Consumer Reports’ latest tests of 42 samples from cans and pouches of tuna bought primarily in the New York metropolitan area and online confirm that white (albacore) tuna usually contains far more mercury than light tuna. According to Consumers Union, pregnant women should avoid tuna and younger women and kids should limit their consumption.

“Canned tuna, especially white, tends to be high in mercury, and younger women and children should limit how much they eat. As a precaution, pregnant women should avoid tuna entirely,” said Dr. Urvashi Rangan, Director of Technical Policy, at Consumers Union, nonprofit publisher of Consumer Reports.

The Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) advise that women of childbearing age and young children may eat up to 12 ounces a week of light tuna or other “low in mercury” seafood, including, within that limit, up to 6 ounces per week of white tuna.

Consumers Union’s fish-safety experts continue to suggest a more cautious approach, advising pregnant women, as a precaution, to avoid eating tuna because of its potential effects on fetal development. Consumers Union further advises that children who weigh more than 45 pounds limit their weekly intake from 4 to 12.5 ounces of light tuna or from 1.5 to 4 ounces of white tuna, depending on their weight; and children who weigh less than 45 pounds limit their weekly intake from 0 to 4 ounces of light tuna or from 0 to 1.5 ounces of white tuna, depending on their weight.

Consumer Reports’ tests, conducted at an outside lab, found:

• Every sample contained measurable levels of mercury, ranging from 0.018 to 0.774 parts per million (ppm). The FDA can take legal action to pull products containing 1 ppm or more from the market. (It never has, according to an FDA spokesman.)
• Samples of white tuna had 0.217 to 0.774 ppm of mercury and averaged 0.427 ppm. By eating 2.5 ounces (about half a can) of any of the tested samples, a woman of childbearing age would exceed the daily mercury intake that EPA considers safe.
• Samples of light tuna had 0.018 to 0.176 ppm and averaged 0.071 ppm. At that average, a woman of childbearing age eating 2.5 ounces would get less than the EPA’s limit, but for about half the tested samples, eating 5 ounces (about one can) would exceed the limit.

In 2006, Consumer Reports scrutinized [PDF] the results of the FDA’s tests in 2002 to 2004 of mercury levels in hundreds of samples of canned tuna. The agency’s white-tuna samples averaged 0.353 ppm; light tuna, 0.118 ppm. But Consumer Reports found that as much as six percent of the FDA’s light-tuna samples had at least as much mercury as the average in white tuna—in some cases more than twice as much.

Given the uncertainties about the impact of occasional fetal exposure to such high levels, Consumer Reports urged the FDA to warn consumers about occasional spikes in mercury levels in canned light tuna. More than four years later, the FDA still hasn’t issued such a warning. When asked why by Consumers Union, an FDA spokesman indicated to the group that the agency had already taken the spikes into account when formulating its mercury advice.

“The FDA should strengthen its current guidance and advise pregnant women to avoid tuna altogether, especially given the uncertainties about the impact of occasional fetal exposure to high mercury levels,” said Jean Halloran, Director of Food Policy Initiatives at Consumers Union. “The FDA should also continue to test for mercury across the spectrum of fish and seafood in the marketplace in order to provide consumers with adequate information on the mercury levels of all fish.”

Halloran noted that there may well be other species that vulnerable groups like pregnant women should avoid, but the FDA needs to conduct more testing to draw conclusions. “The last set of FDA data gathered from 2002-2004 and published in 2006 needs to be updated and the sample size of many species should be increased,” she said.

Heavy metal accumulates in tuna and other fish in an especially toxic form, methylmercury, which comes from mercury released by coal-fired power plants and other industrial or natural sources. According to Consumers Union, some studies have linked even low-level mercury exposure in pregnant women and young children to subtle impairments in hearing, hand-eye coordination, and learning ability. Other evidence [PDF] suggests that frequent consumption of high-mercury fish might affect adults’ neurologic, cardiovascular, and immune systems. The body is slow to eliminate mercury so it can accumulate in people over time.

Fish are rich in protein, vitamin D, and omega-3 fatty acids. Studies have shown that omega-3s reduce the risk of heart attack and stroke and might also elevate mood and help prevent certain cancers, cognitive decline, and certain eye diseases. During pregnancy, omega-3s might help in developing the fetus’s brain and visual system.

