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NUTRITION IN MEDICINE: WHAT IS ITS PLACE? George A. Bray The threads of nutrition in medicine go back to the classic clinical studies of Lind in which oranges and lemons were found to prevent scurvy (Stewart and Guthrie, 1953~. At nearly the same time, Lavoisier and de La Place (1780) and Crawford (1979) introduced the study of metabolism and showed that combustion by a candle and metabolism in the body produced similar amounts of heat. When Graham Lusk, one of the pioneers in nutritional science, wrote the first edition of The Elements of the Science of Nutrition in 1906 (tusk, 1906), more than half of the book was devoted to the concepts of energy metabolism and a smaller part was devoted to some of the endocrine glands. These important ideas about the way in which the body handles the major components of the diet are still a central theme in the nutrition education of the physician. During the first half of the twentieth century, a second theme originating in the work of Lind was picked up and led to the identification, isolation, and synthesis of vitamins (Goldberger et al., Hopkins, 1912; 1926; Rickes et al., 1948; and Szent-Gyorgi, 1928~. Thiamin and riboflavin led the way, followed by the other water-soluble vitamins and the fat-soluble vitamins. In 1948, vitamin Big, cyanocobalamin, was the last of the vitamins to be identified and accepted. With the closure of the field of active identification and isolation of the major vitamins, many people thought that nutritional problems had come to an end and that the scientific basis for nutrition could be taught to physicians through courses in biochemistry and physiology. Scientific and clinical developments in the last quarter century, however, have shown that there are still many unsolved nutritional problems with important clinical implications that need to be included in the curriculum. 191
Malnutrition, which is so prevalent in many underdeveloped and rapidly developing countries, came into prominence in the United States in the 1960s. The political arena was soon alive with examination of a subject as gripping as ~hunger. n As one indication of this political visibility, Senator E.G. Hollings published a book in 1970 entitled The Case against Hunger: A Demand for a National Policy (Hollings 1970~. To quote, "One of the nation's most appalling tragedies is the plight of millions of Americans for whom hunger is an every day fact of life" (Hollings, 1970~. During much of the decade that followed, the U.S. Senate Select Committee on Nutrition end' Human Needs, and more recently the U.S. Senate Subcommittee on Nutrition, have focused on'the extent of malnutrition in'the United States. One outgrowth of the political and public concern has been the increased activity in nutritional surveillance of the American people, as witnessed by the National Health and Nutrition Examination Survey (NHANES), which has now completed three major surveys and is beginning a survey of select segments of the population in which malnutrition may be more prevalent. The Ten State Survey from the Center for Disease Control (U.S. Department 'of Health, Education, and Welfare, 1972) was a second evidence of the heightened public concern with documenting and then eradicating the pockets of malnutrition that might exist. As the search for malnutrition in this country increased, politicians gradually came to the conclusion that the major U.S. nutritional problems were associated with overnutrition and such illnesses as coronary artery disease, obesity, diabetes, hypertension, and dental disease rather than undernutrition'(Bray, 1979~. As a result of this concern, the U.S. Senate Select Committee on Nutrition and Human Needs (1977) published Dietary Goals for the United States. Concern about the desirability of national dietary goals was expressed from many quarters, including professional groups. Whatever the value of such goals, however, the scientific basis on which the relationship between dietary factors and disease rests comes from nutritional investigations undertaken by scientists and physicians. The growing interest in the relation of nutrition'to disease has posed a challenge to ' those interested in nutritional education in medicine. It has made it 192
