A study of 3,011 unrelated white Australians found that 14% were heterozygous carriers of an HFE mutation, 0.5% were homozygous for an HFE mutation, and only 0.25% of the study population had clinically relevant iron overload. Most patients who are homozygous for HFE mutations do not manifest clinically relevant haemochromatosis (see Genetics above). Other populations have a lower prevalence of both the genetic mutation and the clinical disease. It is the most frequent genetic disease in the U.S. with a prevalence of 1:300 in the non-Hispanic white population, It is 2-3 times most common in males.Genetics studies suggest the original haemochromatosis mutation arose in a single person, possibly of Celtic ethnicity, who lived 60–70 generations ago. At that time, when dietary iron may have been scarcer than today, the presence of the mutant allele may have provided an evolutionary advantage by maintaining higher iron levels in the blood.The distribution of the C282Y variant was noted in various countries. Non-HFE associated hemochromatosis, as Haemochromatosis type 2, Haemochromatosis type 3, Haemochromatosis type 4 and Haemochromatosis type 5, were discovered in Mediterranean countries. On the other side, Northern European ancestry is closely linked to hereditary hemochromatosis disease (HFE). In one study, over 93% of Irish patients with HFE C282Y mutation were homozygotic. The G320V mutation in the HJV gene, which produces hemojuvelin protein, is widely distributed in central Europe and Greece. Terminology
The term "haemochromatosis" is used by different sources in many different ways. It is often used to imply an association with the HFE gene.
The FASEB report reaffirmed the safety of MSG when it is consumed at usual levels by the general population, and found no evidence of any connection between MSG and any serious long-term reactions.Under 2003 U.S. Food and Drug Administration regulations, when monosodium glutamate is added to a food, it must be identified as "monosodium glutamate" in the labels ingredient list. Because glutamate is commonly found in food, primarily from protein sources, the FDA does not require foods and ingredients that contain glutamate as an inherent component to list it on the label. Examples include tomatoes, cheeses, meats, hydrolyzed protein products such as soy sauce, and autolyzed yeast extracts. These ingredients are to be declared on the label by their common or usual names. The term natural flavor is now used by the food industry when using glutamic acid. Because of lack of regulation, it is impossible to determine what percentage of natural flavor is actually glutamic acid. The food additives disodium inosinate and disodium guanylate are usually used in synergy with monosodium glutamate-containing ingredients, and provide a likely indicator of the addition of glutamate to a product. As of 2002 the National Academy of Sciences Committee on Dietary Reference Intakes had not set a NOAEL or LOAEL for glutamate. Australia and New Zealand
Standard 1.2.4 of the Australia New Zealand Food Standards Code requires the presence of monosodium glutamate as a food additive to be labeled.