by Marion Nestle

Currently browsing posts about: Fish

Aug 21 2014

Mercury in fish–again. Watch out for tuna.

In June I wrote about the FDA’s advice to pregnant women to avoid eating fish high in methylmercury.  The advisory said to avoid the four fish highest in methylmercury:  shark, swordfish, king mackerel, and tilefish.

I was surprised that the advisory didn’t warn about the high mercury levels in albacore tuna, and I was skeptical about the FDA’s  insistence that pregnant women must eat fish.

Now Consumer Reports advises pregnant women not to eat tuna at all.

Consumer Reports:

So what’s going on here?

In my book, What to Eat, I included a chapter on this very topic: “The Methylmercury Dilemma.”  Here’s a quote:

Albacore tuna clearly belonged on the list of fish to avoid, but advice to restrict its consumption would surely affect the livelihoods of people who fish for, can, and sell tuna.   Because hardly anyone knows the difference between one kind of tuna and another, fish companies worried that consumers would interpret advice to avoid albacore tuna as advice to avoid all tuna.  Industry lobbyists urged the FDA to keep albacore tuna off the methylmercury advisory.   Somehow, albacore tuna got left off.

That was in 2006.   Consumer Reports tells us that pretty much all tuna is too high in methylmercury to be consumed by pregnant women.  So this comment still seems relevant, no?

Evidence: Here’s the response from the National Fisheries Institute:  “Consumer Reports has long history of intentionally mischaracterizing tuna.”

Jun 30 2014

The FDA’s fish advisory for pregnant women: some additional thoughts

When the FDA advisory came out a week or so ago, I started getting questions about whether it meant that women must eat fish during pregnancy and, if so, how much.

As I said in my previous post on the topic, if you like fish, of course eat it, otherwise I can’t think of any compelling reason why anyone has to eat fish.

I view the data on the dilemma caused by omega-3 fatty acids in fish (good) versus the content of methylmercury (bad) as still rather uncertain.  Dr. Malden Nesheim and I discussed this point in an editorial we wrote for the American Journal of Clinical Nutrition [reference 1 below].

Here’s what the FDA advisory says:

Eat 8 to 12 ounces of a variety of fish each week from choices that are lower in mercury. The nutritional value of fish is important during growth and development before birth, in early infancy for breastfed infants, and in childhood… Fish contains important nutrients for developing fetuses, infants who are breastfed, and young children. Fish provides health benefits for the general public. Many people do not currently eat the recommended amount of fish.

This is a prescriptive statement telling pregnant women that they should eat fish.

I would argue that the data on which FDA based this prescription are limited, especially because the results of its scientific assessment are based mostly on theoretical models rather than empirical studies.

Here’s what makes me think some skepticism is warranted:

  1. The effects of even low-level methylmercury exposure may be greater than discussed in the assessment [see reference 2], as the latest analysis from the Environmental Working Group explains.
  2. The increase in young children’s IQ associated with fish-eating during pregnancy is low—-0.7 to a maximum of 3 IQ points.

As the FDA’s assessment report says:

On a population basis, average neurodevelopment in this country is estimated to benefit by nearly 0.7 of an IQ point (95% C.I. of 0.39 – 1.37 IQ points) from maternal consumption of commercial fish. For comparison purposes, the average population-level benefit for early age verbal development is equivalent in size to 1.02 of an IQ point (95% C.I. of 0.44 – 2.01 IQ size equivalence). For a sensitive endpoint as estimated by tests of later age verbal development, the average population-level benefit from fish consumption is estimated to be 1.41 verbal IQ points (0.91, 2.00). The assessment also estimates that a mean maximum improvement of about three IQ points is possible from fish consumption, depending on the types and amounts of fish consumed.

How significant is this?  And does the small benefit in childhood persist into adolescence or adulthood?

