1287
Occasional
Survey
hyperlipidaemia3 gave fresh impetus to research into dietary management and dietary fibre. CARBOHYDRATE METABOLISM
DIETARY FIBRE, DIABETES, AND HYPERLIPIDÆMIA
Progress and Prospects DAVID
J. A. JENKINS
University Laboratory of Physiology, Oxford; Gastroenterology Department, Central Middlesex Hospital, London NW10
When diabetes and cardiovascular disfirst classed as possible fibredeficiency diseases, laboratory and clinical evidence was lacking. Subsequent studies indicated that the gums and viscous types of fibre (e.g., guar and pectin) are more effective than other fibres in slowing carbohydrate absorption and hence in reducing the postprandial rise in blood glucose and serum insulin. This effect has longer term metabolic consequences. In addition, gums and viscous fibres reduce serum cholesterol, possibly by mechanisms other than simply increasing bile-salt loss. If these potential therapeutic effects of fibre are to be exploited, palatable formulations must be developed. The effect of fibre in whole foods should also be determined.
Summary
ease were
INTRODUCTION
IN the early 1970s, epidemiological observations sugthat diabetes, hyperlipidaemia, and coronary heart-disease might be related to deficient intake of dietary fibre (unabsorbable plant carbohydrates and lignin).’ There was concern that not only was less highfibre food being consumed in the West than previously, but also that food processing had greatly reduced the concentration of fibre in various foods. In the beginning, direct laboratory evidence was lacking. However, the continuing debate on effectiveness and possible adverse effects of conventional drug therapy in diabetes2 and
gested
MI. Diabetes mellitus. Oxford: Blackwell Scientific Publications, 1978. 9. Cassar J, Gordon H, Dixon HG, Cummins M, Joplin GR. Simplified management of pregnancy complicated by diabetes. Br J Obstet Gynœcol 8.
Drury
1978, 85: 585-91. 10. Guillozet N. Drug risks in pregnancy revisited. J Fam Pract 1977; 4: 1043-51. 11. Editorial. Screening for congenital hypothyroidism. Lancet 1979; ii: 678-79. 12. Hanson JW. Alcohol and the fetus. Br J Hosp Med 1977; 18: 126-30. 13. Perlmutter JP. Heroin addiction and pregnancy. Obstet Gynecol Surv 1974; 29: 439-46. 14. Pirani BBK. Smoking during pregnancy. Obstet Gynecol Surv 1978; 33: 1-13. 15. MacVicar J, Chordia SKS. Premature rupture of membranes before 38 weeks of pregnancy. Br J Clin Pract 1978; 32: 249-52. 16. Eggers TR, Doyle LW, Pepperell RJ. Premature rupture of the membranes. Med J Aust 1978; i: 209-13. 17. Butler NR, Bonham DG. Perinatal mortality. Edinburgh: Livingstone, 1963. 18. Claireaux A. Stillbirths and first week deaths. In: Chamberlain R, Chamberlain G, Howlett B, Claireaux A. eds. British births 1970, vol 1: the first week of life. London: William Heinemann Medical Books, 1975: 235-53. 19. Franciosi RA, Knostman JD, Zimmerman RA. Group B streptococcal neonatal and infant infections. J Pediat 1973; 82: 707-18. 20. Editorial. Group B streptococci in the newborn. Lancet 1977; i: 520-21. 21. Nagington J, Wreghitt TG, Gandy G, Roberton NRC, Berry PJ. Fatal echovirus 11 infections in outbreak in special care baby unit. Lancet 1978; ii: 725-28.
Test Meal Studies
apples and potatoes produced a lower postprandial glucose response than equivalent refined carbohydrate loads.4 Whole apples also gave a smaller rise in serum insulin than apple puree, produced by the disruption of the fibre architecture,5 while several unabsorbable materials including guar, tragacanth, pectin, methylcellulose, wheat bran, and cholestyramine when added to drinks containing glucose or glucose syrup all produced some reduction in the blood-glucose response. The most viscous materials, guar and tragacanth, proWhole
duced the greatest reductions.6 Since insulin concentrations were reduced, they could not have been responsible for this effect. Indeed, incorporation of 16 g guar and 10 g pectin into breakfasts containing 106 g of absorbable carbohydrate, reduced the postprandial glycsemia in normal volunteers8 and insulin-dependent diabetics.9 Clinical Studies
Early in the investigations of dietary fibre, Anderson’s metabolically controlled hospital studies emphasised the potential importance of high-fibre diets. Feeding diabetics high-carbohydrate (70%), high-fibre (60 g) diets consisting mostly of unprocessed cereals and vegetables, allowed insulin requirements to be reduced considerably ; insulin could be stopped altogether in many of the patients originally on less than 30 U/day.lO Better control of the diabetes was achieved, together with reductions in both serum cholesterol and triglyceride. These gains were maintained after discharge from hospital. Strict adherence
to a
diet of uncooked foods rich in
carbohydrate and fibre also allowed patients who had been on high insulin doses to be maintained without insulin." The validity of such studies has been criticised because both fibre and carbohydrate intakes were increased simultaneously. However, addition of guar12 or
22. Davies DP, Hughes CA, MacVicar J, Hawkes P, Mair HJ. Echovirus-11 infection in a special care baby unit. Lancet 1979; i: 96. 23. Beem MO, Saxon E, Tipple MA. Treatment of chlamydial pneumonia of infancy. Pediatrics 1979; 63: 198-203. 24. Tipple MA, Beem MO, Saxon EM. Clinical characteristics of the afebrile pneumonia associated with Chlamydia trachomatis infection in infants less than 6 months of age. Pediatrics 1979; 63: 192-97. 25. Chiswick ML, James DK. Kielland’s forceps: association with neonatal morbidity and mortality. Br Med J 1979; i: 7-9. 26. Karp LE, Doney JR, McCarthy T, Meis PJ, Hall M. The premature breech: trial of labour or caesarean section. Obstet Gynecol 1979; 53: 88-92. 27. De Crespigny LJC, Pepperell RJ. Perinatal mortality and morbidity in breech presentation. Obstet Gynecol 1979; 53: 141-45. 28. Ahuja GL, Willoughby MLN, Kerr MM, Hutchison JH. Massive subaponeurotic hæmorrhage in infants born by vacuum extraction. Br Med J 1979; ii: 743-45. 29. Graham-Pole JR, Barr W, Willoughby MLN. Continuous-flow exchange plasmapheresis in severe rhesus iso-immunisation. Lancet 1974; i: 1051. 30. Clarke C, Whitfield AGW. Deaths from rhesus hæmolytic disease in England and Wales in 1977: accuracy of record and assessment of anti-D prophylaxis. Br Med J 1979, i: 1665-69. 31. Bowman JM, Chown B, Lewis M, Pollock JM. Rhesus iso-immunisation during pregnancy: antenatal prophylaxis. Can Med Assoc J 1978; 118: 623-30. 32. Willoughby MLN. Anæmias in the neonatal period, 1. rhesus disease (rhesus iso-immunisation) In: Pædiatric hæmatology. Edinburgh: Churchill Livingstone, 1977: 163-79.
