The latest Scare du Jour: mercury in HFCS

Our bodies are designed and have adapted to thrive on the planet earth. As such, our bodies naturally detoxify and can deal with elements, minerals, chemicals and even bugs, found naturally in our foods and environment. We’re made of tough stuff and not nearly as wimpy and vulnerable as some want us to fear. That resilience is a good thing for the survival of the human species!

There will always be people who try to scare us about some food (it’s always something they don’t think we should eat) by telling us a small amount of some “toxin” — or “neurotoxin” (that sounds even scarier) — has been detected. This is our heads up that we are being manipulated and someone’s trying to take advantage of the fact a lot of people think a chemical or toxin means danger.

With the refinement of modern scientific instrumentation, it is now possible to detect the tiniest traces of things in our bodies and foods — down to parts per billion. That means, there are even more things to try and scare us with. But just because something can be detected does not make it dangerous. Everything is toxic in high enough doses — including water, salt, iron or polonium — but perfectly safe at the levels we typically encounter them. The core principle of pharmacology and toxicology is “the dose makes the poison.”

The scare in the news this week combines two currently trendy evils: mercury and high fructose corn syrup (HFCS) — but attempts to worry us about the findings of a new study make no biological or scientific sense. Since the mainstream media isn’t reporting the science and is only giving the press release version, at reader request, let’s take a quick look at the facts.

The new study in the news was published in Environmental Health, an online open-access publication of BioMed that allows any member to publish an article for a fee. It was led by Renee Dufault, MAT [masters of art in teaching], at United Tribes Technical College in Bismarck, ND. Briefly, 20 samples of HFCS gathered in February 2005 were tested for mercury at the University of Wisconsin-Platteville. The average levels of mercury in the samples were 0.113 parts per million (μg/gram). In eleven of the samples, the levels were below the level of detection even using the most sophisticated equipment.

This led them to call for FDA testing of all foods containing HFCS for mercury and labeling to inform the public of “any detections.” The reason they gave is because “mercury in any form… is an extremely potent neurological toxin.” No exposure is the only safe exposure, they said.

Understanding science is the only way to protect ourselves from being continuously and needlessly scared. There were at least three inaccuracies in this story. Did you catch them?

Exaggerated consumption. To heighten concerns, the authors claimed that it “may be necessary to account for this source of mercury in the diet of children and sensitive populations” because the average daily consumption of HFCS is about 50 grams per person in the United States.

This claim, however, incorrectly used industry supply and production data from the Market and Trade Economics Division at the USDA’s Economic Resource Service to extrapolate actual dietary consumption among Americans. ERS data has been repeatedly been shown to be faulty and to wildly exaggerate what people really eat. For example, as we know, it doesn’t account for exports and only estimates waste. National Health and Nutrition Examination Surveys (NHANES) conducted by the U.S. Centers for Disease Control and Prevention, based on nationally representative dietary assessments, has been recognized among medical professionals as the most reliable data available on the foods eaten by Americans. Even still, the ERS data shows that market levels for HFCS in 2007 were unchanged from the early 1990s, with no statistical changes in total sweeteners during that time. In other words, we’ve been consuming this amount of sweets for decades. It turned out to be irrelevant, except the use of ERS data was our clue that something other than clinical understanding of nutrition was going on.

Failing to understand that all forms of mercury are not the same. Mercury is one of those ubiquitous elements on our planet and humans have always been exposed to low levels. It is everywhere, naturally. So, medical scientists know and, as expected, have always found mercury in food and in everyone’s bodies — bodies of normal, healthy people.

But an important fact the media has left out of this story is that elemental mercury is not a health threat when ingested (or handled) because virtually none (less than 0.1%) is absorbed through the digestive tract (or skin).

“The body does not readily absorb liquid mercury through the skin or stomach,” according to the Agency for Toxic Substances and Disease Registry. A fact confirmed by every scientific agency. “Virtually no elemental mercury is absorbed from the gastrointestinal tract or by the skin,” said the ATSDR.

So, the 0.113 ppm of mercury purportedly in HFCS makes even less sense to panic over. Even more, it’s biologically implausible for 0.000113 part per million that might be digested to be dangerous. We’d have to eat impossible quantities to get enough to worry about.

Only when breathed in and absorbed through the lungs, high levels of mercury vapor can be harmful. However, vaporization occurs very slowly over time, and the Association for Science Education in the UK reports that negligible amounts of mercury are released from small beads of mercury from old thermometers even after 7 months. That’s why all of us who played with little beads of mercury as kids didn’t drop dead or lose our marbles.

The infinitesimal amounts of mercury detected in the samples in this study are so far below any level that has ever been even remotely associated with the slightest effect on humans — even if it was absorbed in our gut — that the panic reaction and massive and costly interventions being proposed to test and label every food, or to create a mercury-free environment, in order to be safe are especially illogical.

The president of the Corn Refiners Association also told Reuters this morning that their industry hasn’t used mercury reagents mentioned in the study for years, leading her to question the information.

Bottom line evidence. Notice how this study only reported having detected mercury in HFCS, but didn’t measure the mercury level in a single person or child — they left it to our imaginations to assume that detectable levels in our foods meant dangerous levels in our bodies. There is no credible support to fear that the mere presence of mercury — in a fraction of a part per million — in HFCS, and other foods we regular eat, is dangerous.

The final reassuring proof comes from CDC tests of the actual amounts of mercury in our bodies. Since 1999, NHANES has studied mercury levels in our bodies and found that even in the most vulnerable groups of Americans, women and children, we don’t have values anywhere near actual unsafe levels.

The level used for safety regulations has an enormous built-in safety margin. To arrive at this level, they took the level where there was no observed effect at all in the most sensitive of the population with a lifetime of exposure — a level nearly ten times that found in most American women — and added another ten-fold safety cushion to that. This safety cushion is not a threshold where there is any possible actual risk to health — even though it’s used by those trying to scare us to define “high.”

Beliefs that we can only be safe by removing every trace of any substance that has ever been shown to be toxic [at high doses] from our foods, means not eating or drinking anything at all.

Science gives us better sense than that.

Part Two is here.

© 2009 Sandy Szwarc