  1. The economic question.  Fish are expensive.
  2. The ecological questions.  Advice to increase fish consumption comes up against environmental realities—-overfishing, fish farming—-that make the recommendation impossibly unsustainable [reference 3].
  • The levels of long-chain omega-3s in farmed fish depend on feeding them wild fish, an ecological problem on its own.
  • Guidance about fish can’t be just nutritional; it has to take the economic and ecological impact of fish choices into consideration [reference 4].
  • Current per capita fish consumption is about half the FDA recommended level, and half of that is shrimp.  Fortunately, shrimp don’t have much mercury (although the ones from Asia may have other contaminants), but they also don’t have much omega-3).

All of this suggests grounds for skepticism.  I think a better recommendation would leave more wiggle room to account for uncertainties.  Here’s how I would edit the FDA’s statement:

Pregnant women may eat up to 8 to 12 ounces of a variety of fish each week from choices that are lower in mercury.  Fish are useful sources of nutrients that may have value for growth and development before birth, in early infancy for breastfed infants, and in childhood, and may provide health benefits for the general public.  Other food sources also provide such benefits.

References

[1] Nesheim MC, Nestle M. Advice for fish consumption: challenging dilemmas. American Journal of Clinical Nutrition. 2014;99:973-974.

[2] Karagas MR, Choi AL, Oken E, Horvat M, Schoeny R, Kamai E, Cowell W, Grandjean P, Korrick S. Evidence on the human health effects of low-level methymercury  exposure. Environ Health Perspect. 2012; 120:799-806.

[3] Jenkins D, Sievenpiper JL, Pauli D, Sumaila UR, Kendall CWC  Are dietary recommendations for use of fish oils sustainable? Canadian Medical Association Journal 2009;180: 633-637.

[4] Oken E, Choi AL Karagas MR, Marien K, Rheinberger CM, Schoeny R, Sunderland E, Korrick S  Which fish should I eat? Perspectives influencing fish consumption choices. Environmental Health Perspectives 2012;120:790-798.

Jun 17 2014

Fish politics: The FDA’s updated policy on eating fish while pregnant

Eating fish presents difficult dilemmas (I evaluate them in five chapters of What to Eat).

This one is about asking pregnant women to weigh the benefits of fish-eating against the hazards of their toxic chemical contaminants to the developing fetus.

The Dietary Guidelines tell pregnant women to eat 2-to-3 servings of low-mercury fish per week (actually, it’s methylmercury that is of concern, but the FDA calls it mercury and I will too).

But to do that, pregnant women have to:

  • Know which fish are low in mercury
  • Recognize these fish at the supermarket, even if they are mislabeled (which they sometimes are).

Only a few fish, all large predators, are high in mercury.  The FDA advisory says these are:

  • Shark
  • Swordfish
  • King Mackerel
  • Tilefish

What?  This list leaves off the fifth large predator: Albacore (white) tuna.  This tuna has about half the mercury as the other four, but still much more than other kinds of fish.

The figure below comes from the Institute of Medicine’s fish report.  It shows that fish highest in omega-3 fatty acids, the ones that are supposed to promote neurological development in the fetus and cognitive development in infants, are also highest in mercury.

fish

White tuna is the line toward the bottom.  The ones in the blue boxes are all much lower in omega-3s and in mercury except for farmed Atlantic salmon (high in omega-3s, very low in mercury).

What’s going on here?

  • Tuna producers know you can’t tell the difference between white and other kinds of tuna and don’t want you to stop eating tuna during pregnancy.
  • The data on the importance of eating fish to children’s cognitive development are questionable (in my opinion).  The studies are short term and it’s difficult to know whether the small gains in early cognitive development that have been reported make any difference a few months later.
  • The FDA must be under intense pressure to promote fish consumption.

I think it is absurd to require pregnant women to know which fish to avoid.  In supermarkets, fish can look pretty much alike and you cannot count on fish sellers to know the differences.

Other dilemmas:

  • Even smaller fish have PCBs, another toxin best avoided by pregnant women, if not everyone.
  • The world’s seafood supply is falling rapidly as a result of overfishing.
  • Half of the mercury in seafood derives from emissions from coal-burning power plants.  The best way to reduce mercury in fish is to clean up the emissions from those plants, but plant owners want to avoid the expense.