1288 to hospital metabolic diets also improved diabetic control, reduced 24 h urinary glucose loss, and
cellulose fibre13 lowered
pre-meal glucose concentrations throughout the
day. Possible Mechanisms
effects.-Breath hydrogen studies8 and the excretion pattern of both xylose6 and paracetamol’4 indicate that the improvement in glucose tolerance produced by consumption of viscous fibres is due to slower absorption of carbohydrate rather than malabsorption. Guar test-meal studies on man and rats suggest that this slow absorption is produced by slower gastric emptying14,15 and slower small-intestinal absorption.16 Intimate mixing, allowing physical interaction between food and fibre, seems important in converting the carbohydrate to what might be termed a slow-release or "lente" form. Purified fibre preparations sprinkled on top of food 17 or taken with the non-carbohydrate portion of the diet17,18 have been ineffective in reducing the blood-glucose rise. In natural fibre-rich foods such as seeds, fibre in the outer coats (as in cereals) or distributed more evenly throughout the seed (as in beans) will also act as a barrier which slows enzymic attack and small-intestinal absorption. Other factors may be involved in addition to the depression of the enteroinsular response after fibrerich meals.19 Intravenous glucose tolerance was improved after fibre intake by mouth even though there was no change in insulin or gastrointestinal peptide conAcute
centrations.2O
Long-term effects.-Insulin requirement and urinary glucose output fell progressively in diabetic patients taking fibre for 2-12 weeks. 10,12,21,22 This could be due to increased insulin production, increased sensitivity to endogenous or injected insulin, or alterations in gut morphology, such as reduction in villus length, favouring slower glucose absorption. There is no evidence for increased production of endogenous insulin, nor are there any studies of small-intestinal structure. Increased sensitivity to insulin may occur and be related to other endocrine or metabolic changes. Reduced 24 h urinary 3-hydroxybutyrate (3-OHB) outputs were found in diabetics on guar-supplemented diets23 while, in normal people, addition of fibre to one glucose load resulted in lower levels of 3-OHB and free fatty acids (FFA) after 4 h and improved tolerance in response to a second glucose load.24 The apparently progressive effect of dietary fibre may, therefore, depend on sustained suppression of free fatty acid release secondary to more prolonged absorption of carbohydrate. One meal may influence the next and metabolic alterations may carry over to each successive day. HYPERLIPIDaeMIA AND FIBRE
Hypolipidaemic Effect of Fibre-supplemented Diets in Normal Subjects Fibre supplements including wheat bran;25,26 fibre extracted from carrots,26 cabbage,26 and apple ;26 bagasse (sugar cane fibre) ;27 cellulose;28 lignin;29,30 psylium husk (’Metamucil’);31 citrus pectin;26,32-37 and guar gum26,34.37 have been given at doses of 5 to 100 g/day. Only the vis-
materials, metamucil, pectin, and guar, consistently lowered total serum cholesterol by 4-16% at doses of 6 to 36 g/day. Neither high density lipoprotein (HDL) cholesterol nor serum triglyceride was lowered. Particulate fibres (e.g., wheat bran) were generally inefcous
fective.25,26 In the few studies with unprocessed high-fibre foods, chick-pea supplements reduced serum cholesterol when taken for over 20 weeks,38 as did dietary supplementation with 100 g brown beans daily39 or substitution of 140 g rolled oats in place of bread .40 However, in only one 7-day experiment where subjects took either a liquid formula diet or a high-starch, high-fibre diet (baked beans, rice, and wholemeal bread) was a fall in triglyceride seen in addition to a cholesterol reduction.4’ Clinical Studies
The use of dietary fibre in hyperlipidaemia has been little investigated. Type-ii hyperlipidmmic patients taking 15-40 g/day guar42,43 or pectin 44 over 2-8 weeks showed lower total serum cholesterol levels. An initial report of a hypocholesterolaemic action of lignin 29 in type-n hyperlipidxmia is now dispUted.3O The falls occurred in the low-density lipoprotein fraction and may therefore be therapeutically useful in reducing the risk of cardiovascular disease. Although purified fibre supplements have not lowered raised triglyceride concentrations, increasing the carbohydrate intake from 40 to 70% with unprocessed high-fibre foods significantly lowered both serum triglyceride and cholesterol concentrations in hypertriglyceridsemic diabetic patients.2’ The replacement of sugar by starch may have been important,45 nevertheless the use of natural highfibre diets warrants further attention. Mechanism
ofaction
The action of fibre in lowering serum cholesterol was originally thought to be similar to that of cholestyramine-i.e., that fibre bound bile salts in the small intestine and prevented their reabsorption. Similarly micelle and chylomicron formation, together with absorption of dietary cholesterol, would also be reduced. Thus when 12 g cholestyramine was added to a fatty test meal,46
postprandial chylomicronsemia was markedly depressed. Unexpectedly, addition of similar amounts of pectin or guar enhanced the postprandial chylomicronaemia.47 Also, guar increased the faecal bile-salt output by only 70%, compared with much larger losses induced by cholestyramine, while the 30% increase in output with pecgreater than with wheat bran, which did not lower serum cholesterol. 48 Thus binding or sequestration of bile salts to increase faecal loss cannot be the full explanation for the hypocholesterolaemic properties of certain dietary fibres.45 Increased neutral steroid loss may be a factor. In addition, by increasing the chylomicronoemia, less dietary fatty acid is available to be taken up directly by the portal vein for hepatic cholesterol synthesis.4’ Decreased postprandial insulin and blood glucose rises may also reduce the stimulus to hepatic cholesterol synthesis. 1,8,1,19 Alterations in colonic metabolism of bile acids which are reabsorbed and other substances produced during degradation of dietary fibre-e.g., methanol produced from
tin
was no
even
1289
high methoxy pectins-may suppress hepatic cholesterol synthesis. ADVERSE EFFECTS
There is
potential mineral and trace eleCereal fibre deficiency. may reduce blood levels of calcium49 and iron,5O and unleavened bread may be responsible for zinc deficiency seen in Iran.5l Cellulose52 also increases calcium losses. Fibre from many sources may bind calcium in vitro.53 However, in vivo, much of this calcium will be made available for colonic absorption as the fibre is degraded. Diabetic patients on over 20 g guar/day for 6 months had no changes in serum levels of calcium, zinc, or copper, but further study of other fibres is needed. 54 Flatulence and loose stools are two major symptoms associated with administration of purified fibre supplements. Responses vary greatly and probably relate to different dietary preference and an individual’s colonic flora. In some, symptoms gradually diminish, while in others symptoms may increase with time. concern over
ment
FUTURE DEVELOPMENTS
Incorporating viscous fibre supplements into foods is difficult. The development of a guar crispbread12.43 and a slow-gelling granulate has allowed the longer-term effects of purified fibre supplements to be explored. Further palatable products are required to facilitate good compliance and allow therapeutic potential to be fully evaluated. The search for useful naturally occurring high-fibre foods and knowledge of the background diet most suited to fibre supplementation is equally important. Initial studies suggest that, in diabetics, guar supplementation is more effective at higher levels of carbohydrate intake. 55 This may also be true for other forms of fibre. Other plant substances now refined out of the Western diet, including enzyme inhibitors, lectins, and saponins, may also lower serum cholesterol or flatten the postprandial glycaemic response by their action within the gut. The combination of two such substances, a fibre, guar, and an enzyme inhibitor, acarbose, has successfully reduced postprandial glycaemia in normal individuals.56 Thus combined intraluminal physical and chemical approaches, which reduce the rate of starch digestion and carbohydrate absorption, may help in the creation of lente carbohydrate for use in diabetic therapy. Many future therapeutic gains may come from combination of substances with different modes of action which have been eliminated from the modern Western diet. I thank Sir Francis Avery Jones, Dr E. N. Rowlands, and Prof. Richard Doll for much help and encouragement. D.J.A.J. was in receipt of funds from the British Diabetic Association and the Medical Research Council.
