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Ongoing activities

To address a number of the problems mentioned here a project has been awarded to EUROFOODS by the European Community. This involves co-operative efforts between 17 countries towards the development of a merged European food composition data bank. The five aspects of the pilot project are:

1. Inventorization of existing food-nutrient data bases, and examination of the needs of current and potential users of European nutrient data bases.

2. Examination of the differences between national food composition tables, and proposal of ways in which they might be better harmonized.

3. Development of a common coding system for foods for use in the harmonization of nutrient tables and collection of food-intake information.

4. Estimation of the operational requirements of a merged European nutrient data bank system.

5. Establishment of a mechanism for consultation with member states.

Three workshops have taken place with the central theme involving the development of a common food coding and identification system. In the Federal Republic of Germany, a commission with members from four European countries which developed a German Food Code (the BLS [19]) has been actively involved since the beginning of 1984 in developing a draft for this common EUROCODE. Additionally, English translations of the foods presented in 16 of the European food composition tables are currently available in a data file in Heidelberg, along with their EUROCODE 2 number. Efforts are now being undertaken to collect and translate into English typical national dishes and their recipes.

An example of governmental encouragement of standardization in the dietary assessment methodology is the current situation in the Federal Republic of Germany. One of the major research funding agencies, the Ministry of Research and Technology, is requesting that all new projects incorporating dietary assessment incorporate as far as possible the existing standards and the BLS, the Federal Food Code.

Summary

Discussions of food tables should not be divorced from dietary intake assessment methods. The users of food-nutrient information, particularly in the field of nutritional epidemiology, need a complete system with which information can be accurately and in standardized form collected, coded, and translated into nutrient composition data. The current state of affairs is such that most individuals working in this field must create their own system. The wide range of previously mentioned possibilities for variation and error practically excludes the possibility of comparing results between studies. International epidemiology suffers from all these problems, in addition to the problems of language, mixed dishes, and different foods. These users, who can potentially contribute greatly through their findings to the public health of nations through elucidation and quantification of the role of dietary behaviour on the etiology of disease, should not be neglected in the general consideration of the users of and need for food composition data.

References

1. K. J. Acheson, I. T. Campbell, O. G. Edholm, D. S. Miller, and M. J. Stock, "The Measurement of Food and Energy Intake in Man: An Evaluation of Some Techniques," A.J.C.N., 33: 1147-1154(1980).

2. L. Arab, ``Coding and Entry of Food Intakes," in R. Tobelmann, ea., Proceedings of Eighth National Nutrient Data Bank Conference, July 25-27, 1983, Minneapolis, Minnesota (National Technical Information Service, Springfield, Va., 1983), pp.13-22.

3. L. Arab, 'Summary of Survey of Food Composition Tables and Nutrient Data Banks in Europe," in C. E. West, ea., "EUROFOODS: Towards Compatibility of Nutrient Data Banks in Europe," Anna/s of Nutrition and Metabolism, 29 (Suppl. I ): 39-45 (1985).

4. L. Arab and M. Wittler, A Comparision of Food Composition Tables in Europe (in press).

5. G. H. Beaton, J. Milner, A. P. Corey, et al., ``Sources of Variance in 24-hour Dietary Recall Data: Implications for Nutrition Study Design and Interpretation," A.J.C.N., 32: 25462559 (1979).

6. O. Bellin and L. Arab, "ESSEKAN - ein Standardisiertes 24-Stunden-Erinnerungsprotokoll ûber körperliche Aktivitat und Nahrungsmittelaufnahme,' in L. Arab and G. Karg, eds., Entwicklung und Benutzang von Nahrstoff-Datenbanken in der Bundesrepublick Deutschland (Bundesforschungsanstalt fur Ernährung, Karlsruhe, 1984), pp.192-203.

7. S. Gingham, "Premise and Methods," in G. G. de Backer, H. T. Pedoe, and P. Ducimetiere, eds., Surveillance of Dietary Habits of the Population with regard to Cardiovascular Diseases EURONUT Report, no. 2 (Stichting Nederlands Instituut voor de Voeding, Wageningen, 1983), pp.21-42.

