A reader forward a recent study that suggest that corn (at least corn in a region that GMO corn may exist) may be not suitable to CFS patients.
CFS patients often have issues with excessive histamine. In my recent post on Amino Acids, histidine was found to be HIGH in CFS patients. “increases in 3-methylhistidine (P < 0.05) and tyrosine (P < 0.05) were observed”  ” The urinary excretions of histamine, N tau-methylhistamine, imidazole acetic acid, and its conjugate(s) were higher in patients with histidinemia than in controls, and these levels of excretion were correlated with the plasma histidine level. The urinary histamine levels of patients with eczema-like dermatitis were twice that of those without dermatitis.” 
So what is the problem of corn?
“Glyphosate tolerant genetically modified (GM) maize NK603 was assessed as ‘substantially equivalent’ to its isogenic counterpart by a nutrient composition analysis in order to be granted market approval.” This study may potentially apply to Glyphosate tolerant genetically modified (GM) Soy.
” Other similar biogenic amines, such as N-acetyl-cadaverine, N-acetylputrescine and putrescine were also found to be present at higher levels in NK603 in our investigation…In certain contexts some of these polyamines have been found to be protective whereas in other situations they can be a cause of toxicity. On the one hand, toxicological effects such as nausea, headaches, rashes and changes in blood pressure are provoked by the consumption of foods with high concentrations of polyamines56… Putrescine and cadaverine have been reported as potentiators of the effects of histamine, and both have been implicated in the formation of carcinogenic nitrosamines with nitrite in meat products”
From: “Mesnage, R. et al. An integrated multi-omics analysis of the NK603 Roundup-tolerant GM maize reveals metabolism disturbances caused by the transformation process. Sci. Rep. 6, 37855; doi: 10.1038/srep37855 (2016).”
Putrescine and cadaverine
If you have issues with histamines, you want to avoid foods relatively high in these substances.
- “The symptoms of histamine poisoning generally resemble the symptoms encountered with IgE-mediated food allergies (Taylor and others 1989) and usually appear shortly after the food is ingested with a duration of up to 24 h. Symptoms may be gastrointestinal (nausea, vomiting, diarrhea), circulatory (hypotension), cutaneous (rash, urticaria, edema, localized inflammation), and neurological (headache, palpitations, tingling, flushing or burning, itching). ” [FDA]
- “very large amounts of histamine could be given orally without causing adverse effects. He attributed this to the conversion of histamine to inactive N-acetylhistamine by intestinal microflora.” (So a shift in microflora could cause histamine issues).
- Sea Food was found to be high in these chemicals.
- The above link gives tables of the bacteria producing significant amounts of histamines (i.e. Proteus spp., Morganella morganii, Proteus morganii, Klebsiella spp., Enterobacter aerogenes and E. cloacae, etc)
- “no tolerable levels in foods have been established so far. The present study suggests tolerable levels in cheese, fermented sausages, fish, sauerkraut and seasonings that are based on toxicological threshold levels, occurrence of diamines in foods and food consumption in Austria.” 
General Corn and Soy products may not be suitable for CFS patients with histamine issues. I personally know someone that will have a histamine reaction to a low amount of soy in any food — she must check every label to insure that there is none.