4.
Cong Ser 1971, 231: 325. 5. Haber GB, Heaton KW, Murphy D. Depletion and disruption of dietary fibre: effects on satiety, plasma glucose, and serum insulin. Lancet 1977; ii: 679-82. 6. Jenkins DJA, Wolever TMS, Leeds AR, et al. Dietary fibres, fibre analogues and glucose tolerance: importance of viscosity. Br Med J 1978; i: 1392-94. 7. Jeffrys DB. The effect of dietary fibre on the response to orally administed glucose. Proc Nutr Soc 1973; 33: 11A. 8. Jenkins DJA, Leeds AR, Gassull MA, Cochet B, Alberti KGMM. Decrease in post-prandial insulin and glucose concentrations by guar and pectin. Ann Intern Med 1977; 86: 20-23. 9. Jenkins DJA, Leeds AR, Gassull MA, et al. Unabsorbable carbohydrates and diabetes: decreased post-prandial hyperglycæmia. Lancet 1976; ii: 172-74. 10. Kiehm TG, Anderson JW, Ward K. Beneficial effects of a high carbohydrate, high fiber diet in hyperglycemic men. Am J Clin Nutr 1976; 29: 895-99. 11. Douglas JM. Raw diet and insulin requirements. Ann Intern Med 1975; 82: 61. 12. Jenkins DJA, Wolever TMS, Nineham R, et al. Guar crispbread in the diabetic diet. Br Med J 1978; ii: 1744-46. 13. Miranda PM, Horwitz DL. High fibre diets in the treatment of diabetes mellitus. Ann Intern Med 1978; 88: 482-86. 14. Holt S, Heading RC, Carter DC, Prescott LF, Tothill P. Effect of gel fibre on gastric emptying and absorption of glucose and paracetamol. Lancet 1979; i: 636-39. 15. Leeds AR, Bolster NR, Andrews R, Truswell AS. Meal viscosity, gastric emptying and glucose absorption in the rat. Proc Nutr Soc 1979; 38: 44A. 16. Caspary W. Effect of dietary fiber on absorption and motility. In: Creutzfeldt
W, Schöffling K,eds.The entero-insularaxis,satellitesymposium totheXth International Diabetes Federation Meeting. Göttingen. 1979: (in press). 17. Williams DRR, James WPT. Fibre and diabetes. Lancet 1979; i: 271-72. 18. Jenkins DJA, Nineham R, Craddock C, et al. Fibre and diabetes. Lancet 1979; i: 434. 19. Morgan LM, Goulder TJ, Tsioladis D, Marks V, Alberti KGMM. The effect of unabsorbable carbohydrate on gut hormones: modification of postprandial GIP secretion by guar. Diabetologia 1979 (in press). 20. Jenkins DJA. Influence of fibre and guar-supplemented food on insulin secretion and glucose tolerance. In: Creutzfeldt W, Schöffling K, eds. The Entero-insular Axis. 1979 (in press). 21. Anderson JW, Ward K. Long term effects of high carbohydrate high fibre diets on glucose and lipid metabolism: a preliminary report on patients with diabetes. Diabetes Care 1978; 1: 77-82.
Jenkins DJA, Wolever TMS, Nineham R, Bacon S, Smith R, Hockaday TDR. Dietary fibre and diabetic therapy: a progressive effect with time. In: Camerini-Davalos RA, ed. Treatment of early diabetes. New York: Plenum Press, 1979: 275-79. 23. Jenkins DJA, Wolever TMS, Nineham R, et al. Dietary fibre and ketone bodies: reduced urinary 3OHB excretion in diabetics on guar. Br Med J (in press). 24. Jenkins DJA, Nineham R, Wolever TMS, et al. Effect of eating guar and glucose on subsequent glucose tolerance. Clin Sci 1979; 57: 26P. 25. Truswell AS, Kay RM. Bran and blood lipids. Lancet 1976; i: 367. 26. Jenkins DJA, Reynolds D, Leeds AR, Waller AL, Cummings JH. Hypocholesterolemic action of dietary fiber unrelated to fæcal bulking effect. Am J Clin Nutr (in press). 27. Walters RL, McLean Baird I, Davies PS, et al. Effects of two types of dietary fibre on faecal steroid and lipid excretion. Br Med J 1975; ii: 536. 28. Shurpalekar KS, Doraiswamy TR, Sundaravalli OE, Rao MN. Effect of inclusion of cellulose in an "atherogenic" diet on the blood lipids of children. Nature 1971; 232: 554. 29. Thiffault C, Bélanger M, Pouliot M. Traitement de l’hyperlipoprotéinémie essentielle de type II par un nouvel agent therapeutique, la celluline. Canad Med Ass J 1970; 103: 165. 30. Lindner P, Möller B. Lignin: a cholesterol lowering agent? Lancet 1973; ii: 22.
1259. 31. Forman DT, Garvin JE, Forestner JE, Taylor CB. Increased excretion of fecal bile acids by an oral hydrophilic colloid. Proc Soc Exp Biol Med
1968; 127: 1060. 32. 33. 34.
35.
36. REFERENCES
37. 1. Trowell HC. Dietary
fibre, ischæmic heart disease and diabetes mellitus. Proc Nutr Soc 1973; 32: 151. 2. University Diabetic Group Diabetes Program. A study of the effect of hypoglycemic agents on vascular complications in patients with adult-onset diabetes. II Mortality results. Diabetes 1970: 19 (suppl.): 789-815. 3. Report from the Committee of Principal Investigators. A co-operative trial in the primary prevention of ischæmic heart disease using clofibrate. Br Heart J 1978; 40: 1067-1118.
GD. Frequency of diabetes with special respect to diet. In: Rodriguez RR, Vallance-Owen J, eds. Diabetes, Proceedings of 7th Congress of the International Diabetes Federation. Amsterdam: Excerpta Medica, Int
Campbell
38. 39. 40.
Fiber and pectin in the diet and serum cholesterol concentration in man. Proc Soc Exp Biol Med 1061; 106: 555. Palmer GH, Dixon DG. Effect of pectin on serum cholesterol levels. Am J Clin Nutr 1966; 18: 437. Jenkins DJA, Leeds AR, Newton C, Cummings JH. Effect of pectin, guar gum and wheat fibre on serum cholesterol. Lancet 1975; i: 1116. Durrington PN, Manning AP, Boulton CH, Hartog M. Effect of pectin on serum lipids and lipoproteins, whole gut transit-time and stool weight. Lancet 1976; ii: 394. Kay RM, Truswell AS. Effects of citrus pectin on blood lipids and fecal steroid excretion in man. Am J Clin Nutr 1977; 30: 171. Fahrenback MJ, Riccardi BA, Saunders JL, Lowrie IN, Heider JG. Comparative effects of guar gum and pectin on human cholesterol levels. Circulation 1965; 31/32 (suppl. 2): 1141. Mather KS, Khan MA, Sharma RD. Hypocholesterolæmic effect of Bengal gram: a long-term study in man. Br Med J 1968; i: 30. Luyken R, Pikaar NA, Polman H, Schippers F. The influence of legumes on the serum cholesterol level. Voeding 1962; 23: 447. De Groot AP, Luyken R, Pikaar NA. Cholesterol-lowering effect of rolled oats. Lancet 1963; ii: 303.