8. A. Ferro-Luzzi, "Standardization within and between Centers," in G. G. de Backer, H. T. Pedoe, and P. Ducimetiere, eds., Surveillance of Dietary Habits of the Population with regard to Cardiovascular Diseases, EURO-NUT Report, no. 2 (Stichting Nederlands Instituut voor de Voeding, Wageningen, 1983), pp. 51-60.

9. G. C. Frank, A. T. Hollatz, L. S. Webber, and G. S. Berenson, "Effect of Interviewer Recording Practices on Nutrient Intake - Bogalusa Heart Study," J. Am. Diet. Assoc., 84(12): 1432-1439 (1984).

10. 1. G. A. J. Hautvast and W. Klaver, eds., The Diet Factor in Epidemiological Research, EURO-NUT Report, no. I (Ponsen and Looyen, Wageningen, 1982).

11. L. Hoover, "Computerized Nutrient Data Bases: 1. Comparison of Nutrient Analysis Systems," J. Am. Diet. Assoc., 82(5): 501-505 (1983).

12. A. Keys, "Dietary Survey Methods," in R. 1. Levy, B. M. Rifking, B. H. Dennis, and N. D. Ernst, eds., Nutrition, Lipids, and Coronary Heart Disease, A Global View (Raven Press, New York, 1979), pp.123.

13. J. P. Madden, S. 1. Goodman, and H. A. Guthrie, "Validity of the 24-hour Recall," J. Am. Diet Assoc.,68: 143- 147 (1976).

14. A. Marsh, "Problems Associated with Recipe Analysis," in R. Tobelmann, ea., Proceedings of Eighth National Nutrient Data Bank Conference, July 25-27, 1983, Minneapolis, Minnesota (National Technical Information Service, Springfield, Va., 1983), pp. 29-38.

15. R. H. Matthews and Y. J. Garrison, Food Yields Summarized by Different Stages of Preparation, Agriculture Handbook 102, (USDA, Washington, D.C., 1975).

16. National Research Council, "Methodology," Diet, Nutrition, and Cancer (National Academy Press, Washington, D.C., 1982), pp. 30-50.

17. J. Perisse, "The Heterogeneity of Food Composition Tables," in J. G. A. T. Hautvast and W. Klaver, eds., The Diet Factor in Epidemiological Research, EURO-NUT Report, no. I (Ponsen and Looyen, Wageningen, 1982), pp. 100-105.

18. H. Pfannendorfer and L. Arab, "KALI-Kodierungs- und Auswertungs-programm fur Lebensmittellnhaltsstoffe," in L. Arab and G. Karg, eds., Entwicklung und Benutzung von NahrstoffDatenbanken in der Bundesrepublick Deutschland (Bundesforschungsanstalt fur Ernahrung, Karlsrnhe, 1984), pp. 137-147.

19. H. Rottka, "Bundeslebensmittelschlussel (BLS)," in L. Arab and G. Karg, eds., Entwicklung und Benutzung von Nahrstoff-Datenbanken in der Bundesrepublick Deutschland (Bundesforschungsanstalt fur Ernahrung, Karlsruhe, 1984), pp. 126-129.

20. D. A. T. Southgate and H. Greenfield, Guidelines to the Production, Management and Use of Food Composition Data Systems (in press).

21. W. A. van Staveren and J. Burema, "Validity and Reproducibility of Methods," in G. G. de Backer, H. T. Pedoe and P. Ducimetiere, eds., Surveillance of Dietary Habits of the Population with regard to Cardiovascular Diseases, EURO-NUT Report, no. 2 (Stichting Nederlands Instituut voor de Voeding, Wageningen, 1983), pp.43-50.

22. C. E. West ea., "EUROFOODS: Towards Compatibility of Nutrient Data Banks in Europe," Annals of Nutrition and Metabolism, 29 (Suppl. 1): 1-72 (1985).

