Fish: friend or foe

One of my pet peeves in the world of science communication is the constant barrage of contradictory nutritional information. Dairy will kill you. All that saturated fat. The hormones and antibiotics. But the calcium! But the vitamin D! The heart disease-fighting conjugated linoleic acid! Fiber is good for you! Nope, it doesn't do crap. Ahahah, you're all going to die! Food in pill format is the future! Nothing you do can will protect you! Mwahahahaha...

Today, the New York Times (and everyone else in the world) carried an intriguing story about two reports on the health benefits of eating fish. One from the Harvard School of Public Health, the other from the National Institutes of Health. Both well-respected organisations filled with lots of big-brained folk who have our best interests at heart (cough).

Anyways. Harvard prof Dariush Mozaffarian (famous for his work with trans-fats) has concluded - via a literature search - that eating fish 1-2 times per week can cut heart disease death risk by 36% and overall mortality risk by 17%. Their findings are reported in the Journal of the American Medical Association. The NIH dudes figure that eating fish might reduce the risk of cardiovascular disease...but that has to be balance by the risk of mercury-poisoning and carcinogenic polychlorinated biphenyls and dioxins. Pdfs of their press release, report and fact sheet are here.

From the NIH graphs on levels of mercury/DHA&EPA (the omega 3 fatty acids) for different marine species, we can conclude that farmed Atlantic salmon is the bestest - the highest in god oils and the lowest in mercury. Wild Atlantic salmon isn't far behind in the omega category and then you don't have to eat all the growth hormones, antibiotics, sea lice and seriously high levels of toxins.

So what's a girl to do, eh? Let's start with what everyone agrees on. Mercury is bad. We shouldn't eat too much least we all get mad as hatters, especially when pregnant. Omega 3s are good. They might ward off depression, aggressive behaviour, fight Alzheimer's and memory loss, help neural development and keep hearts pumpin' good.

The solution, to me, is modest consumption of low toxin/mercury fish (like wild salmon) and fish oil pill supplements. Supposedly the "good" quality pills remove all the contamination, hence why they cost a bleeding arm and a leg. You can also get DHA-enriched eggs or purified DHA from algae..but then who knows what we are missing by eating purified supplements instead of the whole deal.

Of coure someone could try and STOP ALL THE BLEEDING MORONS FROM CONTAMINATING THE OCEAN TO BEGIN WITH. Sadly, that does not come in pill format.

Comments

[Lab Lemming]

"Supposedly the "good" quality pills remove all the contamination, hence why they cost a bleeding arm and a leg. "

Oh, sure, the health suppliments industry never tries any misleading or deceptive practices by ignoring potential side effects. And they never fail to adequately test their products. Unless there is a spec concentration printed on the bottle, I won't trust the suppliments to have undergone any sort of Hg removal.

Afterall, natural calcium suppliments often contain harmful levels of Pb (lead, not peanut butter). Oyster shells are a classic example. But if it is an unregulated, natural product, there is no way to tell.

[Paul]

I agree: this study is the least bit ridiculous... and clearly bankrolled by the mackerel-industrial complex.

[Anna]

Yah, the natural products industry can be pretty crap. But Consumer Reports did a test of 16 commerically available fish oil pills in 2003 and found that none of them had "worrying" levels of mercury, PCBs or dioxins. But it's not surprising that mercury is not found in fish oil - it actually binds to the protein..this is also why you cannot reduce exposure to mercury via fat-trimming or grilling. These two methods do reduce the amount of fat-stored PCBs and dioxins. So it's likely the organic pollutants that are a problem for the oils.

That being said, no one is monitoring or required to measure. I mean check this label:

Specifications for Enzymatic Therapy ESKIMO-3 Fish OIL
...Eskimo-3 is also purified by a proprietary process that preserves the beneficial active constituents of the whole oil, and contains no detectable dioxin, DDT, PCB, heavy metals or toxins present in many commercial fish oil preparations. Many fish oils have been found to contain varying levels of these harmful substances. Eskimo-3 has been shown by an independent laboratory to be free of these contaminants.

Says who again?

[donna]

Wild salmon is the food of the gods. My next life, I want to be an Alaskan Brown Bear...

Or maybe a golden retriever. Or a dolphin.

Sigh. So many choices!

[mr. orange]

Not to be a spoilsport, but Oceans Alive says unequivocally that *no one* should be eating Atlantic Salmon:

http://www.oceansalive.org/eat.cfm?subnav=fishpage&fish=85

it gets a "worst" rating for both ecological and health reasons

[MDude]

Just pass al your fish through a big magnet. Like the kind used for MRI scans.

[Lab Lemming]

On a related point, a women I met at a conference in August works in a UK lab, but also occasionally teaches. One of her teaching labs has students bring in their favorite bottled water, and test the metals.

She used to really like this test because one of the fancy European fizzy waters (Dom Perrigon, I think) was consistently double the UK limit for uranium. Then the EU raised the standard from 2 to 10 ppb, so it suddenly became safe.

[Anna]

Sweet. Maybe we can start selling it at a really high price to Iran.

[Jonathan]

Is a trans-fat a fat that feels trapped in the molecular structure of a carbohydrate?