biphenyl (PCBs) contaminants. In fact, last year, Oregon issued a safety alert about wild Oregon Salmon being highly contaminated. So please take note when selecting wild Salmon, it's source is equally important to it being wild.

Tilapia and other farm raised fish, including salmon, contain far less of the essential Vitamin D and health promoting omega-3s than does wild Alaskan Salmon. In fact, wild Alaskan salmon has four times the Vitamin D as it's farm raised equivalent. Wild salmon tends to be leaner, having less saturated fats, and is an excellent and essential source of Vitamin B12 and protein. It alo contains an generally considered healthy anti-oxidant called astaxanthin. Free of articial dyes, food additives, antibiotics and growth hormones, Wild Alaskan salmon is my ultimate food.

What about other fish?

I like wild sardines and herring. As small, non-predatory fish, they also contain few contaminants and are high in omega-3 fatty acids. Costco and many supermarkets sell wild sardines in a can and wild herring in wine sauce.

What about tilapia, a perennial favorite?

Here's a snippet from Wikipedia discussing the problem with tilapia.

"Typical farm-raised tilapia (the least expensive and most popular source) have low levels of omega-3 fatty acids (the essential nutrient that is an important reason that dieticians recommend eating fish), and a relatively high proportion of omega-6. "Ratios of long-chain omega-6 to long-chain omega-3, AA to EPA, respectively, in tilapia averaged about 11:1, compared to much less than 1:1 (indicating more EPA than AA) in both salmon and trout," reported a study published in July 2008. The report suggests the nutritional value of farm-raised tilapia may be compromised by the amount of corn included in the feed. The corn contains short-chain omega-6 fatty acids that contribute to the buildup of these materials in the fish."

Tuna, wild or otherwise, is a predatory fish and therefore accumulates lots of mercury. As does cod, halibut, sole, lobster, shrimp, etc. Again, given the choice between red meat and these seafood, the fish are better. Of course, that assumes the fish are not soaked in butter or drenched in a fatty mayonnaise.

The evidence against red meat and dairy, by the way, continues to mount. The recent link of L-carnitine, a by product of meat and whey protein degradation, with inflammatory heart disease, combined with the well established dangers of high saturated fat consumption in terms of heart disease, cancer, stroke, dmentia, etc. should give you meat eaters serious pause for reconsideration.

There's nothing fishy about wild Alaskan Salmon. How about some for dinner?

7 comments:

  1. Are there no other wild fish that one can eat? When I read the title of your blog I thought there would be more than 3 sources named, and among those three only one is fresh and not canned. What about Mahi Mahi, Swordfish, or other ocean fish with scales?

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    1. Unfortunately, there is not a great variety of fish that do not have some meaningful level of contamination. Despite contamination, studies have clearly shown that the benefits of eating fish usually outweigh the risks. Cut and paste the link below into your browser for a summary table of levels of contamination in fish. The higher the number, the safer the fish. http://www.edf.org/sites/default/files/7534_Health_Alerts_seafood.pdf
      As to mahi mahi, it has much less omega-3 than salmon. Swordfish has a high level of contamination and is not recommended.

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    2. Wild lake trout from clean lakes is also a good fish to eat.

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    3. Thank you Dr. Charlap. I enjoy fish; different kinds of fish, salmon and trout being among my favorite. I also like variety...I guess I will have to start working on creating some new recipes, and revisiting recipes I learned when we lived in Alaska. :)

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  2. I purchased frozen wild salmon filets from Costco. I thought they tasted much drier and flat than the farm raised. If butter is not recommended, how do you prepare your wild salmon?

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    1. You may consider olive oil, but go light on it. By the way, good olive oil usually comes in a clear bottle, turns solid when refrigerated, and is picked and bottled in the same country. Choose the extra virgin variety but read the label to make sure where they picked the olives and bottled the oil. Avoid blends. Blends may be diluted with other less healthy oils. California olive oil should have the California Olive Oil Association seal of approval.

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  3. I really like reading on this articles the idea you share is really good full of interesting information.

    Alaskan Fish Species

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