NCI food data needs: impact on coding systems

Introduction
International research
United States studies
Local research
Individual level
Uses of food composition data
Implications for infoods
Summary

RITVA R. BUTRUM
National Cancer Institute, Washington, D.C., USA

Introduction

The National Cancer Institute (NCI) supports many different types of research on the relationship between nutrition and cancer, including studies in prevention, epidemiology, etiology, basic cellular mechanisms, treatment, and information dissemination. As a result of conducting this research, major deficiencies in existing food data bases have become apparent. Problems range from the unavailability of food data to questionable data validity, reliability, accessibility, and interpretation.

Food data problems are especially evident in epidemiologic studies, which focus on populations' dietary differences and their relationships to cancer incidence. International variations in diet can be distinguished by broad nutrient-food categories, but detailed information is lacking on the nutrient content of many foodstuffs consumed by different peoples and their subgroups. In addition, comprehensive data are unavailable for the non-nutrient chemical components of food, which represent protection for, or risks to, good health.

Thus, creating a comprehensive food composition data network as proposed by INFOODS, covering the spectrum of biologic activity from nutrients to contaminants, would greatly aid cancer epidemiologists, researchers, clinicians, educators, and public policy-makers. The purpose of this paper is to highlight selected NCI-supported projects which would benefit from the development of such a system. Table 1 presents users of food composition data at the international, national, local, and individual levels. The objectives of each of these researchers' projects is then discussed with their needs relative to the development of an internationally acceptable coding system.

International research

At the international level, NCI is supporting a variety of diet, nutrition, and cancer studies involving food composition data. The first study, now in progress in Puerto Rico, is examining the exposures of staple foods to high levels of toxic substances such as pesticides and chemical fertilizers. Many Puerto Ricans derive a major source of their caloric intake from maize, which may be the principal vehicle for exposing the population to potential carcinogens.

Table 1. NCI-supported research projects

a. Research at the international level. b. Research at the national level. c. Research at the local level. d. Research at the individual level.

NCI also is supporting a number of studies in China, where the unique distribution of nutrients in the soil provides a natural laboratory for studying disease. For example, areas of the terrain differ widely in selenium content, and evidence exists that selenium deficiency may be associated with increased cancer risk. Another prevention intervention study in China involves administering multiple vitamin/mineral preparations containing beta-carotene to oesophageal dysplasia patients. Although a rare tumour in the United States, 20 per cent of the deaths in Linxian, China, are due to oesophageal cancer. A prominent part of the population's diet consists of pickled foods, which are suspected to produce carcinogens over time. It has been suggested that the micronutrient deficiencies, in combination with the carcinogenic substances, lead to cancer. A second, related trial involves administering a series of micro-nutrients to a general Chinese population using a multi-factorial design.

Among the international laboratory studies being supported by NCI is a project that began by looking at the possible cancer-promoting effects of saccharin and tryptophan in human and rat bladder tissues. The London researchers now are comparing the effects of these cancer promoters to anti-promoters such as retinoids, and are gearing up for human prevention studies.

Finland provides a unique resource for studying the intervention of beta-carotene and vitamin E in a population of heavy smokers. Because of the country's past problems with tuberculosis, its public health service requires every male smoker to have an annual chest X-ray. This practice provides an opportunity to superimpose a low-cost nutritional intervention study into a system which already provides population surveillance, and good record-keeping. The five-year, double-blind randomized trial will also include a dietary survey of persons from the original cohort who subsequently developed cancer.

With respect to cancer treatment, researchers in Toronto, Canada, are studying perturbations of various nutritional parameters in breast and lung cancer patients, and are examining whether these deficiencies are correctable with existing methods of nutritional intervention. Investigators are applying expertise in nutritional assessment and in measurement of total body nitrogen with neutron activation.