Keys A, Grande F, Anderson JT.
1290
authority would have, by nomination, a consultant, a general practitioner, a nurse, a university representative, and someone from the trade union movement, but disauthorities. Each
National Health Service DISTRICT HEALTH AUTHORITIES THE report of the
Royal Commission on the National which was published five months ago, Health Service, contained more than a hundred recommendations. In its first reaction’ to the report the Government concentrates on only one of them. Many issues are "being studied by the Health Departments through the ordinary machinery". Some possibilities mentioned by the Royal Commission are rejected: regional health authorities are not to be made accountable to Parliament; the N.H.S. will not be handed over to local government; there is to be no additional inquiry into the London health services ; health authorities are not to have chief executives; family practitioner committees are let out of the condemned cell. The only Royal Commission proposal seized on with any enthusiasm is the abolition of the area health authority. In a foreword to the consultative paper, Mr Patrick Jenkin, Secretary of State for Social Services, and Mr Nicholas Edwards, Secretary of State for Wales, say: approach stems from a profound belief that the needs of patients must be paramount. Whatever structure and management arrangements are devised must be responsive to those needs. The closer decisions are taken to the local community and to those who work directly with patients, the more likely it is that patients’ needs will be their prime objective." District health authorities.-With regional health authorities staying as they are, for the time being at least, only one authority would remain in the N.H.S. in England, and this would be at district level serving populations in the range 200 000 to 500 000. Some districts and areas (notably singledistrict ones) would fit the bill already but most multi-district areas will need restructuring, wherever possible along the lines of existing district boundaries. Social geography (e.g., not cutting through established community identities), hospital catch"Our
scale of facilities, and links with local government are the factors to be taken into account when restructuring is discussed. Teaching districts would be too small to meet the requirements of medical schools, so universities would be asked to forge links with more than one of the new authorities. The new authorities would be smaller in membership than the present area ones, and might have twenty members plus a chairman. Local authority representation would be reduced from a third (in A.H.A.s) to about one fifth in the new district ment areas,
trict health staff would not have the right of employee representation. The chairman would be nominated by the Secretary of State and the balance of members by the R.H.A.
Timing.-After the consultation process, the details would be handed over to R.H.A.s which would have until the end of 1983 to implement the structural changes needed. Management arrangements would take even longer since nothing could be done in new districts until they had been set up. Cost.-When the transitional costs (unspecified) have been the proposed changes "together with the general drive in the NHS for greater efficiency" should permit a reduction in management costs of up to 10%. From April 1, 1980, health authorities will be set new objectives for savings on the management side of the N.H.S.
met
Regional health authorities.-These will be responsible, after full consultation, for making proposals for the restructuring of areas. They will also, for the longer term, retain responsibilities for financial control and for coordinating strategic plans. Planning procedures should be simplified to make regional plans more sensitive to district needs. The regions will be expected to leave operational matters primarily to be settled by district health authorities. Family practitioner committees.-These should remain but, where appropriate, one F.P.C. may cover more than one district. Professional advice.-The simplification of the professional advisory committee structure is being looked into by a working-party under the Chief Medical Officer. Community health councils.-The Government is clearly tempted to do away with these councils-next year they will cost C4 million and the new authority members should be less remote from local services than A.H.A. members are-but it limits itself to an invitation to comment on whether C.H.C.s should be retained under the new district structure.
Consultants’ contracts.-There is a strong authorities to hold consultant contracts.
case
for district
Area services.-The changes have implications for ambulance and scientific services and the like, and R.H.A.s would have to approve splitting or sharing arrangements. Comments should be sent, by April 30, 1980, to Regional Liaison Division 5A, D.H.S.S., Euston Tower, 286 Euston Road, London NW3DN, or to the Welsh Office in Cardiff. 1.
Department of Health and Social Security and Welsh Office. Patients First: consultative paper on the structure and management of the National Health Service in England and Wales. H.M. Stationery Office. 1. l.
48.
Jenkins DJA, Leeds AR, Gassull MA, Houston H, Goff DV, Hill MJ. The cholesterol lowering properties of guar and pectin. Clin Sci Mol Med 1976; 51: 8P.
41. Albrink
MJ, Newman T, Davidson PC. Lipid-lowering effect of a very high carbohydrate high fiber diet. Diabetes 1976; 25 (suppl): 324A. 42. Jenkins DJA, Leeds AR, Slavin B, Mann J, Jepson EM. Dietary fibre and blood lipids: reduction of serum cholesterol in type II hyperlipidæmia by guar gum. Am J Clin Nutr 1979; 32: 16-18. 43. Jenkins DJA, Reynolds D, Slavin B, Leeds AR, Jenkins AL, Jepson EM. Dietary fiber and blood lipids: treatment of hypercholesterolemia with guar crispbread. Am J Clin Nutr 1979 (in press). 44. Miettinen TA, Tarpila S. Effect of pectin on serum cholesterol, fecal bile acids and biliary lipids in normolipidemic and hyperlipidemic individuals. Clin Chim Acta 1977; 79: 471-77. 45. Kritchevsky D. Fiber, lipids and atherosclerosis. Am J Clin Nutr 1978; 31: 565-74. 46. Barnard DL, Heaton KW. Bile acids and vitamin A absorption in man: the effects of two bile acid binding agents, cholestyramine and lignin. Gut 47.
1973; 14: 316-18. Jenkins DJA. The action of dietary fibre in lowering fasting
serum cholesterol and reducing postprandial glycæmia: gastrointestinal mechanisms. In: Carlson LA, et al. eds. International Conference on Atherosclerosis. New York, Raven Press 1978: 173-82.
49. Heaton KW, Pomare EW. Effect of bran on blood lipids and calcium. Lancet 1974; i: 49. 50. Jenkins DJA, Hill MS, Cummings JH. Effect of wheat fiber on blood lipids, fecal steroid excretion and serum iron. Am Clin Nutr 1975; 28: 1408-11. 51. Reinhold JG, Parsa A, Karimian N, Hammide JW, Ismail-Beigi F. Decreased absorption of calcium, magnesium, zinc, and phosphorus by humans due to increased fibre and phosphorus consumption as wheat bread. J Nutr
1976; 106: 493. 52. Pak CW, Delea CS, Bartter FC. Treatment of recurrent nephrolithiasis with cellulose phosphate. N Engl J Med 1974; 290: 175. 53. James WPT, Branch WJ, Southgate DAT. Calcium binding by dietary fibre. Lancet 1978; i: 638-39. 54. Jenkins DJA, Reynolds D, Wolever TMS, Nineham R, Taylor, RH, Hockaday TDR. Diabetic control, lipids, and trace elements after six months on guar. Clin Sci 1979 (in press). 55. Jenkins DJA, Wolever TMS, Bacon S, et al. Diabetic diets: high carbohydrate combined with high fiber. Amer J Clin Nutr (in press). 56. Jenkins DJA, Taylor RH, Nineham R, et al. Combined use of guar and acarbose in reduction of postprandial glycæmia. Lancet 1979; ii: 924.
