Re: Effects of added MSG to a child's diet

 In my opinion, it is extremely unlikely that monosodium glutamate or aspartame
(the generic name for Nutrasweet) are causing problems such as Attention Deficit
Hyperactivity Disorder (ADHD or ADD).  In the case of monosodium glutamate, very 
little if any actually crosses the blood-brain barrier and gets into the brain 
in the first place.  Aspartame does cross the blood-brain barrier, and a 
controversy has been raging since its introduction about whether it can cause 
harmful effects on the brain and nervous system.  Run a search on the Web to 
see what I mean about this controversy.  But aspartame is typically 
found in diet sodas and other low-calorie products which most children do not 
eat.
 Twenty years ago is only 1978-- not really that far back in terms of food 
preparation and mass production.  I was nine years old then, and I certainly ate 
plenty of prepackaged junk food, as did all of my peers.  Doritos, Fritos, 
Twinkies, etc.-- all of these were popular in the 1970's, probably just as 
popular then as they are today.  One could perhaps argue that there has been an 
increase in MSG consumption among children, but it's by no means a case of going 
from virtually none to a whole lot in the span of two decades.
 In any case, the biggest reason for the increase in ADD is simply increased 
diagnosis.  In fact there have been some studies where researchers have looked 
at the report cards of ADD adults from back in the 1940's and 1950's.
They typically had a lot of bad grades and comments from teachers about their 
unruly behavior, but they were never diagnosed with ADD, because ADD did not 
exist at that time as a clinical concept.  Now that most of the US public, 
including parents, teachers, and pediatricians, is aware of the possibility of 
classifying a child as having ADD, the number of such children has inevitably 
grown substantially.  Trying to sort out what percentage of the increase is due 
to greater awareness and what percentage is due to some environmental factor 
such as MSG or aspartame would be a well-nigh impossible task.  One way it could 
be done would be to look cross-culturally, at societies which are similar in 
terms of economics and medicine but different in terms of eating patterns.  For 
example, the cyclamates, artificial sweeteners that are banned in the US, are 
still in use in Europe.  Perhaps there are countries where aspartame is not 
available and MSG is not used with any frequency.  If those countries could be 
shown to have lower rates of ADD, at a similar level of public awareness, then 
maybe a case could be made for a link.  But it would still only be a 
correlation, not a causal connection.  Much more sophisticated studies, most 
likely involving animal research, double-blind studies of children, and years of 
follow-up, would be necessary to make a strong argument that MSG or aspartame 
could predispose children to develop ADD.

Joe Simpson
MD/PhD Student, Neurosciences Program
 School of Medicine
St. Louis, Missouri, USA