That’s fish politics, for you.

The FDA documents:

Apr 30 2014

The never-ending fish dilemmas

Mal Nesheim and I have an editorial in a recent issue of the American Journal of Clinical Nutrition: “Advice for fish consumption: challenging dilemmas.”

We commented on a research article evaluating blood mercury levels in adults eating seafood.

In it, we point out that

the 2010 Dietary Guidelines for Americans advise Americans to consume 8 ounces (227 g) of seafood per week to reach an average intake of 250 mg/d of the omega-3 fatty acids EPA and DHA.

This recommendation represents a substantial increase over current consumption amounts of ∼3.5 oz/wk. It is based on “moderate, consistent evidence” that the health benefits of increased seafood consumption outweigh the risks associated with methylmercury, a toxic contaminant of large predatory food fish (tilefish, shark, swordfish, king mackerel) and, to a lesser extent, albacore (white) tuna.

To avoid this toxin, the guidelines advise eating seafood typically found to be low in methylmercury, such as salmon, anchovies, sardines, and trout.

Such advice, however, leads to at least 3 dilemmas. Eating more fish might raise methylmercury intake above safe amounts. Pressures to consume more fish might place impossible demands on an already threatened seafood supply. And the obvious solution—fish farming—raises concerns about what farmed fish are fed and how farmed fish affects the environment.

We urge the 2015 Dietary Guidelines committee to take all this into consideration when making recommendations about fish consumption: “We hope that its advice for seafood consumption will help a confused public resolve some of these dilemmas and make wise seafood choices.”

Wise seafood choices may be an oxymoron, alas.

Nov 27 2013

More on catfish inspection (absurdly enough)

My post yesterday about the politics of catfish inspection inspired comments that I need to better appreciate the superiority of USDA’s import safety program, which requires this checklist for steps that must be taken by importers of meat, poultry, or processed egg products:

  1. Products must originate from certified countries and establishments eligible to export to the United States.
  2. The Animal and Plant Health Inspection Services (APHIS) restricts some products from entering the United States because of animal disease conditions in the country of origin (see APHIS Veterinary Services, National Center for Import and Export).
  3. Countries and establishments become eligible following an equivalence determination process by FSIS.
  4. Imported products must meet the same labeling requirements as domestically-produced products.
  5. After filing the necessary forms for U.S. Customs and Border Protection, and meeting animal disease requirements of APHIS, all imported meat, poultry and processed egg products must be presented for inspection by FSIS at an official import establishment.

It’s not surprising if USDA’s import safety system is better than the FDA’s.  USDA gets $14 million a year to run its currently non-operating catfish inspection system.  The FDA gets $700,000 and, according to the Government Accountability Office, has managed pretty well with it (see yesterday’s post).

Definition is also an issue.  USDA rules apply to all catfish species.  But to protect American catfish producers, the FDA defined catfish as the North American species.  But Vietnam produces different species, which makes catfish inspection even weirder.

Although FDA has had some problems with seafood inspection, it is generally responsible for dealing with fish safety and has had seafood HACCP requirements in place since the mid-1990s.  The USDA does not have authority over fish; it is responsible for the safety of meat and poultry.

Why should catfish be an exception?

Why are we even talking about which agency should be in charge of inspecting catfish?

If the politic fuss over catfish inspection reveals anything, it is why we so badly need a single food safety agency—one that combines and integrates the food safety functions of USDA and FDA—to ensure the safety of the American food supply.

Addition, November 28: Members of Congress urge repeal of the USDA’s catfish inspection program.

Nov 26 2013

The hooks and lines of the farm bill: Catfish inspection

As I am endlessly complaining, the farm bill is so detailed, complicated, and opaque that no rational person can possibly understand it, let alone a member of Congress.

To wit: catfish inspection.

