by Marion Nestle

Currently browsing posts about: Additives

Mar 12 2008

What’s the story on MSG?

Last week, Allison wrote: “I recently read the NYTimes article about MSG [monosodium glutamate] and although you were quoted, I’d love to hear more of your thoughts.”

This is a tough one. My files on MSG go back to 1971 when the FDA said this flavor enhancer, the sodium salt of an amino acid that forms part of virtually all proteins, was safe for everyone “except for those who are individually sensitive to the substance.” By these, it meant people who reacted to foods containing MSG with headaches, tingling, flushing or other such neurological symptoms. Because Chinese food contained a lot of MSG, the symptoms came to be known as “Chinese Restaurant Syndrome.” In the late 1970s, scientists weighed in with reports of placebo-controlled trials that showed no reaction to MSG except for the first half hour after eating it. By 1980, scientists concluded that MSG only caused problems for a small percentage of individuals who had a genetic susceptibility. Placebo-controlled trials continue to find no difference in symptoms when people consume MSG or a placebo. That is why I told the reporter that there was no clinical evidence for problems and why “I thought the issue was settled though I know a lot of people will never believe that.” I wish what I had said next had been included because I went on to explain that such studies cannot account for the very real experience of people who experience symptoms, such as those whose letters appear in today’s Times.

How to make sense of this? MSG susceptibility falls into the category of many other food sensitivities and allergies, most of which are exceedingly difficult to diagnose. The science of food sensitivities, like much of nutrition science, is difficult to do, especially when serious symptoms are relatively rare in the population (it is too expensive to do studies on a large enough sample of individuals to get meaningful results).

If you are one of those people who experiences symptoms from MSG, there is only one thing to do: avoid it. And that brings us to the need to have more informative food labels. One again, we are in the realm of food politics.

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Sep 7 2007

Food Additives and Hyperactivity–Again!

I thought we were done with food additives as a cause of hyperactivity in kids years ago, but here it comes again. A new and well controlled study in The Lancet, funded by the British Food Standards Agency (which presumably has no axe to grind), reports higher average levels of hyperactivity in young children drinking a mix of sodium benzoate (a preservative) and food colors. For why these results surprise me, take a look at the Wikipedia entry for the Feingold Diet, the additive-free diet developed decades ago to prevent hyperactivity in kids. The first Wikipedia paragraph says it all:

“The Feingold diet is a food elimination program developed by Ben F. Feingold, MD to treat hyperactivity. It eliminates a number of artificial colors and artificial flavors, aspartame, three petroleum-based preservatives, and (at least initially) certain salicylates. There has been much debate about the efficacy of this program. Some mainstream medical practitioners deny that it is of any value, while other medical practitioners, as well as many people living with ADHD and parents of children with ADHD, claim that it is effective in the management of ADHD as well as a number of other behavioral, physical and neurological conditions. The debate has continued for more than 30 years, involving not only consumers and physicians, but scientists, politicians, and the pharmaceutical and food industries.”

After this excellent beginning, the article gets so muddled that the editors warn: “The neutrality of this article is disputed.” Indeed. Until now, my reading of the science was that the more carefully the studies were done, the less benefit they showed. Even the best studies showed wide individual differences–most kids were unaffected by removing additives but a small percentage seemed to get better. This made the studies especially subject to biased interpretation.

This new study seems well done but again shows large individual differences, so expect the debates to continue. In the meantime, it’s good to remember that color additives go into processed foods to cover up flaws and make them look attractive. Kids don’t need to be eating highly processed foods. The study is another good reason to feed kids plenty of fruits, vegetables, and other minimally processed foods.

Here’s what today’s New York Times has to say about the study.