United States studies

Within the United States, NCl's nutritional focus comprises two areas: (a) diet and cancer prevention, and (b) chemoprevention. Current and proposed projects that could benefit from the development of INFOODS include a large epidemiologic investigation, which is examining dietary patterns of the migrant Japanese in Hawaii and cancer incidence. Using epidemiologic data and sera samples collected from 1965 to 1968, incident cancer cases are being evaluated. The study also will examine the relationship between future cancer incidence and intakes of dietary fat, fibre, alcohol, dietary nitrates, salt, vegetables, and other food constituents.

A multi-institution clinical trial, now under way in eight US cities, is studying the effect of a low-fat diet (i.e. 20 per cent of total calories) on women at high risk for breast cancer. This protocol will test whether manipulation of dietary fat will slow or halt the subsequent promotion phase of cancer in women who have a predisposition for breast cancer.

The need for a comprehensive food data system such as that proposed by INFOODS is shown in studies on dietary fibre at Cornell University and the University of Wisconsin. Among the problems with existing fibre data are lack of standardized analysis techniques on representative foods, incomplete data, and lack of information about the meaning of current fibre values. Van Soest and Marlett are working to develop methods for fibre analysis and to analyse total fibre and individual dietary fibre components in US foods.

Similar dietary data problems exist for the food composition of carotenoids and retinoids. NCI supports several case-control studies that seek to demonstrate that levels of vitamin A consumption affect the development of colonic adenomatous polyps and adenocarcinoma. One three-year clinical trial using beta-carotene will attempt to slow the rate of polyp development and redevelopment. Vitamin A status will be assessed through blood plasma levels and dark adaptation tests. The advantage of using colonic adenomatous polyp formation, a pre-cancerous condition, as an endpoint in this trial is that the condition has a short development and redevelopment time in many patients.

In other related studies, vitamin A is being administered to persons with asbestosis, for treatment of lung mesothelioma, and to chronic and former smokers for prevention of lung cancer. Women at high risk for cervical dysplasia are taking retinyl acetate in two other trials.

A new area of NCI-sponsored research involves identifying, characterizing, and validating the dietary markers of past or present dietary exposure to cancer. Various problems exist in interpreting data derived from current nutritional assessment techniques. Moreover, the latency period of carcinogenesis poses several problems in gathering information about past dietary habits, namely that: (a) current dietary intakes may not be representative of past intakes, since dietary patterns change over time, and (b) our knowledge of the changing composition of foods is limited. Markers of both present and past dietary experience, therefore, will be especially useful in nutritionally focused studies in cancer epidemiology.

Local research

Clinical Nutrition Research Units (CNRUs) are an example of NCI-supported activities at the local level that would benefit from an integrated food data system. CNRUs are designed to create or strengthen nutrition research, training, and education through co-ordinated effort, intellectual stimulation, and use of shared resources. Each CNRU consists of: research with human subjects and populations; laboratory investigations; research training; educational programmes for medical students, house staff, practicing physicians, and paramedical personnel; nutritional support services; public information activities; and shared facilities and research services.

The NCI supports two CNRUs: one at the University of Alabama in Birmingham, and the other at the Memorial Sloan-Kettering Cancer Center, New York Hospital Cornell Medical Center, and Rockefeller University in New York. Primary areas of research at the University of Alabama concern malnutrition of hospital patients, nutrition and cancer feeding problems, vitamin status assessment, and folic acid biochemistry and metabolism. In one study, researchers found that the intakes of women with cervical dysplasia were often low in ascorbate and deficient in folate. Moreover, folate supplementation resulted in reversal of the dysplasia. Investigations at the Memorial SloanKettering CNRU focus on nutrition and its relationship to cancer, immunology, burns, pharmacology, and the brain as well as metabolism, diabetes, and lipids. To help find optimal ways to prevent and treat weight loss, cachexia, and other metabolism derangements that occur with cancer, CNRU researchers are examining whether riboflavin deficiency in experimental animals affects suppression of T-cells by syngeneic tumours.

Individual level

At the individual level, NCI is involved with cancer information dissemination programmes, which aim to influence the general public's dietary patterns. The NCl's goal is to reduce cancer mortality by 50 per cent by the year 2000. As part of its Cancer Prevention Awareness Program, the Office of Cancer Communication (OCC) is developing a national campaign to emphasize dietary changes which reduce an individual's risk of cancer. The OCC has designed publications and public service announcements promoting increased consumption of dietary fibre and decreased consumption of fat.