necessary for physicians in training to have a broader understanding of the human diet and its relation to the diseases that they treat. Following the publication of Dietary Goals for the United States, the U.S. Government released the Dietary Guidelines for Americans (U.S. Department of Health, Education, and Welfare, 1979~. A second scientific review of the same data led to substantiation of the dietary guidelines in a new edition. The American Society for Clinical Nutrition (1979) has published a careful assessment of the data relating to diet and disease. More recently, the National Research Council's Committee on Diet and Health and Surgeon General of the U.S. Public Health Service developed reports on nutrition (DHHS, 1988; NRC, 1989) Any program of nutrition education for physicians must deal with the kinds of information on which these recommendations to the public are based. . A final element that impinges on the training of physicians, in both the undergraduate and the graduate years, is the rapid expansion of techniques for feeding patients through both parenteral and enteral routes. Although blood transfusions were well established by World War II, the use of other intravenous fluids was limited to volume expanders and isotonic solutions. - During the past quarter century, the development of improved catheters, the ability to place such catheters in the major veins, and the potential for long-term maintenance of energy and nutritional needs have added a new dimension to the importance of nutrition education and clinical care for physicians. In the years ahead, the use of parenteral nutrition for a growing list of chronic problems will make understanding of nutritional principles important for all physicians. Medicine must deal with this explosion of nutritional information in three different areas: · It must provide knowledge of normal nutrition and the relation of abnormal nutrition to diseases of deficiency or surfeit. ~ It must develop understanding of the relation of nutrients in the diet to the growing number of drugs that are used. 193
· It must prepare physicians to understand the nutritional problems associated with chronic parenteral and enteral feeding. NUTRITION IN UNDERGRADUATE MEDICAL EDUCATION The need to teach physicians more about nutrition has been known for years. The American Medical Association (AMA) and the Nutrition Foundation sponsored a 1962 conference on the teaching of nutrition in medical schools, after an AMA survey found that "medical education and medical practice have not kept abreast of the tremendous advances in nutritional knowledge" and "there is-inadequate recognition, support, and attention given to this subject in medical schools." The quality of the nutritional curriculum in medical schools was reevaluated 10 years later. The conference at which this reevaluation took place was designed to "formulate realistic practical guidelines for incorporation of nutrition education into medical training in concurrence with the physician's responsibility" for health care. Many participants at the 1972 conference felt that little progress had been made during the intervening 10 years and that the quality and quantity of nutrition education in medical curricula were in need of improvement (White et al., 1972~. A third survey was conducted in 1976 when a questionnaire on nutrition education was mailed to 124 medical schools by the AMA and 123 schools, including 9 new schools, responded. Thirty medical schools reported that they required courses in nutrition; this encompassed just over 25% of the medical students. Elective courses were offered by 82 medical schools. Only 16 schools offered clinical clerkships in clinical nutrition. Of the 30 medical schools reporting that they required courses in nutrition, 25 of them offered these courses during the basic science curriculum, and 7 had requirements for course work during the clinical portion of the curriculum. Of the 82 schools reporting elective nutrition courses for medical students, 22 offered nutrition courses during the clinical years, 39 offered them during the basic science years, and 31 offered them at any time during the 4-year curriculum. In summary, then, in 1976, 64 medical schools offered nutrition 194
courses in the basic science years, 72 offered nutrition courses in the clinical years and 31 schools offered nutrition courses throughout the curriculum. Two medical schools did not designate required nutrition course placement. Ninety-seven percent of U.S. medical schools incorporate instruction in nutrition throughout the curriculum (U.S. Senate, Subcommittee on Nutrition, l9J9) of nutrition education in medical schools (White and Geiger, 1980~. The issue was taken up again in 1979 by the Senate Subcommittee on Nutrition, which requested a report from the General Accounting Office on the state of nutrition education in medical schools (U.S. Senate, Subcommittee on Nutrition, 1979~. Six of the 10 leading causes of death in the United States (heart disease, cancer, cerebrovascular diseases, diabetes, arteriosclerosis, and cirrhosis) have been linked to poor nutrition. Various nonfatal conditions have also been traced to poor nutrition; dental decay is one example. "Although nutrition is important in medicine, it is not taught adequately in many U.S. medical schools. As a result, many physicians may not know as much as they should know about how to make nutritional assessments or counsel patients about diet. Medical schools train physicians primarily to look for and treat nutrition-related diseases after they occur rather than preventing them through nutritional assessment and dietary counseling" (U.S. Senate, Subcommittee on Nutrition, 1979~. The