Thursday, October 04, 2007

Tainted science about mercury in fish

A new study suggests pregnant women should eat more fish than government agencies advise. But look who's talking.

The Healthy Mothers, Healthy Babies coalition produced the study, with funding from the National Fisheries Institute. But wait, isn't that the advocacy arm of the seafood industry? The NFI website says the group is "A trade Association committed to assisting its members to succeed in the global seafood marketplace." that a conflict of interest? Might the advice be skewed to assist NFI members to succeed in the marketplace?

The Healthy Mothers, Healthy Babies coalition looks credible with membership that includes the American Academy of Pediatrics and the March of Dimes, the Centers for Disease Control, and subunits of the National Institutes of Health. Interestingly, some of the most credible coalition members are now backing away from the new mercury advice, including the American Academy of Pediatrics and the March of Dimes, the Centers for Disease Control, and the National Institutes of Health.

At this time, with the story just hours old, we can't be sure what the truth is. This will take some time to sort out. But the new "eat more fish" advice is not quite what it seemed earlier today, and I have a feeling this is going to play out badly for the seafood industry.

I love fish, I eat a lot of fish, and I think it's healthy food. But I know a bit about mercury in fish and my wife is an environmental toxicologist and we agreed she should not eat fish just before pregnancy, during pregnancy, and while nursing because we studied the risks and the mercury risk is too high. Now she gladly eats fish again with me. We're very cautious in what seafood we feed our young children (3 and 6 yrs old).

Mercury risks in seafood are real. They shouldn't scare people away from seafood. But the seafood industry MUST BE STRAIGHTFORWARD AND HONEST about these risks or they may burn bridges with consumers. Mercury in seafood is a real risk to pregnant women. Admit it and move on.

Will this new advice turn into a fiasco that harms public confidence? It's too soon to tell. But the National Fisheries Institute isn't doing the industry any favors with this apparently ham-handed effort to push seafood on pregnant women.

Blogfish has been here before, and I think we'll end up back here again, on the seafood/mercury carousel.


Anonymous said...

I was disappointed by the title, the tone, and the anecdotal ("my wife is a toxicologist") nature of this post. A number of respected reports including those from the Harvard Center for Risk Analysis, an article by Hibbein et al 2007 in Lancet and the Academy of Sciences Nutrient Relationships In
Seafood: Selections To Balance Benefits And Risks" all support the information that was quoted form the press release.
In essence the health risk of not eating fish does not outweigh the health benefits of eating fish as long as the national consumptionadvisories are followed. The point of the report gets at exactly what happened in your family. Reports of mercury tainted fish scared women from eating any fish during pregnancy. According to the Hibbein study "maternal seafood intake during pregnancy of less than 340 g was associated with with increased risk of their children being in the lowest quartile for verbal IQ". And from the summary:"Maternal consumption of less than 340 g per week in pregnancy did not protect children from adverse outcomes; rather we recorded beneficial effects on child development with maternal seafood intakes of more than 340 g/week., suggesting that advice to limit seafood consumption could actually be detrimental".
Women, children, men, should all be eating fish in moderation and in accordance with Institute of Medicine recommendations.
This blog has pointed out on numerous occasions that it is difficult to move from "conventional wisdom" to a new paradigm. The new paradigm is that fish a better for you than you think.

Mark Powell said...

My good friend, reasonable people can disagree on how to respond to risk. That's why I cited my wife's expertise, to demonstrate that we didn't react purely out of emotion, rather we reviewed for ourselves the risk and made our own decision on whether she would eat seafood during pregnancy and while nursing.

In order to ensure good health, for herself and our kids, she was very conscious of her diet and I doubt very much that not eating seafood was a problem, because she compensated with other foods.

Your tone and attitude seems to suggest that you don't want us making our own decisions, rather you want everyone to follow some authority's advice. Not smart. Anyone in the know is aware that choice of health endpoints and tolerable risk levels is critical in the advice produced, and reasonable people can disagree on those choices. Hence, reasonable people can reach different reasoned conclusions based on the same data. That's called science.

You missed the main point, anonymous, what do you think about the problems raised with the conduct and announcement of yesterday's advice from the Healthy Mothers, Healthy Babies Coalition?

I think it will be interesting to see what comes up over the next few days and weeks regarding this announcement and the underlying study. The advice may turn out to be a reasoned review of the data, or it may turn out to be biased, we don't know yet. There are some concerns that make the appear to make the advice questionable at this time. The science is tainted by bias and incorrect citing of support. It may turn out that the taint doesn't ruin the conclusion, but then again, following the taint may uncover a flawed conclusion.