“Fortunately, it’s easy to choose lower-mercury fish that are also rich in healthful omega-3 fatty acids,” Dr. Rangan said. “That’s especially important for women who are pregnant or might become pregnant, nursing mothers, and young children, because fetuses and youngsters are still developing their nervous systems and are therefore at particular risk from methylmercury’s neurotoxic effects.”

Federal agencies advise children and women of childbearing age to avoid four high-mercury fish: king mackerel, shark, swordfish, and tilefish.

So what kind of seafood is safe to eat? According to Rangan, popular seafood, including clams, Alaskan salmon, shrimp, and tilapia, contain relatively little mercury and are better choices. Other lower-mercury choices include: oysters, pollock, sardines, Pacific flounder and sole, herring, mullet, and scallops (with some limitations for women of child-bearing age and children).

The story appears in the January 2011 issue of Consumer Reports and is also available free online.

Photo: Kiruh via Flickr

It is a matter of record that our fish populations are accumulating mercury; and as the top of their food chain, we too are accumulating the toxin.  The neurological effects of mercury have been widely documented.  On the EPA’s website, for example, it lists the primary health effect of methylmercury on fetuses, infants, and children, as being impaired neurological development.

In 2004, a study [PDF] led by Raymond F. Palmer of the University of Texas Health Science Center in San Antonio compared the rate of special education programs in Texas and the amount of mercury found in the environment and the results were alarming: “On average, for each 1000 lb of environmental mercury released, there was a 43% increase in the rate of special education services and a 61% increase in the rate of autism.”

He co-authored a second study [PDF] from February 2008 that took into account the proximity to sources of mercury output — like coal-fired utility plants, which account for 33% of the 158 tons of mercury spewed into the atmosphere annually, municipal/medical incinerators, which account for 29%, commercial/industrial boilers, which account for 18%.  Lower on the list but still noteworthy are hazardous waste sites, cement factories, and the chlorine production plants — which is where the caustic soda tainted with mercury in HFCS is being produced.  This second study found that “for every 10 miles from industrial or power plant sources, there was an associated decreased autism Incident Risk of 2.0% and 1.4%, respectively.”  In other words, the more mercury in the environment of a child or woman of childbearing age, the more likely for the child to develop autism.

The reason that the news on Monday that HFCS contains mercury is so alarming is two fold: First, the FDA had evidence of this in 2005 and did absolutely nothing — no testing, no warning the companies using the tainted HFCS to produce their ketchup, chocolate syrup, cereal bars and soda.  Therefore, more time has passed when mercury could bio-accumulate in our bodies, especially in populations at already at risk for heart disease, diabetes and obesity.  Second, there has been a previous association made between diet and autistic functionality — and specifically HFCS has been singled out as a cause for worsening the disorder. This means that there has been a growing body of evidence relating mercury to autism for some time, in which HFCS is only a new development.

This is dark news, because it means that our FDA is no longer working for us, and that in this time when we might have a receptive ear in Washington, it is more important than ever to challenge the preconceived notions of how government works. This could amount to one of the worst offenses by our government, which has been sitting on the evidence of mercury’s relationship to our health for too long in the name of corporate welfare.

The parents of autistic children should be given more of a voice in this discussion. In an article published on Salon.com in 2005, Robert F. Kennedy, Jr. laid out the details on the correlation between autism and childhood vaccines.  It became clear to him that the parents of autistic children who blamed the vaccines for their child’s disorder were onto something when he stumbled onto a report from a conference in 2000 called Simpsonwood, where high-level officials from the FDA and Center for Disease Control (CDC), the top vaccine specialist from the World Health Organization in Geneva, and representatives of every major vaccine manufacturer, including GlaxoSmithKline, Merck, Wyeth and Aventis Pasteur gathered to discuss a new study that linked a mercury-based preservative in vaccines to increasing rates of autism.  This group, instead of changing course, and giving value to the science before them, proceeded to cover up the data to save the vaccine companies’ bottom line.