situation has not changed in the past decade. This was made clear in a recent report on Nutrition Education in U.S. Medical- Schools by a Food and Nutrition Board Committee (National Research Council, Committee on Nutrition in Medical Education, 1985~. In 1979, 24% of medical schools had a nutrition course identified~as such; this value increased to only 27% in 1983. Similarly, the percentage of schools offering electives in nutrition rose from only 54% to 64% over the same interval. Much of the nutrition education offered was available in the first 2 years of school. An outline of a core curriculum for the nutrition education of a medical school undergraduate is shown in Table 1. Of 39 schools that provided reliable information, the average total number of hours required for nutrition education was 21. However, 20% of the schools taught fewer than 10 hours and only 10% taught more than 40 hours. The 195
TABLE 1 Elements of a Core Curriculum Energy balance Specific nutrients and dietary components Nutrition in the life cycle Nutritional assessment Protein-energy malnutrition Nutrition in disease prevention and treatment Diversity of dietary practices percentage of schools teaching various topics was also surveyed. Energy balance, obesity, undernutrition, protein carbohydrate, lipid metabolism, and the major vitamins and minerals were taught in more than 80% of the schools. However, the relationship of nutrition to the immune system, renal disease, cancer, the central nervous system, and various phases of the life cycle was taught in less than 60% and in some cases as little as 30% of the medical schools (National Research Council, Committee on Nutrition in Medical Education, 1985~. While some nutrition appears to be taught in more than half of the medical schools, strengthening of the nutrition curriculum is necessary. As recommended in the Food and Nutrition Board's report on nutrition education, one reasonable and logical way to do this would be for each school to engage a physician as a focal point for nutrition education, mentioned above, to pull nutrition training together so that any weaknesses in the teaching of this subject could be identified. This key individual should be placed in an existing department of the medical school and should be a physician with a special interest and capability in nutrition who would be available for teaching and research. 196
; POSTGRADUATE CLINICAL NUTRITION TRAINING The slow rate at which nutrition education has expanded in the undergraduate medical curriculum is mirrored in the progress in postgraduate nutrition education. Nearly 10 years ago, reports from the University of Alabama (Weinsier et al., 1979) and from the New England Deaconess Hospital (Bistrian et al., 1974, 1976) in Boston pointed out the frequency of malnutrition in patients on medical and surgical services. The data from the New England Deaconess Hospital are summarized in Table 2. There were significant abnormalities in this TABLE 2 Prevalence of Hospital Malnutrition Prevalance (%) Surgical Medical Service Service Criterion Triceps skinfold 46 76 Arm muscle circumference 48 55 Albumin -- 44 SOURCE: Bistrian et al. (1974, 1976~. group of patients. There was a deterioration in the nutritional status in 50% or more of the patients, depending on the criterion selected. Patients who satisfied the criteria for malnutrition on admission had a greater likelihood of a longer hospital stay and increased mortality compared with those without these criteria (Weinsier et al., 1979~. The likelihood of malnutrition in that study increased with the length of hospitalization. Butterworth (1974), in a paper with the catchy title The Skeleton in the Hospital Closet, n pointed out that as many as three-fourths of the patients with normal nutritional status at the time of admission to the hospital were found to have an abnormal 197
nutritional status by the end of their hospital stay. Hill et al. (1977) pointed out that among 105 surgical patients, abnormalities in nutritional status~were as high as 50% among those who were still in the hospital more than 1 week following mayor surgery. The realization that malnutrition could occur in a substantial number of patients in American hospitals and the development of techniques for delivering nutritional support to medical and surgical-patients by enteral and parenteral methods led to the expansion of postgraduate training programs in clinical nutrition. Data from the University of Pennsylvania Hospital showed that the number of patients receiving nutritional support in 1979-1980 totaled 13,749 patient-days, a figure that nearly doubled to 23,245 patient-days by 1983-1984 (American Society for Clinical Nutrition, Committee on Education and Training, Subcommittee on Postdoctoral Training, 1986~. In 1979 and 1980 the outpatient component of this nutrition program was less than 25%, while by 1983-1984 the outpatient component rose to nearly 501. This increase in the number of outpatients has occurred in many other hospitals where nutrition support teams are available. The distribution of training programs for clinical nutrition is shown in Table 3 (Heymsfield et al., TABLE 3 Clinical Nutrition Programs Programs Total No. · Medical schools thought to offer91 nutrition training · Had no nutrition program18 · Had a nutrition program72 · Major focus -40 · Minor focus27 · In planning stage5 · M.D.s trained from 1976 to 1981470 SOURCE: Howard and Bigaduette (1983~. 198