Anonymous said...

Its interesting how we can almost be saying the same thing but have such large differences. You said "Your tone and attitude seems to suggest that you don't want us making our own decisions, rather you want everyone to follow some authority's advice. Not smart."

Exactly. It was "not smart" in retrospect to listen to all the "authorative" rhetoric that frightened people away from eating fish because it turns out we did not have all the information to "make our own decision" and probably still don't because the positive aspects of fish consumption are not as newsworthy. as the negative. The "average" child bearing female is probably still forgoing the health benefits of fish in the belief she is doing the right thing even though the there has been considerable evidence compiled to the contrary.

Mark Powell said...

It's not only rhetoric that turns pregnant women away from seafood. Mercury risks are a problem because harm is nasty (brain harm), delayed, and not obvious at the time. Careful nutrition can replace seafood benefits without incurring the risks of brain damage in your kids. In such a situation, it can be a well-reasoned decision to avoid seafood during pregnancy and nursing.

You seem biased, anonymous, when you say people "should" be eating seafood, that seafood is better for you than you think, and that people are frightened away from seafood inappropriately.

Remember, you're talking to a seafood lover here, and I DO think seafood is healthy food. But we shouldn't ignore or dismiss risks.

Anonymous said...

I think it's also important to point out that while reports of high mercury levels in fish may have frightened some, the FDA and most respected NGOs working on the subject never said "Don't eat fish if you're pregnant."

Instead, they advised women to eat no more than 12 ounces per week, to choose fish with low average mercury content, and to avoid fish with high mercury content. In fact, two of the fish recommended by HMHB are on the FDA's "Do not eat" list for pregnant women.

I feel a bit more strongly than you I think, Mark, about the corrupt funding of this "study," but I really appreciate this post. Good reporting! I linked to you from my post on Enviroblog.

Anonymous said...


As a business owner in the seafood business.....we have to depend on experts......We depend on Dr Charles Santerre at Purdue University for seafood contaminate information....also a food scientist, with many years of seafood experience. Could you speak with Dr we have used your information to help develop our sustainability programs, we have used Dr Santerre for mercury direction. It would be helpful if we could get a clearer direction than what I have interpretted from your blog.

I believe Dr Santerre will say that pregnant and nursing women and children under 7 need to eat fish......but need to avoid "mercury rich" fish(he has a little card that assist in the selection of mercury safe fish). Furhter Dr Santerre will discuss that avoiding fish for these groups is not a healthy choice. Your blog suggest avoidance is best. As a result, two experts that I depend on are at opposite ends....please help us with this clarification.....

Bob @ Plitt Seafood

Mark Powell said...

Bob, Thanks for your comment, I apprecate the work you've done as a seafood businessman to pursue sustainability and to be up front about mercury issues.

I will check with Charles Santerre, and I'll report here on blogfish what I find.

I do not know of any reason why pregnant women MUST eat seafood. It is my understanding that adequate omega-3 faty acids can be consumed from other sources. This drives much of my reasoning.

I support the FDA advice as the best scientific recommendation. However, I have concerns that the guidelines may not be protective enough. European standards set lower limits on the allowable levels of mercury in most fish, and there is scientifc debate on this subject. Some studies suggest the FDA advice is not adequately protective. Also, studies of mercury levels in fish have found high variability among individual fish of the same species.

So the FDA guidance may not prevent harmful mercury exposure for vulnerable populations (pregnant and nursing women and young children).

This leads me to higher personal levels of caution that can not be fully justified with scientific proof. Hence my support for the FDA guidance for people who want to rely on the state of the science.

In essence, my comments rely on my own, more stringent mercury standard because I place a very high emphasis on avoiding mercury risks since the harm from mercury is irreversible, unclear at the time seafood is eaten, and avoidable.

I have not evaluated the advice released this week, but the problems with the study and announcement make me very skeptical of advice to pregnant women to eat more seafood than FDA guidelines.

As I've said before, I love seafood and believe it is very healthy food, and I eat some seafood nearly every week, sometimes multiple times per week.

I wish more people in the seafood business would be like you, Bob, and deal with these issues openly and without bias.

More to come after I contact Charles Santerre. Thanks again for your concern and attention to these important issues.


Mark Powell said...

Bob, Regarding my view of chemical risks: I buy mostly organic food even though the need is not proven conclusively. I would recommend the same to others.