Now, we are faced with some hard truth about the consequences of our environmental choices beginning at the Industrial Revolution.  While thimerosal, the mercury-laden preservative used in some vaccinations, is being phased out, we should still be asking for a better assessment of our body burden of mercury.  With all that we know now, about what toxic pollution in the air and water do to our food and by proxy our bodies, will we face facts and begin the process of real, lasting change that the Obama adminstration has so far seemed a beacon for?  The first step will be taking a hard look at environmental mercury, one of the most prevalent pollutants in our environment.  We have a mess on our hands, and we need to begin to repair the damage done before we can move forward healthfully.

The HFCS industry has been shrouded in mystery since it began in the 1970s, essentially the result of “get big or get out” record corn harvests and subsequent plummeting commodity prices for farmers.  What to do with all that excess corn? The answer was not to decrease yields, but to find a way to get that corn into our stomachs.  This has led to the proliferation of HFCS in nearly all processed foods you find in the grocery store.  The industry has lacked transparency, and our government has refused to mediate our current health crisis — an upswing in diabetes and obesity resulting from cheap calories like HFCS — with regulation.  So its not surprising that it took so long for the news to reach the public eye.

The initial study [PDF] led by Renee Dufault, a now-retired Environmental Health Officer-cum-whistleblower, was published yesterday in Environmental Health, and found that nearly half the samples of HFCS tested contained mercury residue. The impetus for the study was to find approximately 58 tons of mercury that was reported missing in 2000 (and it is assumed yearly) from the chlor-alkali plants (makers of chlorine and caustic soda) in operation in the U.S.

Where has it gone? apparently some of it has gone into our veins and tissues.

Before now, our greatest threat for mercury exposure was through fish, followed by mercury amalgam in dentistry and through vaccines, as it is sometimes used as a preservative. But Dufault’s study estimates that exposure via HFCS could be up to 50 times that of mercury amalgam exposure in children age 3-19, as this age group is the largest consumers of HFCS.

Of course we know that mercury is a cumulative toxin, especially dangerous to pregnant women and children, and that those with high exposure (Jeremy Piven among them, from eating too much sushi) show signs of sensory impairment, sensation loss and lack of coordination.  This disorder was formerly referred to as Mad Hatter’s Syndrome, because haberdashers who produced felt hats in the 18th and 19th centuries used a mercury compound in their process.

We too have had a potential day to day exposure to the heavy metal, just by choosing our food from the boxes and bottles in the center aisles of the grocery store.  Aside from the case against us for improper nutrition, we could be slowly poisoning ourselves.

A second study, by David Wallinga, M.D. and his co-authors entitled “Not So Sweet: Missing Mercury and High Fructose Corn Syrup,” [PDF] tested products directly from the supermarket.  One in three tested positive for mercury residue.  These included products like Smucker’s Strawberry Jelly, Hunt’s Tomato Ketchup, Hershey’s Chocolate Syrup, Nutra Grain Strawberry Cereal Bars, Pop-Tarts Frosted Blueberry and Coca-Cola Classic.

The reason Wallinga cited for his extension of the original study was that:

Many of these products are specifically marketed to groups vulnerable to mercury. Soft drinks, fruit juices, and other junk food are successfully marketed to children not only through Internet and television advertising, but also in school vending machine and cafeteria options. People who rely on food stamps or who live in lower socioeconomic neighborhoods are also a special target for junk food manufacturers, because they offer the most accessible and often least expensive calories in the grocery store.

He went on to criticize the FDA for not doing its job, and urged for mercury, which is not required to produce HFCS, to be taken out of the process.  I agree, but I would like to see our government push the corn refining industry further:  They should be shouldering responsibility for our declining health in this country, and as such, should be more adequately regulated.  If it were up to food justice advocates, the substance would be banned outright.  But corn refiners should at least be held accountable for misleading advertising, and consumers should be aware of what they are buying, through better transparency on labels.

So the question is, what will the FDA do with this new found information?  Dufault urges the creation of a mercury surveillance program, that monitors foods besides fish, along with additional public health evaluation of the exposure to mercury through HFCS.  But can we really keep avoiding the deeper problem, that HFCS, as a product of the human imagination, could possibly be a failed experiment?  For the sake of our health, it might be time for the government to finally intervene.