1985~. More than 60 programs can be identified throughout the United States, but there is less than one program for every two medical schools. When it is realized that several of these programs are attached to the same medical school, it becomes clear that the opportunities for training in clinical nutrition and the distribution of expertise in this area is geographically inappropriate. Between 1976 and 1981, 470 physicians were trained~in 67 programs in the United States (Howard and Bigaduette, 1983~. Of these, 40 programs had nutrition as a major focus and 27 had nutrition as only a minor component. To establish criteria for effective nutritional programs at the postgraduate medical school level, a conference on clinical nutrition was sponsored by the American Society for Clinical Nutrition in 1984 (American Society for Clinical Nutrition, Committee on Education and Training, Subcommittee on Postdoctoral Training, 1986~. Programs in clinical nutrition can be identified in departments of medicine, surgery, and pediatrics; but the majority are in internal medicine. Funding support for these programs comes through a variety of mechanisms, including local and federal sources. In the most recent survey published in 1987 (Merritt et al., 1987), there appears to have been very little further growth in the number of clinical nutrition training programs available at medical schools at the postgraduate level. In 1983, 67 programs were identified compared with 69 programs in 1987. Thus, like nutrition education at the undergraduate level, growth in nutrition training at the postgraduate level has nearly stalled. That there is a need to improve the quality of nutritional education is made clear by a recent report from the Johns Hopkins Hospital (Roubenoff et al., 1987~. One house staff team was evaluated before and after a brief training program in nutritional assessment. Initially, only 12.5% of the patients who were at nutritional risk were appropriately diagnosed by the house staff. Following the intensive training program in nutritional assessment, 100% of patients deemed to need nutritional services were identified and treatment was initiated. The distressing part of this report, however, was that in a major teaching hospital, recent medical school graduates identified less than 20% of those patients who were in need of nutritional therapy! 199
QUALITY ASSURANCE Identifying clinical nutrition training programs is one thing, but ensuring that those who come out of those programs are well-trained is another. Beginning more than 40 years ago, the American Board of Nutrition started a testing procedure by which physicians and scientists claiming nutritional competence could be evaluated critically. The American Board of Nutrition provides an annual examination for individuals with medical or doctoral degrees who wish to take the examinations certifying them for human or clinical nutrition. With support from the American Society for Clinical Nutrition and the American Society of Parenteral and Entera1 Nutrition, the quality of the examination procedure has steadily improved. SUMMARY AND RECOMMENDATIONS · Nutrition education should be an identifiable component of all undergraduate medical education. This can best be done by identifying a physician scientist in each medical school who is committed to teaching and research in clinical nutrition. ~ Nutritional assessment should be an integral part of the course on the introduction to clinical medicine. The National Board of Medical Examiners should be encouraged to increase the number and quality of questions in nutrition as a procedure for ensuring that undergraduate education in nutrition is of sufficient quality. · Postgraduate training programs for physicians interested in clinical nutrition should become more widely available to meet the geographic and educational needs of the entire nation. · Hospital malnutrition should be reduced by 50% by the year 2000 by implementing clinical nutrition teams, including a physician, in every hospital that receives Medicare funds. 200
