title: Maize meal predisposes to endemic squamous cancer of the oesophagus in Africa: breakdown of esterified linoleic acid to the free form in stored meal leads to increased intragastric PGE2 production and a low-acid reflux.
abstract: Endemic cancer of the oesophagus in Africa is associated with the use of maize as the staple. In one African community endemic cancer of the oesophagus has been shown to have a strong statistical association with the consumption of foods based on maize in the meal form. A strong association with consumption of maize meal has also been shown in a region of Italy. It has been argued in the past that the association with maize consumption is due to a fortuitous association; or due to the nutritional deficiencies of maize meal; or due to fungal contamination. We argue that maize meal is a distinctly different food from whole maize, and that nutritional content as much as deficiency is responsible for predisposition of the oesophagus to carcinogenesis. An important factor is the breakdown of esterified linoleic acid to the free form in stored maize meal. This leads to excess production of prostaglandin E2 in the stomach. The excess Prostaglandin E2 causes a low-acid duodenogastro-oesophageal reflux, which predisposes to carcinogenesis. Supporting evidence is available that the steps of this mechanism occur in endemic areas, and that they are associated with the carcinogenic process. Health measures including poverty alleviation, health education, and monitoring and control of maize meal storage and content may be required to reduce the incidence of this disease in Africa.
authors.affiliation: Department of Surgery, Gloucestershire Royal Hospital, Gloucester GL1 3NN, England, United Kingdom, and Department of Physiology, Faculty of Health Sciences, Walter Sisulu University, Mthatha, South Africa. alastair.sammon@doctors.org.uk
authors.forename: A M
authors.initials: AM
authors.lastname: Sammon
authors.forename: J E
authors.initials: JE
authors.lastname: Iputo
mesh_terms: D000349:Africa / Q000453:epidemiology; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D003314:Corn Oil / Q000737:chemistry; D004032:Diet / Q000009:adverse effects*; D015232:Dinoprostone / Q000096:biosynthesis*; D004198:Disease Susceptibility; D019353:Endemic Diseases; D004938:Esophageal Neoplasms / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D005230:Fatty Acids, Nonesterified / Q000032:analysis; D005764:Gastroesophageal Reflux / Q000150:complications* / Q000453:epidemiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015994:Incidence; D019787:Linoleic Acid / Q000032:analysis / Q000378:metabolism*; D008954:Models, Biological; D003313:Zea mays / Q000737:chemistry / Q000378:metabolism*
chemical_list: D005230:Fatty Acids, Nonesterified; D003314:Corn Oil; D019787:Linoleic Acid; D015232:Dinoprostone