About 1.5 years ago I started having these awful sensitivities to certain substances, there were lot's of them, but the main ones were MSG, aspartame and capsaicin. The symptoms that I almost invariably got (I did some experiments to confirm this) were severe insomnia, whole body itchiness, hot flushes and suicidal thoughts. Then fast forward a year and a quarter and those terrible after effects are 90% gone even after eating decent amounts of the substances mentioned. Now this is very interesting how such sensitivities can fluctuate so much. I have a few theories as to how this is possible. Just throwing one out there is that maybe a CFS crash caused my blood brain barrier to get out of whack. With the effect of those substances getting more easily to the brain where they can do damage. What mechanism there might be behind this I can only speculate. If ME/CFS is a disease originating from the cellular level, maybe the crash caused blood barrier cells to become dysfunctional / energy depleted thus making the barrier dysfunctional as well? Do you guys think this is a plausible explanation? Any other theories or comments?