I understand that reasonable people can differ on such issues, and make different choices.

In fact, I'm a bit of a chemical-phobe in general. I don't use toxic cleaners in my house where I can avoid them, I don't use bug repellant, etc., etc. Recently, I even bought a special natural fiber mattress for my daughter that does not release fumes from chemical solvents or flame retardants. I didn't balance the benefits of flame retardants vs. the risks, I just plan to avoid fire risk through teaching her safe habits to avoid ignition of her mattress.

So my mercury concerns are in the context of my broader efforts to PREVENT exposure to toxic chemicals whenever possible.

I don't know if that helps explain my views on mercury in seafood.


Anonymous said...


not to take up your blog space......but .......while you are talking to Dr mentioned that you can get Omega 3 from other soureces......ok, this is where I leave my comfort it true, that fish is the only source of 2 important components of Omega 3....something called EPA/DHA (acronyms for something I can't spell) impression is that you can consume Omega 3 rich foods....but if it is absent EPA/DHA, you are not getting the whole enchilada.....if you could also sove this for me it would be sum it up:

1. Are women best to avoid fish when pregnant or nursing.....same for kids under 7.......or is the avoidance of fish a far riskier strategy than the avoidance of fish mercury?

2. Omega all Omega 3 created equal

3. Finally, is it ok to air my questions on your site

Mark, I respect all you do,,,,,,these are very complex issues......I realize I am looking for a easy answer.....but easy answers help Plitt and our customers provide an easy strategy......we all want to do the right thing.....thanks for your help Mark

Bob @ Plitt

Mark Powell said...

Bob, Thanks for raising this here. We could talk about it privately, but others may (probably do) have the same questions. My hope for blogfish is to be a forum for this type of conversation, so please keep posting here.

BTW, I discussed these issues with my wife, and her memory is that she ate salmon during pregnancy and nursing, but at reduced levels (we normally eat a lot of salmon).

Regarding the details of omega-3 in understanding is that EPA/DHA are valuable omega-3s that are present in seafood but not in other dietary sources of omega-3s. Our bodies can make EPA/DHA but western diets (e.g. grain fed beef) can include so much omega-6 fatty acids that EPA/DHA synthesis can be too low.

Based on this understanding, I view seafood as valuable but not completely essential. A good diet rich in omega-3s from other sources will likely allow our bodies to make enough EPA/DHA.

I think I should change my view on the proper role of seafood in pregnancy for people with average American diets. Such people are likely to need seafood-derived omega-3s. I forgot to consider the average poor diet and it's tendency to suppress synthesis of long chain omega-3s.

Mark Powell said...

The final word(?) I talked with Purdue University scientist Charles Santerre, and I'm ready to recommend his website for the final word on seafood and mercury, given current understanding of the issues.

He recommends modest amounts of low mercury seafood for women who are pregnant or nursing. He has a wallet card you can download that puts seafood into low, medium, and high mercury categories, and it's easy to follow.

This is the best, most credible advice that I've found, and I think pregnant and nursing women should eat some seafood.

Anonymous said...

Mark - it took you a while to get there but glad to see you were able to examine the scientific evidence that is emerging regarding fish consumption and shift your views.
Maybe there is hope.
The First Anonymous

Mark Powell said...

There's always hope, anonymous 1! I'm happy to learn from this forum, that was one of my reasons for starting blogfish.

Danny Ray said...

I wholeheartedly agree that the "Healthy mothers" campaign is more about PR from the fish industry than about public health.

I think there is a grave danger in believing someone just because that person is a scientist. (This has nothing to do with Dr. Santerre who sounds very reasonable by Bob@Plitt's entry). "Scientists" long claimed that lead was safe in gasoline and that cigarettes were good for health.

More important is the data. There have been several very good studies on the effects of low level mercury exposure on the developing fetus. The most convincing comes from the Faroe Islands where the villagers tend to eat whales. 2 other important data sources are from industrial accidents - one in Minimata Bay in Japan, and another from contaminated grain in Iraq.

Using these studies, the National Academy of Science and the EPA have independently reached conclusions about safe reference doses of mercury consumption. They have then gone back and figured out how much fish can be safely consumed in order to stay below these reference doses.

So why would I believe some scientist from the fish industry who then says that people should eat more than recommended by the EPA and NAS? Are they saying that these studies are bogus? They are basing their PR on a desire to sell more fish, not on health concerns.

The fish industry would be better off lobbying against coal powered power plants and incinerators than in trying to confuse the public about safe levels of mercury in fish.