Occasional
Survey
hyperlipidaemia3 gave fresh impetus to research into dietary management and dietary fibre. CARBOHYDRATE METABOLISM
DIETARY FIBRE, DIABETES, AND HYPERLIPIDÆMIA
Progress and Prospects DAVID
J. A. JENKINS
University Laboratory of Physiology, Oxford; Gastroenterology Department, Central Middlesex Hospital, London NW10
When diabetes and cardiovascular disfirst classed as possible fibredeficiency diseases, laboratory and clinical evidence was lacking. Subsequent studies indicated that the gums and viscous types of fibre (e.g., guar and pectin) are more effective than other fibres in slowing carbohydrate absorption and hence in reducing the postprandial rise in blood glucose and serum insulin. This effect has longer term metabolic consequences. In addition, gums and viscous fibres reduce serum cholesterol, possibly by mechanisms other than simply increasing bile-salt loss. If these potential therapeutic effects of fibre are to be exploited, palatable formulations must be developed. The effect of fibre in whole foods should also be determined.
Summary
ease were
INTRODUCTION
IN the early 1970s, epidemiological observations sugthat diabetes, hyperlipidaemia, and coronary heart-disease might be related to deficient intake of dietary fibre (unabsorbable plant carbohydrates and lignin).’ There was concern that not only was less highfibre food being consumed in the West than previously, but also that food processing had greatly reduced the concentration of fibre in various foods. In the beginning, direct laboratory evidence was lacking. However, the continuing debate on effectiveness and possible adverse effects of conventional drug therapy in diabetes2 and
gested
MI. Diabetes mellitus. Oxford: Blackwell Scientific Publications, 1978. 9. Cassar J, Gordon H, Dixon HG, Cummins M, Joplin GR. Simplified management of pregnancy complicated by diabetes. Br J Obstet Gynœcol 8.
Drury
1978, 85: 585-91. 10. Guillozet N. Drug risks in pregnancy revisited. J Fam Pract 1977; 4: 1043-51. 11. Editorial. Screening for congenital hypothyroidism. Lancet 1979; ii: 678-79. 12. Hanson JW. Alcohol and the fetus. Br J Hosp Med 1977; 18: 126-30. 13. Perlmutter JP. Heroin addiction and pregnancy. Obstet Gynecol Surv 1974; 29: 439-46. 14. Pirani BBK. Smoking during pregnancy. Obstet Gynecol Surv 1978; 33: 1-13. 15. MacVicar J, Chordia SKS. Premature rupture of membranes before 38 weeks of pregnancy. Br J Clin Pract 1978; 32: 249-52. 16. Eggers TR, Doyle LW, Pepperell RJ. Premature rupture of the membranes. Med J Aust 1978; i: 209-13. 17. Butler NR, Bonham DG. Perinatal mortality. Edinburgh: Livingstone, 1963. 18. Claireaux A. Stillbirths and first week deaths. In: Chamberlain R, Chamberlain G, Howlett B, Claireaux A. eds. British births 1970, vol 1: the first week of life. London: William Heinemann Medical Books, 1975: 235-53. 19. Franciosi RA, Knostman JD, Zimmerman RA. Group B streptococcal neonatal and infant infections. J Pediat 1973; 82: 707-18. 20. Editorial. Group B streptococci in the newborn. Lancet 1977; i: 520-21. 21. Nagington J, Wreghitt TG, Gandy G, Roberton NRC, Berry PJ. Fatal echovirus 11 infections in outbreak in special care baby unit. Lancet 1978; ii: 725-28.
Test Meal Studies
apples and potatoes produced a lower postprandial glucose response than equivalent refined carbohydrate loads.4 Whole apples also gave a smaller rise in serum insulin than apple puree, produced by the disruption of the fibre architecture,5 while several unabsorbable materials including guar, tragacanth, pectin, methylcellulose, wheat bran, and cholestyramine when added to drinks containing glucose or glucose syrup all produced some reduction in the blood-glucose response. The most viscous materials, guar and tragacanth, proWhole
duced the greatest reductions.6 Since insulin concentrations were reduced, they could not have been responsible for this effect. Indeed, incorporation of 16 g guar and 10 g pectin into breakfasts containing 106 g of absorbable carbohydrate, reduced the postprandial glycsemia in normal volunteers8 and insulin-dependent diabetics.9 Clinical Studies
Early in the investigations of dietary fibre, Anderson’s metabolically controlled hospital studies emphasised the potential importance of high-fibre diets. Feeding diabetics high-carbohydrate (70%), high-fibre (60 g) diets consisting mostly of unprocessed cereals and vegetables, allowed insulin requirements to be reduced considerably ; insulin could be stopped altogether in many of the patients originally on less than 30 U/day.lO Better control of the diabetes was achieved, together with reductions in both serum cholesterol and triglyceride. These gains were maintained after discharge from hospital. Strict adherence
to a
diet of uncooked foods rich in
carbohydrate and fibre also allowed patients who had been on high insulin doses to be maintained without insulin." The validity of such studies has been criticised because both fibre and carbohydrate intakes were increased simultaneously. However, addition of guar12 or
22. Davies DP, Hughes CA, MacVicar J, Hawkes P, Mair HJ. Echovirus-11 infection in a special care baby unit. Lancet 1979; i: 96. 23. Beem MO, Saxon E, Tipple MA. Treatment of chlamydial pneumonia of infancy. Pediatrics 1979; 63: 198-203. 24. Tipple MA, Beem MO, Saxon EM. Clinical characteristics of the afebrile pneumonia associated with Chlamydia trachomatis infection in infants less than 6 months of age. Pediatrics 1979; 63: 192-97. 25. Chiswick ML, James DK. Kielland’s forceps: association with neonatal morbidity and mortality. Br Med J 1979; i: 7-9. 26. Karp LE, Doney JR, McCarthy T, Meis PJ, Hall M. The premature breech: trial of labour or caesarean section. Obstet Gynecol 1979; 53: 88-92. 27. De Crespigny LJC, Pepperell RJ. Perinatal mortality and morbidity in breech presentation. Obstet Gynecol 1979; 53: 141-45. 28. Ahuja GL, Willoughby MLN, Kerr MM, Hutchison JH. Massive subaponeurotic hæmorrhage in infants born by vacuum extraction. Br Med J 1979; ii: 743-45. 29. Graham-Pole JR, Barr W, Willoughby MLN. Continuous-flow exchange plasmapheresis in severe rhesus iso-immunisation. Lancet 1974; i: 1051. 30. Clarke C, Whitfield AGW. Deaths from rhesus hæmolytic disease in England and Wales in 1977: accuracy of record and assessment of anti-D prophylaxis. Br Med J 1979, i: 1665-69. 31. Bowman JM, Chown B, Lewis M, Pollock JM. Rhesus iso-immunisation during pregnancy: antenatal prophylaxis. Can Med Assoc J 1978; 118: 623-30. 32. Willoughby MLN. Anæmias in the neonatal period, 1. rhesus disease (rhesus iso-immunisation) In: Pædiatric hæmatology. Edinburgh: Churchill Livingstone, 1977: 163-79.