As Gail Collins noted in her New York Times column a week or so ago, some members of the House want the USDA to inspect catfish, not the FDA (which ordinarily is responsible for fish inspection).  The current FDA inspection office costs $700,000 per year.  The USDA office, established by the 2008 farm bill, costs about $14 million a year, even though the USDA has not gotten around to issuing rules or actually inspecting catfish.

What is this about?  Not fish safety, really.  It’s about protecting catfish farmers in the South and setting up “more rigorous” safety criteria that will exclude competitive foreign catfish imports, especially from Vietnam.

The House version of the farm bill calls for repeal of USDA catfish inspection as a cost-cutting measure (the Senate farm bill does not mention catfish inspection, which means it leaves the USDA office in place).

Thad Cochran, Republican Senator from Mississippi, wants the House to delete the repeal provision, keep USDA in charge, and, thereby, protect the Mississippi catfish industry from foreign catfish imports.

Politico Pro quotes a member of Cochran’s staff:

Sen. Cochran has made it clear that his priority is to complete the new farm bill and get it signed into law. It sounds like there are some who have a deep under-appreciation of the diversity of Mississippi’s agriculture industry and the importance of this bill to the state’s farmers, foresters, hunters, and those in need of nutrition assistance.

The New York Times also points out that although some watchdog consumer groups support tougher safety standards for catfish (because of lower foreign standards for antibiotics and other chemicals), a Government Accountability Office report in May 2012 called imported catfish a low-risk food and said an inspection program at the Agriculture Department would “not enhance the safety of catfish.”

Now, says the Times in another article, a coalition of budget watchdog groups and a seafood trade group are lobbying to repeal the USDA’s inspection program.

All of this is in the House version of the farm bill, but unless you are a lobbyist for the catfish industry, you would never know it from the bill itself.  Here’s the relevant section from the  House bill.

catfish

As Gail Collins puts it,

See, this is what I like about the farm bill. The agriculture parts harken back to the golden era when Republicans and Democrats could work together to promote stupid ideas that benefited the special interests in their districts. And then go out and get inebriated in bipartisan drinking sessions. Now everybody is in the gym and then shutting down the government.

Apr 2 2013

Retailers and the GM salmon problem

A coalition of consumer, health, food safety and fishing groups behind the “Campaign for Genetically Engineered (GE)-Free Seafood” is recruiting grocery store chains to agree not to sell genetically engineered seafood even if the FDA allows it to be sold.  The campaign is aimed at the genetically modified AquaBounty salmon, which the FDA has had under consideration for ages, with no decision in sight.

The stores that have pledged not to sell GM salmon include Trader Joe’s (367 stores), Aldi (1,230 stores), Whole Foods (346 stores in U.S.), Marsh Supermarkets (93 stores in Indiana and Ohio), and PCC Natural Markets (9 stores in Washington State) and co-ops in Minnesota, New York, California, and Kansas.

This is a big deal because other GM seafood are in the research pipeline.  Large percentages of Americans say they oppose GM seafood and that the FDA should not allow it to be marketed.

And if the FDA does approve it, the agency is highly unlikely to require any special kind of labeling.

This reminds me of what happened to genetically modified tomato paste in the U.K.  Supermarket chains were selling the cans with labels clearly indicating that they were “produced from genetically modified tomatoes.”  The stores priced them favorably, and customers bought them — until Monsanto shipped unlabeled corn to Great Britain and caused a furor.

Retailers decided that they had plenty of tomato paste, didn’t need upset customers, and refused to continue selling the GM varieties.

Retailers call the shots in this situation.

I think much of the public distress over GM foods is because of lack of transparency.  Without labels, customers cannot exercise freedom of choice.

Just label it!

 

Jan 10 2013

Predictions for 2013 in food politics

For my monthly (first Sunday) Food Matters column in the San Francisco Chronicle, I devote the one in January every year to predictions.  Last year I got them all pretty much on target.  It didn’t take much genius to figure out that election-year politics would bring things to a standstill.  This year’s column was much harder to do, not least because the FDA was releasing blocked initiatives right up to the printing deadline.

 Q: I just looked at your 2012 crystal ball column. Your predictions were spot on. But what about 2013? Any possibility for good news in food politics?

