Hobsley, M

Tovey, FI

UCL Discovery

Clarification of the link between polyunsaturated fatty acids and Helicobacter pylori-associated duodenal ulcerdisease: a dietary intervention studyIt would have been interesting if Duggan et al. (1997), intheir report in your journal, had been able to take duodenalbiopsies to compare the presence and extent of duodenalgastric metaplasia between the subjects on a high- and on alow-polyunsaturated-fat diet. It would be of interest also toknow whether those subjects who had active duodenalulcers showed any endoscopic improvement as a result oftaking a high-polyunsaturated-fat diet.Duodenal gastric metaplasia is always found in associa-tion with duodenal ulceration and is a necessary prerequisitefor Helicobacter pylori colonization of the duodenum fromthe antrum. The geographical distribution of duodenalulceration, with the presence of areas of high and lowprevalence, has shown a strong relationship with staplediets (Tovey & Tunstall, 1975; Tovey, 1979, 1992, 1994;Tovey et al. 1989). In India our own studies and those ofothers showed a high prevalence of duodenal ulcer in all ofthe polished-rice-eating areas, especially in the Southand in Bangladesh, and a low prevalence in the unrefined-wheat-eating areas of the North, in particular in the Punjab.The prevalence was also low in isolated areas where certainmillets, certain pulses or ragi (Eleusine coracana) formed alarge part of the staple diet.Our experiments on animal peptic ulcer models show thatthe North Indian Punjabi diet is protective against ulcera-tion, whereas the South Indian diet is ulcerogenic (Jayarajet al. 1980, 1986, 1987). This protective activity is presentin certain foodstuffs such as unrefined wheat, soya, ragi andsome millets and lentils. The lentil Horse Gram (Dolichosbiflorus) is markedly protective. This protective activity hasbeen shown to lie in the lipid fraction of these foodstuffs.This fraction contains essential fatty acids such as linoleicacid, phospholipids and phytosterols, all of which have beenshown experimentally to enhance mucosal cytoprotection(Tarnawski et al. 1987; Lichtenberger et al. 1990; Romero& Lichtenberger, 1990).From available evidence, Helicobacter infection of theantrum seems to be equally prevalent in the high- and low-duodenal-ulcer areas of India and is not a factor in explain-ing the differences in prevalence. It is possible that thepresence of protective factors in diet may explain thesedifferences. The protective factors may enhance the resis-tance of the duodenal mucosa, enabling it to withstand acidand pepsin, and consequently the development of gastricmetaplasia. To account for changes in duodenal ulcerprevalence it may be that we ought to be looking for theeffect of diet on duodenal gastric metaplasia and not at anyeffect on the extent of Helicobacter pylori infection.ReferencesJayaraj AP, Rees KR, Tovey FI & White JS (1986) A molecularbasis of peptic ulceration due to diet. British Journal of Experi-mental Pathology 67, 149–155.Jayaraj AP, Tovey FI & Clark CG (1980) Possible dietaryprotective factors in relation to the distribution of duodenalulcer in India and Bangladesh. Gut 21, 1068–1076.Jayaraj AP, Tovey FI, Clark CG, Rees KR, White JS & Lewin MR(1987) The ulcerogenic and protective actions of rice and ricefractions in experimental peptic ulceration. Clinical Science 72,463–466.Lichtenberger LM, Romero JJ, Kao YCJ & Dial EJ (1990) Gastricprotective activity of mixtures of saturated polar and neutrallipids in rats. Gastroenterology 99, 311–326.Romero JJ & Lichtenberger LM (1990) Sterol dependence ofgastric protective activity of unsaturated phospholipids. Diges-tive Diseases and Sciences 35, 1231–1238.Tarnawski A, Hollander D & Gergely H (1987) Protection of thegastric mucosa by linoleic acid – a nutrient essential fatty acid.Clinical and Investigative Medicine 3, 132–135.Tovey FI (1979) Peptic ulcer in India and Bangladesh. (Progressreport) Gut 20, 329–347.Tovey FI (1992) Duodenal ulcer in China. Journal of Gastroenter-ology and Hepatology 7, 427–431.Tovey FI (1994) Diet and duodenal ulcer. Journal of Gastroenter-ology and Hepatology 9, 177–85.Tovey FI, Jayaraj AP, Lewin MR & Clark CG (1989) Diet: Its rolein the genesis of peptic ulceration. Digestive Diseases 7, 309–323.Tovey FI & Tunstall M (1975) Duodenal ulcer in black populationsin Africa south of the Sahara. (Progress report) Gut 16, 564–576.Frank I. ToveyMichael HobsleyDepartment of SurgeryUniversity College LondonLondon W1P 7LDUnited KingdomClarification of the link between polyunsaturated fatty acids and Helicobacter pylori-associated duodenal ulcerdisease: a dietary intervention study – reply by Duggan & SpillerWe agree that the epidemiological data linking diet andduodenal ulcer disease quoted by Tovey & Hobsley (1998)have yet to be made clear. Our experimental studies showthat very substantial amounts of PUFA in the diet do notsignificantly alter Helicobacter pylori infection in theantrum. As Tovey and Hobsley point out, this still leavesa possibility that these diets are protective because of theirimpact on duodenal metaplasia which we did not examine.116 Nutrition Discussion ForumReferenceTovey FI & Hobsley M (1998) Clarification of the link betweenpolyunsaturated fatty acids and Helicobacter pylori-associatedduodenal ulcer disease: a dietary intervention study (letter).British Journal of Nutrition 80, 116.Anne DugganRobin SpillerDivision of GastroenterologyUniversity HospitalNottingham NG7 2UHUnited Kingdomq Nutrition Society 1998117Nutrition Discussion Forum

Clarification of the link between polyunsaturated fatty acids and Helicobacter pylori-associated duodenal ulcer disease: a dietary intervention study

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Clarification of the link between polyunsaturated fatty acids and Helicobacter pylori-associated duodenal ulcer disease: a dietary intervention study

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