1288 to hospital metabolic diets also improved diabetic control, reduced 24 h urinary glucose loss, and
cellulose fibre13 lowered
pre-meal glucose concentrations throughout the
day. Possible Mechanisms
effects.-Breath hydrogen studies8 and the excretion pattern of both xylose6 and paracetamol’4 indicate that the improvement in glucose tolerance produced by consumption of viscous fibres is due to slower absorption of carbohydrate rather than malabsorption. Guar test-meal studies on man and rats suggest that this slow absorption is produced by slower gastric emptying14,15 and slower small-intestinal absorption.16 Intimate mixing, allowing physical interaction between food and fibre, seems important in converting the carbohydrate to what might be termed a slow-release or "lente" form. Purified fibre preparations sprinkled on top of food 17 or taken with the non-carbohydrate portion of the diet17,18 have been ineffective in reducing the blood-glucose rise. In natural fibre-rich foods such as seeds, fibre in the outer coats (as in cereals) or distributed more evenly throughout the seed (as in beans) will also act as a barrier which slows enzymic attack and small-intestinal absorption. Other factors may be involved in addition to the depression of the enteroinsular response after fibrerich meals.19 Intravenous glucose tolerance was improved after fibre intake by mouth even though there was no change in insulin or gastrointestinal peptide conAcute
centrations.2O
Long-term effects.-Insulin requirement and urinary glucose output fell progressively in diabetic patients taking fibre for 2-12 weeks. 10,12,21,22 This could be due to increased insulin production, increased sensitivity to endogenous or injected insulin, or alterations in gut morphology, such as reduction in villus length, favouring slower glucose absorption. There is no evidence for increased production of endogenous insulin, nor are there any studies of small-intestinal structure. Increased sensitivity to insulin may occur and be related to other endocrine or metabolic changes. Reduced 24 h urinary 3-hydroxybutyrate (3-OHB) outputs were found in diabetics on guar-supplemented diets23 while, in normal people, addition of fibre to one glucose load resulted in lower levels of 3-OHB and free fatty acids (FFA) after 4 h and improved tolerance in response to a second glucose load.24 The apparently progressive effect of dietary fibre may, therefore, depend on sustained suppression of free fatty acid release secondary to more prolonged absorption of carbohydrate. One meal may influence the next and metabolic alterations may carry over to each successive day. HYPERLIPIDaeMIA AND FIBRE
Hypolipidaemic Effect of Fibre-supplemented Diets in Normal Subjects Fibre supplements including wheat bran;25,26 fibre extracted from carrots,26 cabbage,26 and apple ;26 bagasse (sugar cane fibre) ;27 cellulose;28 lignin;29,30 psylium husk (’Metamucil’);31 citrus pectin;26,32-37 and guar gum26,34.37 have been given at doses of 5 to 100 g/day. Only the vis-
materials, metamucil, pectin, and guar, consistently lowered total serum cholesterol by 4-16% at doses of 6 to 36 g/day. Neither high density lipoprotein (HDL) cholesterol nor serum triglyceride was lowered. Particulate fibres (e.g., wheat bran) were generally inefcous
fective.25,26 In the few studies with unprocessed high-fibre foods, chick-pea supplements reduced serum cholesterol when taken for over 20 weeks,38 as did dietary supplementation with 100 g brown beans daily39 or substitution of 140 g rolled oats in place of bread .40 However, in only one 7-day experiment where subjects took either a liquid formula diet or a high-starch, high-fibre diet (baked beans, rice, and wholemeal bread) was a fall in triglyceride seen in addition to a cholesterol reduction.4’ Clinical Studies
The use of dietary fibre in hyperlipidaemia has been little investigated. Type-ii hyperlipidmmic patients taking 15-40 g/day guar42,43 or pectin 44 over 2-8 weeks showed lower total serum cholesterol levels. An initial report of a hypocholesterolaemic action of lignin 29 in type-n hyperlipidxmia is now dispUted.3O The falls occurred in the low-density lipoprotein fraction and may therefore be therapeutically useful in reducing the risk of cardiovascular disease. Although purified fibre supplements have not lowered raised triglyceride concentrations, increasing the carbohydrate intake from 40 to 70% with unprocessed high-fibre foods significantly lowered both serum triglyceride and cholesterol concentrations in hypertriglyceridsemic diabetic patients.2’ The replacement of sugar by starch may have been important,45 nevertheless the use of natural highfibre diets warrants further attention. Mechanism
ofaction
The action of fibre in lowering serum cholesterol was originally thought to be similar to that of cholestyramine-i.e., that fibre bound bile salts in the small intestine and prevented their reabsorption. Similarly micelle and chylomicron formation, together with absorption of dietary cholesterol, would also be reduced. Thus when 12 g cholestyramine was added to a fatty test meal,46
postprandial chylomicronsemia was markedly depressed. Unexpectedly, addition of similar amounts of pectin or guar enhanced the postprandial chylomicronaemia.47 Also, guar increased the faecal bile-salt output by only 70%, compared with much larger losses induced by cholestyramine, while the 30% increase in output with pecgreater than with wheat bran, which did not lower serum cholesterol. 48 Thus binding or sequestration of bile salts to increase faecal loss cannot be the full explanation for the hypocholesterolaemic properties of certain dietary fibres.45 Increased neutral steroid loss may be a factor. In addition, by increasing the chylomicronoemia, less dietary fatty acid is available to be taken up directly by the portal vein for hepatic cholesterol synthesis.4’ Decreased postprandial insulin and blood glucose rises may also reduce the stimulus to hepatic cholesterol synthesis. 1,8,1,19 Alterations in colonic metabolism of bile acids which are reabsorbed and other substances produced during degradation of dietary fibre-e.g., methanol produced from
tin
was no
even
1289
high methoxy pectins-may suppress hepatic cholesterol synthesis. ADVERSE EFFECTS
There is
potential mineral and trace eleCereal fibre deficiency. may reduce blood levels of calcium49 and iron,5O and unleavened bread may be responsible for zinc deficiency seen in Iran.5l Cellulose52 also increases calcium losses. Fibre from many sources may bind calcium in vitro.53 However, in vivo, much of this calcium will be made available for colonic absorption as the fibre is degraded. Diabetic patients on over 20 g guar/day for 6 months had no changes in serum levels of calcium, zinc, or copper, but further study of other fibres is needed. 54 Flatulence and loose stools are two major symptoms associated with administration of purified fibre supplements. Responses vary greatly and probably relate to different dietary preference and an individual’s colonic flora. In some, symptoms gradually diminish, while in others symptoms may increase with time. concern over
ment
FUTURE DEVELOPMENTS
Incorporating viscous fibre supplements into foods is difficult. The development of a guar crispbread12.43 and a slow-gelling granulate has allowed the longer-term effects of purified fibre supplements to be explored. Further palatable products are required to facilitate good compliance and allow therapeutic potential to be fully evaluated. The search for useful naturally occurring high-fibre foods and knowledge of the background diet most suited to fibre supplementation is equally important. Initial studies suggest that, in diabetics, guar supplementation is more effective at higher levels of carbohydrate intake. 55 This may also be true for other forms of fibre. Other plant substances now refined out of the Western diet, including enzyme inhibitors, lectins, and saponins, may also lower serum cholesterol or flatten the postprandial glycaemic response by their action within the gut. The combination of two such substances, a fibre, guar, and an enzyme inhibitor, acarbose, has successfully reduced postprandial glycaemia in normal individuals.56 Thus combined intraluminal physical and chemical approaches, which reduce the rate of starch digestion and carbohydrate absorption, may help in the creation of lente carbohydrate for use in diabetic therapy. Many future therapeutic gains may come from combination of substances with different modes of action which have been eliminated from the modern Western diet. I thank Sir Francis Avery Jones, Dr E. N. Rowlands, and Prof. Richard Doll for much help and encouragement. D.J.A.J. was in receipt of funds from the British Diabetic Association and the Medical Research Council.