· Nutritional services should~be identified in the International Classification of Diseases (9th and subsequent editions) and should be compensated for by federal and nonfederal health care providers. · Third-party providers of health care should require that those physicians and other support personnel delivering nutritional services meet minimum standards of training and that this be certified by an examination process. REFERENCES American Society for Clinical Nutrition. 1979. Nutrition and Your Health: Dietary Guidelines for Americans. Report of the Task Force on the Evidence and Welfare. U.S. Government Printing Office, Washington, D.C. American Society for Clinical Nutrition, Committee on Education and Training, Subcommittee on Postdoctoral Training, 1986. A Report on the Conference on Clinical Nutrition Training for Physicians. Am. J. Clin. Nutr. 44:135-153. Bistrian, B.R., G.L. Blackburn, E. Hallowell, and R. Heddle. 1976 patients. .T Bistrian, R.B., G.L J. Naylor. 1976. _ . Protein status of general surgical J. Am. Med. Assoc. 230:858-860. .. Blackburn, J. Vitale, D. Cohran, and Prevalence of malnutrition in general medical patients. J. Am. Med. Assoc. 235:1567-1570. Bray, G.A., ed. 1979. Obesity in America. DREW Publ. No. NIH 79-359. U.S. Government Printing Office, Washington, D.C. Butterworth, C.E. 1974. The skeleton in the hospital closet. Nutr. Today 9:4-8. Crawford, A. 1979. Experiments and Observations on Animal Heat. London. DHHS (U.S. Department of Health, Education, and Welfare). 1972. Ten State Nutrition Survey, 1968-1970. Report 72-8131. ~ ~ ~ ~ Act. .. .. D.C. DHHS GAS. Department of Health and Human Services). 1979. Nutrition and Your Health: Dietary Guidelines for Americans. U.S. Government Printing Office, Washington, D.C. up.. Government Printing ottlce, Washington, 201
DHHS (U.S. Department of Health and Human Services). 1988. The Surgeon General's Report on Nutrition and Health. DHHS (PHS) Pub. No. 88-50210. Public Health Service, U.S. Department of Health and Human Services. U.S. Government Printing Office, Washington, D.C. 712 PP ~ Goldberger, J., G.A. Wheeler, R.D. Lillie, and L.M. Rogers. 1926. A further study of butter, fresh beef, and yeast as pellagra preventives with consideration of the relation. Public Health Rep. 41:297-318. Heymsfield, S.B., L. Howard, W. Heird, and J. Rhoads. 1985. Biennial survey of physician clinical nutrition training programs. Am. J. Clin. Nutr. 42:152-165. Hill, G.L., R.L. Blackett, I. Pickford, L. Burkinshaw, G.A. Young, J.V. Warren, C.J. Schorah, and D.B. Morgan. 1977. Malnutrition in surgical patients. Lancet i:689-692. Hollings, E.G. 1970. The Case against Hunger. A Demand for a National Policy. Cowles Book Co., New York. Hopkins, F.G. 1912. Feeding experiments illustrating the importance of accessory factors in normal dietaries. J. Physiol. 44:425-460. Howard, L., and J. Bigaduette. 1983. A survey of physician clinical nutrition training programs in the United States. Am. J. Clin. Nutr. 38:719-729. Lavoisier, A.L., and P.S. de La Place. 1780. Memoire sur la Chaleur. P. 355. Memoires de l'Academie des Sciences. Lusk, G. 1906. The Elements of the Science of Nutrition. W.B. Saunders, Philadelphia. Merritt, R.J., S.B. Heymsfield, and L. Howard. 1987. Biennial survey of physician clinical nutrition training programs. Am. J. Clin. Nutr. NRC (National Research Council). 1985. Nutrition Education in U.S. Medical Schools. Report of the Committee on Nutrition in Medical Education, Food and Nutrition Board. National Academy Press, Washington, D.C. NRC (National Research Council). 1989. Diet and Health: Implications for Reducing Chronic Disease Risk. A report of the Food and Nutrition Board. National Academy Press, Washington, D.C. Rickes, E.L., N.G. Brink, F.R. Koniuszy, T.R. Wood, and K. Folkers. 1948. Crystalline vitamin B12. Science 107:296-397. 202
Roubenoff, R., R.A. Roubenoff, J. Preto, and C.W. Balke. 1987. Malnutrition among hospitalized patients. A problem of physician awareness. Arch. Int. Med. 147:1462-1465. Stewart, C.P., and D. Guthrie. 1953. Lind's Treatise on Scurvy. A bicentenary volume containing a reprint of the first edition of a Treatise of the Scurvy by James Lind, M.D. with additional notes. P. 145. Edinburgh University Press, Edinburgh. Szent-Gyorgi, A. 1928. Observations on the function of peroxidase systems and the chemistry of the adrenal cortex. Description of a new carbohydrate derivative. Biochem. J. 22:1387-1409. U.S. Senate, Select Committee on Nutrition and Human Needs. 1977. Dietary goals for the United States. Committee Print. 95th Cong., 1st sees., 1st ed. U.S. Senate, Subcommittee on Nutrition. 1979. Greater Federal Efforts Are Needed to Improve Nutrition Education in U.S. Medical Schools. Report CED-80-39. U.S. General Accounting Office, Washington, D.C. Weinsier, R.L., E.M. Hunker, C.L. Krumdieck, and C.E. Butterworth, Jr. 1979. Hospital malnutrition. A prospective evaluation of general medical patients during the course of hospitalization. Am. J. Clin. Nutr. 32:418-426. 1980. Nutrition in the medical curriculum: An American perspective. Pp. 280-286 in A.N. Howard and I. McLean Baird, eds. Recent Advances in Clinical Nutrition. John Libby, White, P.L., and E.J. Geiger. London. White, P.L., L.K. Mahan, and M.E. Moore, eds. 1972. Conference on Guidelines for Nutritional Education in Medical Schools and Postdoctoral Training Programs, June 25-27, 1972, Williamsburg, Va. American Medical Association, Chicago. 203
