Child Diet and Learning Disabilities

Learning disabilities are a common problem today and seem to be on the rise. A new article in the October 2009 issue of Behavioral and Brain Functions journal examines how diet-related factors, like synthetic food dyes, mercury contamination and mineral deficiencies, are being linked to such problems.

David Wallinga, MD, director of the Food and Health Program at the Institute for Agriculture and Trade Policy and a co-author of the article, recently sat down with Organic Connections to explain some of these factors and their potential influences.

“The article reviews, I would say, three different kinds of interrelated problems,” Dr. Wallinga said. “The first is synthetic food dyes, which are largely petroleum based. Individually, there’s already evidence that these contribute to problems in children related to learning, such as lack of attention. There’s a call in the UK, for example, for food manufacturers to phase out these synthetic food dyes completely.

“The second kind of problem is just the general failure of the American diet to provide necessary nutrition. Most Americans don’t eat a healthy diet, period. And a big piece of that is they’re eating foods that don’t deliver adequate amounts of essential nutrients or minerals, like selenium or zinc—two that are mentioned a lot in the article.

“And then the third piece is environmental toxins, such as heavy metals, that end up in the diet, either through contamination or because they are intentionally put in foodstuffs.”

Dr. Wallinga pointed out that exposure to mercury—as an example of a heavy metal—is bad for the brain and can have impacts on learning and behavior. There are also crucial nutrients that help expel mercury from the body, in which a percentage of the population are deficient due to poor diets. On top of that, there are other factors. “People are not uniform in the degree to which they might be affected by this,” Dr. Wallinga explained. “There are naturally some people in the population who already are reduced or deficient in their ability to expel mercury from their bodies. There are also some people who are more sensitive to mercury. So this is a potential problem for everyone, but it’s likely to impact some people more than others.”

Interestingly, mercury contamination occurs in certain food chemicals—already potentially harmful—that end up in American diets. According to the article, mercury has been historically used to manufacture a number of food ingredients, including color additives, such as FD&C Yellow 5, FD&C Yellow 6 and high-fructose corn syrup. In an article published earlier this year in Environmental Health, scientists found detectable mercury in commercial high-fructose corn syrup samples collected by the FDA in 2005.

High-fructose corn syrup is an additive that has been widely used since the 1980s, and which, according to the article, can lead to zinc and other deficiencies in humans. There is also likely much more to be discovered. “I think that the jury is still out on what the long-term effects of high-fructose corn syrup are, especially given its prevalence in the American diet,” said Dr. Wallinga. “A huge portion of our daily calories, especially in our kids, comes from high-fructose corn syrup. And then I think, obviously it’s not necessary; we got along just fine without it for eons. So it raises in my mind this sort of precautionary argument that there are other things we can add to our foods that don’t have some of these same concerns, whether it’s mercury contamination or links to metabolic syndrome. Therefore, as a parent, I just think the precautionary approach is to try to limit high-fructose corn syrup consumption, even if it’s not made with mercury.”

Fortunately, efforts are underway at a regulatory level to eliminate some of these problems. The Center for Science in the Public Interest last year submitted a petition to the FDA to “ban the use of Yellow 5 and other food dyes, in the interim to require a warning on foods containing these dyes, to correct the information the Food and Drug Administration gives to consumers on the impact of these dyes on the behavior of some children, and to require neurotoxicity testing of new food additives and food colors.”

Regarding dyes, Dr. Wallinga remarked, “We’re in this strange situation where we have prominent food companies making one line of products without these brain-active food dyes for the UK market and another line of the same products for the American market with these brain-active food dyes in them. That just seems like a silly state of affairs.”

Congress is also currently debating an important piece of legislation called HR 2065, Mercury Pollution Reduction Act of 2009. “This act would have the US support steps to stop using outdated mercury-contaminating processes worldwide,” Dr. Wallinga said. “The US has started transitioning into other ways of making chemicals without mercury, which is good. But because we’re in a global economy—and a global food economy in particular—does that do us much good if food companies continue to buy products overseas that are still mercury contaminated? We would never know, because these products aren’t really being tested for mercury contamination. It actually needs to be a global approach, and that’s what this bill would do. It would put the US on record supporting a global phase-out of mercury being used in facilities that can lead to food contamination with mercury.”

On a more practical level, what should we tell average consumers, who might not be informed, about which types of comestibles to look out for?

“Instead of telling people what to look out for, I think it’s more effective to tell them what to look for,” Dr. Wallinga concluded. “I think they ought to be looking for whole foods without added food dyes, without a lot of processing, because, again, it’s clear that we don’t often know what’s in those processed foods or what the brain-active impacts of those additives are. Whole-food diets are more likely to meet their nutritional needs, which obviously they’re not getting through the current diet.

“Parents and consumers have a role with our policy makers too. Their voices are incredibly important for stopping the introduction of mercury into the food system and holding food manufacturers in the US to the same standard as those in the UK with respect to petroleum-based food additives and the like.”

For much more information—including a table of the amount of mercury detected in 55 brand-name foods and beverages containing high-fructose corn syrup as the first or second ingredient—visit the Institute for Agriculture and Trade Policy website at www.iatp.org.

An excellent guide to food additives can also be found at the Center for Science in the Public Interest website at www.cspinet.org/reports/chemcuisine.htm.