4.
Cong Ser 1971, 231: 325. 5. Haber GB, Heaton KW, Murphy D. Depletion and disruption of dietary fibre: effects on satiety, plasma glucose, and serum insulin. Lancet 1977; ii: 679-82. 6. Jenkins DJA, Wolever TMS, Leeds AR, et al. Dietary fibres, fibre analogues and glucose tolerance: importance of viscosity. Br Med J 1978; i: 1392-94. 7. Jeffrys DB. The effect of dietary fibre on the response to orally administed glucose. Proc Nutr Soc 1973; 33: 11A. 8. Jenkins DJA, Leeds AR, Gassull MA, Cochet B, Alberti KGMM. Decrease in post-prandial insulin and glucose concentrations by guar and pectin. Ann Intern Med 1977; 86: 20-23. 9. Jenkins DJA, Leeds AR, Gassull MA, et al. Unabsorbable carbohydrates and diabetes: decreased post-prandial hyperglycæmia. Lancet 1976; ii: 172-74. 10. Kiehm TG, Anderson JW, Ward K. Beneficial effects of a high carbohydrate, high fiber diet in hyperglycemic men. Am J Clin Nutr 1976; 29: 895-99. 11. Douglas JM. Raw diet and insulin requirements. Ann Intern Med 1975; 82: 61. 12. Jenkins DJA, Wolever TMS, Nineham R, et al. Guar crispbread in the diabetic diet. Br Med J 1978; ii: 1744-46. 13. Miranda PM, Horwitz DL. High fibre diets in the treatment of diabetes mellitus. Ann Intern Med 1978; 88: 482-86. 14. Holt S, Heading RC, Carter DC, Prescott LF, Tothill P. Effect of gel fibre on gastric emptying and absorption of glucose and paracetamol. Lancet 1979; i: 636-39. 15. Leeds AR, Bolster NR, Andrews R, Truswell AS. Meal viscosity, gastric emptying and glucose absorption in the rat. Proc Nutr Soc 1979; 38: 44A. 16. Caspary W. Effect of dietary fiber on absorption and motility. In: Creutzfeldt
W, Schöffling K,eds.The entero-insularaxis,satellitesymposium totheXth International Diabetes Federation Meeting. Göttingen. 1979: (in press). 17. Williams DRR, James WPT. Fibre and diabetes. Lancet 1979; i: 271-72. 18. Jenkins DJA, Nineham R, Craddock C, et al. Fibre and diabetes. Lancet 1979; i: 434. 19. Morgan LM, Goulder TJ, Tsioladis D, Marks V, Alberti KGMM. The effect of unabsorbable carbohydrate on gut hormones: modification of postprandial GIP secretion by guar. Diabetologia 1979 (in press). 20. Jenkins DJA. Influence of fibre and guar-supplemented food on insulin secretion and glucose tolerance. In: Creutzfeldt W, Schöffling K, eds. The Entero-insular Axis. 1979 (in press). 21. Anderson JW, Ward K. Long term effects of high carbohydrate high fibre diets on glucose and lipid metabolism: a preliminary report on patients with diabetes. Diabetes Care 1978; 1: 77-82.
Jenkins DJA, Wolever TMS, Nineham R, Bacon S, Smith R, Hockaday TDR. Dietary fibre and diabetic therapy: a progressive effect with time. In: Camerini-Davalos RA, ed. Treatment of early diabetes. New York: Plenum Press, 1979: 275-79. 23. Jenkins DJA, Wolever TMS, Nineham R, et al. Dietary fibre and ketone bodies: reduced urinary 3OHB excretion in diabetics on guar. Br Med J (in press). 24. Jenkins DJA, Nineham R, Wolever TMS, et al. Effect of eating guar and glucose on subsequent glucose tolerance. Clin Sci 1979; 57: 26P. 25. Truswell AS, Kay RM. Bran and blood lipids. Lancet 1976; i: 367. 26. Jenkins DJA, Reynolds D, Leeds AR, Waller AL, Cummings JH. Hypocholesterolemic action of dietary fiber unrelated to fæcal bulking effect. Am J Clin Nutr (in press). 27. Walters RL, McLean Baird I, Davies PS, et al. Effects of two types of dietary fibre on faecal steroid and lipid excretion. Br Med J 1975; ii: 536. 28. Shurpalekar KS, Doraiswamy TR, Sundaravalli OE, Rao MN. Effect of inclusion of cellulose in an "atherogenic" diet on the blood lipids of children. Nature 1971; 232: 554. 29. Thiffault C, Bélanger M, Pouliot M. Traitement de l’hyperlipoprotéinémie essentielle de type II par un nouvel agent therapeutique, la celluline. Canad Med Ass J 1970; 103: 165. 30. Lindner P, Möller B. Lignin: a cholesterol lowering agent? Lancet 1973; ii: 22.
1259. 31. Forman DT, Garvin JE, Forestner JE, Taylor CB. Increased excretion of fecal bile acids by an oral hydrophilic colloid. Proc Soc Exp Biol Med
1968; 127: 1060. 32. 33. 34.
35.
36. REFERENCES
37. 1. Trowell HC. Dietary
fibre, ischæmic heart disease and diabetes mellitus. Proc Nutr Soc 1973; 32: 151. 2. University Diabetic Group Diabetes Program. A study of the effect of hypoglycemic agents on vascular complications in patients with adult-onset diabetes. II Mortality results. Diabetes 1970: 19 (suppl.): 789-815. 3. Report from the Committee of Principal Investigators. A co-operative trial in the primary prevention of ischæmic heart disease using clofibrate. Br Heart J 1978; 40: 1067-1118.
GD. Frequency of diabetes with special respect to diet. In: Rodriguez RR, Vallance-Owen J, eds. Diabetes, Proceedings of 7th Congress of the International Diabetes Federation. Amsterdam: Excerpta Medica, Int
Campbell
38. 39. 40.
Fiber and pectin in the diet and serum cholesterol concentration in man. Proc Soc Exp Biol Med 1061; 106: 555. Palmer GH, Dixon DG. Effect of pectin on serum cholesterol levels. Am J Clin Nutr 1966; 18: 437. Jenkins DJA, Leeds AR, Newton C, Cummings JH. Effect of pectin, guar gum and wheat fibre on serum cholesterol. Lancet 1975; i: 1116. Durrington PN, Manning AP, Boulton CH, Hartog M. Effect of pectin on serum lipids and lipoproteins, whole gut transit-time and stool weight. Lancet 1976; ii: 394. Kay RM, Truswell AS. Effects of citrus pectin on blood lipids and fecal steroid excretion in man. Am J Clin Nutr 1977; 30: 171. Fahrenback MJ, Riccardi BA, Saunders JL, Lowrie IN, Heider JG. Comparative effects of guar gum and pectin on human cholesterol levels. Circulation 1965; 31/32 (suppl. 2): 1141. Mather KS, Khan MA, Sharma RD. Hypocholesterolæmic effect of Bengal gram: a long-term study in man. Br Med J 1968; i: 30. Luyken R, Pikaar NA, Polman H, Schippers F. The influence of legumes on the serum cholesterol level. Voeding 1962; 23: 447. De Groot AP, Luyken R, Pikaar NA. Cholesterol-lowering effect of rolled oats. Lancet 1963; ii: 303.
