Thomas P. Bleck tpb9k at
Thu Aug 24 09:24:53 EST 1995


	I've been intrigued by your comments about aspartame, so I've
been looking into this a little more deeply.  I am still reviewing MS
epidemiology reports, but so far I haven't been able to find any
increase in either the incidence or prevalence of MS since the
introduction of aspartame.

	Since your information is anecdotal, I will mention that in
the last 20 years of taking care of MS patients, I have not seen any
change in the disease, nor have I seen anyone who thought that their
condition was induced or worsened by aspartame.  This group of
patients, including some of my most favorite ones, are very willing to
report their suspicions about events or substances that worsen or
improve their conditions.  One of my patients was convinces that an
antistatic compound sprayed onto his pants decreased that spasticity
in his legs, for example.  I expect that some of them would have
mentioned a connection to aspartame if they had noticed one.

	I want to underscore the lack of a change in the nature of MS
as a disease over this period of time.  About half of all MS patients
experience a clearly relapsing-remitting pattern, which would confound
any attempts to determine whether a given substance is helpful (e.g.,
steroids to speed recovery from an exacerbation, or beta-interferon),
harmful (e.g., gamma-interferon), or has no effect (almost everything
else that has been tried) without double-blind, randomized trials.
Patients and everyone who sees them, including their physicians, may
think that some substance has an effect, but their ability to draw a
connection between the activity of their disease and any environmental
stimulus is very limited.  Within these limits, which clearly bias
both me and my patients in favor of thinking we see a connection where
none exists, I must tell you that MS is the same disease as it was 20
years ago.  My patients' slurred speech back then couldn't have been
caused by aspartame, could it?

	As an investigator who has spent a fair amount of time looking
at ways to undo CNS toxicity due to excitatory amino acid (such as
glutamate and aspartate) and free radical mechanisms (which are
intimately tied to the excitatory amino acids in many circumstances),
I am also intrigued by your comment that apartate and phenylalanine
will cross the blood-brain barrier in the absence of other amino
acids, and thereby produce neurotoxicity.  I am quite familiar with
this literature, and am unable to find any studies which show this.
Please direct me to the source of this information (which, I hope, is
not simply someone's opinion that this could happen).

	Thank you.

Tom Bleck    (Thomas P. Bleck, M.D.)   tbleck at
Departments of Neurology, Neurosurgery, and Medicine
University of Virginia School of Medicine

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