Table 1.

Medically driven food prohibitions (compiled from NORD [13]).

Disease/Syndrome	Causative Food	Cause	Comment
Disaccharide intolerance	Sucrose, dextrins	Autosomal recessive trait characterized by the deficiency or absence of enzymes sucrase and isomaltase in the intestine.	Attacks characterized by bloating and diarrhea.
Favism	Broadbean (Vicia fava)	X-linked recessive trait resulting in low amounts of glucose-P-dehydrogenase. Several subtypes known.	Hemolytic anemia may result from consumption of offending foods.
Galactosemia	Galactose and lactose (dairy products)	Autosomal recessive trait with low levels of any one of three enzymes directly responsible for galactose metabolism.	High levels of galactose in the blood results in hepatomegaly, cirrhosis, and renal failure. Infant mortality is ~75%.
Gluten intolerance	Wheat, barley, gluten containing foods	Autoimmune disease	Sensitivity to storage protein (gliadin) in some grains.
Lactose intolerance	Dairy products	Inborn error of metabolism—low or no lactase enzyme in the intestine.	Lactase is required to cleave lactose (a disaccharide of galactose and glucose). Bloating and diarrhea may develop.
Ornithine transcarbamylase deficiency	Dietary nitrogen (primarily meat)	X-linked recessive disorder resulting in low production of hepatic ornithine transcarbamylase interrupting the urea cycle and leading to accumulation of ammonia.	Although usually first seen in neonates, there may be an adult onset.
			Citrullinemia is another genetic disease affecting the urea cycle.
Phenylketonuria (PKU disease)	Phenylalanine in foods	Autosomal recessive trait characterized by inadequate hepatic phenylalanine hydroxylase.	Leads to accumulation of phenylpyruvate which may accumulate in the brain and lead to seizures, mental retardation, etc. Products containing phenylalaine must be labeled.
Refractory sprue	Wheat, barley and rye	Autoimmune disorder triggered by gliadin, a gluten storage protein.	Unlike common celiac sprue, adherence to a gluten-free diet may not cause symptoms to abate.
Trimethylaminuria	Fish	Autosomal recessive resulting in low production of flavin containing monoxygenase enzyme 3 (FMO3).	Fish odor syndrome. Failure to breakdown trimethylamine, a build of which results in a fish odor.
Very long chain Acyl CoA dehydrogenase deficiency (LCAD)	Very long chain fatty acids	Autosomal recessive trait resulting from a mutation in the HADHA gene.	Prevents mitochondrial metabolism of very long chain fatty acids.