Keys A, Grande F, Anderson JT.
1290
authority would have, by nomination, a consultant, a general practitioner, a nurse, a university representative, and someone from the trade union movement, but disauthorities. Each
National Health Service DISTRICT HEALTH AUTHORITIES THE report of the
Royal Commission on the National which was published five months ago, Health Service, contained more than a hundred recommendations. In its first reaction’ to the report the Government concentrates on only one of them. Many issues are "being studied by the Health Departments through the ordinary machinery". Some possibilities mentioned by the Royal Commission are rejected: regional health authorities are not to be made accountable to Parliament; the N.H.S. will not be handed over to local government; there is to be no additional inquiry into the London health services ; health authorities are not to have chief executives; family practitioner committees are let out of the condemned cell. The only Royal Commission proposal seized on with any enthusiasm is the abolition of the area health authority. In a foreword to the consultative paper, Mr Patrick Jenkin, Secretary of State for Social Services, and Mr Nicholas Edwards, Secretary of State for Wales, say: approach stems from a profound belief that the needs of patients must be paramount. Whatever structure and management arrangements are devised must be responsive to those needs. The closer decisions are taken to the local community and to those who work directly with patients, the more likely it is that patients’ needs will be their prime objective." District health authorities.-With regional health authorities staying as they are, for the time being at least, only one authority would remain in the N.H.S. in England, and this would be at district level serving populations in the range 200 000 to 500 000. Some districts and areas (notably singledistrict ones) would fit the bill already but most multi-district areas will need restructuring, wherever possible along the lines of existing district boundaries. Social geography (e.g., not cutting through established community identities), hospital catch"Our
scale of facilities, and links with local government are the factors to be taken into account when restructuring is discussed. Teaching districts would be too small to meet the requirements of medical schools, so universities would be asked to forge links with more than one of the new authorities. The new authorities would be smaller in membership than the present area ones, and might have twenty members plus a chairman. Local authority representation would be reduced from a third (in A.H.A.s) to about one fifth in the new district ment areas,
trict health staff would not have the right of employee representation. The chairman would be nominated by the Secretary of State and the balance of members by the R.H.A.
Timing.-After the consultation process, the details would be handed over to R.H.A.s which would have until the end of 1983 to implement the structural changes needed. Management arrangements would take even longer since nothing could be done in new districts until they had been set up. Cost.-When the transitional costs (unspecified) have been the proposed changes "together with the general drive in the NHS for greater efficiency" should permit a reduction in management costs of up to 10%. From April 1, 1980, health authorities will be set new objectives for savings on the management side of the N.H.S.
met
Regional health authorities.-These will be responsible, after full consultation, for making proposals for the restructuring of areas. They will also, for the longer term, retain responsibilities for financial control and for coordinating strategic plans. Planning procedures should be simplified to make regional plans more sensitive to district needs. The regions will be expected to leave operational matters primarily to be settled by district health authorities. Family practitioner committees.-These should remain but, where appropriate, one F.P.C. may cover more than one district. Professional advice.-The simplification of the professional advisory committee structure is being looked into by a working-party under the Chief Medical Officer. Community health councils.-The Government is clearly tempted to do away with these councils-next year they will cost C4 million and the new authority members should be less remote from local services than A.H.A. members are-but it limits itself to an invitation to comment on whether C.H.C.s should be retained under the new district structure.
Consultants’ contracts.-There is a strong authorities to hold consultant contracts.
case
for district
Area services.-The changes have implications for ambulance and scientific services and the like, and R.H.A.s would have to approve splitting or sharing arrangements. Comments should be sent, by April 30, 1980, to Regional Liaison Division 5A, D.H.S.S., Euston Tower, 286 Euston Road, London NW3DN, or to the Welsh Office in Cardiff. 1.
Department of Health and Social Security and Welsh Office. Patients First: consultative paper on the structure and management of the National Health Service in England and Wales. H.M. Stationery Office. 1. l.
48.
Jenkins DJA, Leeds AR, Gassull MA, Houston H, Goff DV, Hill MJ. The cholesterol lowering properties of guar and pectin. Clin Sci Mol Med 1976; 51: 8P.
41. Albrink
MJ, Newman T, Davidson PC. Lipid-lowering effect of a very high carbohydrate high fiber diet. Diabetes 1976; 25 (suppl): 324A. 42. Jenkins DJA, Leeds AR, Slavin B, Mann J, Jepson EM. Dietary fibre and blood lipids: reduction of serum cholesterol in type II hyperlipidæmia by guar gum. Am J Clin Nutr 1979; 32: 16-18. 43. Jenkins DJA, Reynolds D, Slavin B, Leeds AR, Jenkins AL, Jepson EM. Dietary fiber and blood lipids: treatment of hypercholesterolemia with guar crispbread. Am J Clin Nutr 1979 (in press). 44. Miettinen TA, Tarpila S. Effect of pectin on serum cholesterol, fecal bile acids and biliary lipids in normolipidemic and hyperlipidemic individuals. Clin Chim Acta 1977; 79: 471-77. 45. Kritchevsky D. Fiber, lipids and atherosclerosis. Am J Clin Nutr 1978; 31: 565-74. 46. Barnard DL, Heaton KW. Bile acids and vitamin A absorption in man: the effects of two bile acid binding agents, cholestyramine and lignin. Gut 47.
1973; 14: 316-18. Jenkins DJA. The action of dietary fibre in lowering fasting
serum cholesterol and reducing postprandial glycæmia: gastrointestinal mechanisms. In: Carlson LA, et al. eds. International Conference on Atherosclerosis. New York, Raven Press 1978: 173-82.
49. Heaton KW, Pomare EW. Effect of bran on blood lipids and calcium. Lancet 1974; i: 49. 50. Jenkins DJA, Hill MS, Cummings JH. Effect of wheat fiber on blood lipids, fecal steroid excretion and serum iron. Am Clin Nutr 1975; 28: 1408-11. 51. Reinhold JG, Parsa A, Karimian N, Hammide JW, Ismail-Beigi F. Decreased absorption of calcium, magnesium, zinc, and phosphorus by humans due to increased fibre and phosphorus consumption as wheat bread. J Nutr
1976; 106: 493. 52. Pak CW, Delea CS, Bartter FC. Treatment of recurrent nephrolithiasis with cellulose phosphate. N Engl J Med 1974; 290: 175. 53. James WPT, Branch WJ, Southgate DAT. Calcium binding by dietary fibre. Lancet 1978; i: 638-39. 54. Jenkins DJA, Reynolds D, Wolever TMS, Nineham R, Taylor, RH, Hockaday TDR. Diabetic control, lipids, and trace elements after six months on guar. Clin Sci 1979 (in press). 55. Jenkins DJA, Wolever TMS, Bacon S, et al. Diabetic diets: high carbohydrate combined with high fiber. Amer J Clin Nutr (in press). 56. Jenkins DJA, Taylor RH, Nineham R, et al. Combined use of guar and acarbose in reduction of postprandial glycæmia. Lancet 1979; ii: 924.
