In January 2009, the Minnesota-based Institute for Agriculture and Trade Policy (IATP) released the results of a laboratory study that detected minute traces of mercury in 17 out of 55 foods and beverages purchased from grocery stores. In a report titled “Not So Sweet,” IATP wrote that since high fructose corn syrup was “the first or second ingredient on the label” in every product its researchers tested, the sweetener “appears to be a significant additional source of mercury, one never before considered.”

Major media reported IATP’s findings, warning consumers that “High-fructose corn syrup contains mercury,” and that food made with the sweetener “may have traces of toxic metal.”

But public anxiety spurred by the IATP study is completely unfounded. The researchers’ methodology was deeply flawed. And IATP’s failure to put the tiny levels of “detected” mercury into proper perspective raises serious questions about the organization’s commitment to honest advocacy.

The IATP researchers’ study was so unscientific that it failed to include a “control” group. (They should have also tested some grocery products that did not contain any high fructose corn syrup.) It’s impossible to know whether mercury traces did indeed come from high fructose corn syrup, and the answer could blow IATP’s entire thesis out of the water.

The laboratory that tested IATP’s samples detected mercury in less than a third of them (17 out of 55). And even those levels—measured in parts per trillion—were far too small to pose any unusual risks to consumers. One part per trillion is equivalent to a single drop of water in 26 Olympic-size swimming pools.

Even clean drinking water, according to the World Health Organization, “is considered to be a minor source of exposure to mercury” at the level of 0.5 micrograms per liter, or 500 parts per trillion. IATP’s highest measured mercury level, by comparison, was 350 parts per trillion (in instant oatmeal).

In addition, the “reporting” threshold used by IATP’s chosen laboratory did not include a Minimum Reporting Limit (see glossary), a basic safeguard used to help scientists avoid reporting “false positives.”

IATP’s approach was also flawed in a more basic sense. Complaining about imagined health risks related to one square on the Periodic Table, whether it’s mercury or any other element, misses the forest for the trees. Nutrition is far more complex than the impact of any one nutrient or contaminant.

In 2003, a study conducted by scientists at Health Canada found measurable mercury levels in dozens of common foods, including baby formula, broccoli, carrots, celery, blueberries, grapes, peas, raisins, raspberries, rice, strawberries, and tomatoes. These foods are considered wholesome and healthful even though they all contain mercury in trace amounts. Mercury levels in canned mushrooms tested for that study were between 5,100 and 16,000 parts per trillion.

Based on IATP’s own questionable data, a typical consumer would have to drink 181,797 cans of sugary soda to be exposed to the same amount of mercury in a single compact fluorescent light bulb.

IATP should withdraw or update “Not So Sweet,” and news editors should be especially wary about accepting the group’s future research conclusions without assurance that basic scientific protocols are followed.