A: Food issues are invariably controversial and anyone could see that nothing would get done about them during an election year. With the election over, the big question is whether and when the stalled actions will be released.

The Food and Drug Administration has already unblocked one pending decision. In December, it released the draft environmental assessment on genetically modified salmon – dated May 4, 2012. Here comes my first prediction:

The FDA will approve production of genetically modified salmon: Because these salmon are raised in Canada and Panama with safeguards against escape, the FDA finds they have no environmental impact on the United States. The decision is now open for public comment. Unless responses force the FDA to seek further delays, expect to see genetically modified salmon in production by the end of the year.

Pressures to label genetically modified foods will increase: If approval of the genetically modified salmon does nothing else, it will intensify efforts to push states and the FDA to require GM labeling.

Whatever Congress does with the farm bill will reflect no fundamental change in policy: Unwilling to stand up to Southern farm lobbies, Congress extended the worst parts of the 2008 farm bill until September. Don’t count on this Congress to do what’s most needed in 2013: restructure agricultural policy to promote health and sustainability.

The FDA will start the formal rule-making process for more effective food safety regulations: President Obama signed the Food Safety Modernization Act in January 2011. Two years later, despite the FDA’s best efforts, its regulations – held up by the White House – have just been released for public comment. Lives are at stake on this one.

The FDA will issue rules for menu labels: The Affordable Care Act of 2010 required calorie information to be posted by fast-food and chain restaurants and vending machines. The FDA’s draft applied to foods served by movie theaters, lunch wagons, bowling alleys, trains and airlines, but lobbying led the FDA to propose rules that no longer covered those venues. Will its final rules at least apply to movie theaters? Fingers crossed.

The U.S. Department of Agriculture will delay issuing nutrition standards for competitive foods: When the USDA issued nutrition standards for school meals in January 2012, the rules elicited unexpected levels of opposition. Congress intervened and forced the tomato sauce on pizza to count as a vegetable serving. The USDA, reeling, agreed to give schools greater flexibility. Still to come are nutrition standards for snacks and sodas sold in competition with school meals. Unhappy prediction: an uproar from food companies defending their “right” to sell junk foods to kids in schools and more congressional micromanagement.

The FDA will delay revising food labels: Late in 2009, the FDA began research on the understanding of food labels and listed more relevant labels as a goal in its strategic plan for 2012-16. Although the Institute of Medicine produced two reports on how to deal with front-of-package labeling and advised the FDA to allow only four items – calories, saturated and trans fat, sodium and sugars – in such labels, food companies jumped the gun. They started using Facts Up Front labels that include “good” nutrients as well as “bad.”

Will the FDA insist on labels that actually help consumers make better choices? Will it require added sugars to be listed, define “natural” or clarify rules for whole-grain claims? I’m not holding my breath.

Supplemental Nutrition Assistance Program participation will increase, but so will pressure to cut benefits: Demands on Snap – food stamps – reached record levels in 2012 and show no sign of decline. Antihunger advocates will be working hard to retain the program’s benefits, while antiobesity advocates work to transform the benefits to promote purchases of healthier foods. My dream: The groups will join forces to do both.

Sugar-sweetened beverages will continue to be the flash point for efforts to counter childhood obesity: The defeat of soda tax initiatives in Richmond and El Monte (Los Angeles County) will inspire other communities to try their own versions of soda tax and size-cap initiatives. As research increasingly links sugary drinks to poor diets and health, soda companies will find it difficult to oppose such initiatives.

Grassroots efforts will have greater impact: Because so little progress can be expected from government these days, I’m predicting bigger and noisier grassroots efforts to create systems of food production and consumption that are healthier for people and the planet. Much work needs to be done. This is the year to do it.

And a personal note: In 2013, I’m looking forward to publication of the 10th anniversary edition of “Food Politics” and, in September, my new editorial cartoon book with Rodale Press: “Eat, Drink, Vote: An Illustrated Guide to Food Politics.”

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