Day: October 17, 2006

Fish good for You? – this byline stinks

BBC NEWS | Health | Benefits of fish ‘outweigh risks’

Dariush Mozaffarian, lead author of the study said: “Overall, for major health outcomes among adults, the benefits of eating fish greatly outweigh the risks.

“Somehow this evidence has been lost on the public.”

Concerns have been raised about chemicals found in fish from pollution.

These include mercury, polychlorinated biphenyls (PCBs) and dioxins.

And in other news, “breathing is good for you”. Please, I can’t take this any more. The question is NOT, and NEVER WILL BE, “Is fish good for you?”. Of course it is. The question is: “What kind of fish is good for you, and whether appropriate labeling can help the consumer decide”.

At least in the US of A, which is where I have eaten the bulk of my fish, the primary source of information you can get about eating fish is on the web and for North Carolina, here. So, you’re supposed to go around with a checklist of good and bad fish in your head when you go to the grocery store. Most consumers do not have this kind of information, especially when there are so many categories to choose from. Is it fatty, or non? Is it freshwater or marine? Is it canned, fresh or frozen? Is it caught or farmed? Canned light tuna is okay, but canned albacore tuna is not, can you remember this when shopping for 30 other things at the store?

Confused enough? How about, tilefish at 3.99 a pound versus salmon at 7.99 a pound? What will you buy on a tight budget?

If you’re the average consumer, you have a minute to decide whether it’s fish for dinner, or something else, unless you’re carrying around this handy checklist in your hand/PDA (in which case you’re not the average consumer), you have two opposing thoughts in your head….

  1. I know that fish is good for me, so I need to eat more fish
  2. I know that certain fish is not good for me, especially if I’m pregnant/nursing/feeding kids – But I don’t know if this fish that’s on sale is on the safe list, or not.

What will you do given that you have one minute to decide, you have no information in the store, and you have no one in the store looking out for you?

And this paper wonders, and I paraphrase,

“Somehow this evidence has been lost on the public”

Labeling is important, information is power, if you’re buying fish, you want to know where it is from, what the average pollutant loadings of the fish from this area are, and what the advisory on this fish is, so you can make an informed choice in the one minute that you have. This has been widely researched, and the information is easily available (on the web, where you don’t shop for groceries). Is it too much to ask for a list to be posted wherever fish is sold? I guess it “hurts business”.

Personal responsibilty is accepted, but if you do not give people the tools to make informed choices, it’s just a cynical ploy to shift blame, shift burden, and shift risk.

This paper deserves to be read in full, so here’s the abstract. Needless to say, the study, funded in full by tax payer money through the National Heart Lung and Blood Institute, is behind a subscription wall.

Fish Intake, Contaminants, and Human Health

Evaluating the Risks and the Benefits

Dariush Mozaffarian, MD, DrPH; Eric B. Rimm, ScD

JAMA. 2006;296:1885-1899.


Context  Fish (finfish or shellfish) may have health benefits and also contain contaminants, resulting in confusion over the role of fish consumption in a healthy diet.

Evidence Acquisition  We searched MEDLINE, governmental reports, and meta-analyses, supplemented by hand reviews of references and direct investigator contacts, to identify reports published through April 2006 evaluating (1) intake of fish or fish oil and cardiovascular risk, (2) effects of methylmercury and fish oil on early neurodevelopment, (3) risks of methylmercury for cardiovascular and neurologic outcomes in adults, and (4) health risks of dioxins and polychlorinated biphenyls in fish. We concentrated on studies evaluating risk in humans, focusing on evidence, when available, from randomized trials and large prospective studies. When possible, meta-analyses were performed to characterize benefits and risks most precisely.

Evidence Synthesis  Modest consumption of fish (eg, 1-2 servings/wk), especially species higher in the n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), reduces risk of coronary death by 36% (95% confidence interval, 20%-50%; P<.001) and total mortality by 17% (95% confidence interval, 0%-32%; P = .046) and may favorably affect other clinical outcomes. Intake of 250 mg/d of EPA and DHA appears sufficient for primary prevention. DHA appears beneficial for, and low-level methylmercury may adversely affect, early neurodevelopment. Women of childbearing age and nursing mothers should consume 2 seafood servings/wk, limiting intake of selected species. Health effects of low-level methylmercury in adults are not clearly established; methylmercury may modestly decrease the cardiovascular benefits of fish intake. A variety of seafood should be consumed; individuals with very high consumption (≥5 servings/wk) should limit intake of species highest in mercury levels. Levels of dioxins and polychlorinated biphenyls in fish are low, and potential carcinogenic and other effects are outweighed by potential benefits of fish intake and should have little impact on choices or consumption of seafood (women of childbearing age should consult regional advisories for locally caught freshwater fish).

Conclusions  For major health outcomes among adults, based on both the strength of the evidence and the potential magnitudes of effect, the benefits of fish intake exceed the potential risks. For women of childbearing age, benefits of modest fish
intake, excepting a few selected species, also outweigh risks.