Uses of food composition data

As evident form the above discussion, NCI-supported researchers at the international, national, local, and individual levels vary in the sophistication of food composition data they would require. Scientists involved in international projects need a system with familiar names of foods, standard units of measurement, and foreign-language translations of data to understand better the relationship between nutrient intakes and cancer incidence patterns throughout the world. If associations between certain nutrient deficients (e.g. selenium) and cancer are confirmed, INFOODS could assist international agencies in identifying foods that must be imported to satisfy nutritional requirements and help prevent cancer.

National NCI-supported studies have a need for more standardized analysis techniques to permit intra-study comparisons, particularly with regard to fibre, carotenoid, and retinoid composition. Researchers would benefit from the standardization of sampling and analysis procedures, modes of data expression and conversion factors, and other guidelines developed by INFOODS. INFOODS vocabulary that would be particuiarly important include origin, part, process, and stage of maturity.

At the local level, access to a food data system would not only assist CNRU laboratory and clinical investigations, it would be useful in nutrition research training, nutritional support services, and the nutrition education activities of professionals, patients, and the general public. For example, medical and surgical residents or other professionals pursuing advanced nutrition training could be instructed about the INFOODS system and its standards and guidelines relating to data gathering, storage, interchange, and usage. The information could then be utilized in their research, which would ultimately contribute to the expansion of the INFOODS network.

At the individual level, consumers must be aware of the dietary modifications they can make to reduce their risk of cancer, the second leading cause of US mortality. The valid and reliable data managed by INFOODS ultimately could be used to guide the daily food choices of the American public.

Implications for infoods

What are the implications of this NCI-supported research for the development of INFOODS? First, to meet the needs of NCI-supported researchers, an internationally acceptable identification and classification scheme must be developed. The goal should be a non-hierarchical vocabulary, which is flexible and allows the future addition of other factors such as treatment or processes, level of maturity, and grade or quality descriptions. Second, any system must permit the user to describe exactly the type of printout or analysis needed. The NCI-support research projects illustrate the diversity of users of food composition data and the unique requirements of each study. While some researchers need complete tables with specialized information, others are focusing on the analysis of a single nutrient.

Finally, it is recommended that an attempt be made to anticipate the features that sophisticated statistical techniques will require. Statistical interpretation of data is, of necessity, an important function of any data system for all researchers, regardless of whether their focus is cancer, cardiovascular disease, diabetes, or another disease.

Summary

In summary, NCI supports various research projects, at the international, national, local, and individual levels, which depend on food composition data. Although the five levels of users vary in the sophistication of the information they require, all need access to a system of food data which is relatively simple to use and contains reliable data. Any system developed also must be sufficiently flexible to permit expansion or other modifications to accommodate new trends and needs. The internal structure of the data system should accommodate various statistical analyses and printout formats for researchers' unique study requirements. Such a system would promote international participation and co-operation and, in all probability, significantly improve research.

Food composition -a key to dietary appraisal and improvement in the United States

Introduction
Food composition data needs
National nutrition monitoring system
Nutrition education
Discussion
Approaches to meeting data needs
References

BElTY B. PETERKIN
Human Nutrition Information Service, US Department of Agriculture, Washington, D.C., USA

Introduction

The US Department of Agriculture (USDA) has traditionally been the primary provider of food composition data in the United States. Food composition data are vital to the major responsibilities of the Department: (a) to ensure that an adequate, wholesome, and nutritious supply of food is available and (b) to provide information to help Americans select good diets [21]. USDA food composition data are also used extensively by the Department of Health and Human Services (DHHS) - the agency with responsibility for studies of diet and disease and for the nutrition-labelling programme.

USDA contributes to food and agricultural progress throughout the world. This activity and its role as the provider of US food composition data explain USDA's support of INFOODS and earlier efforts to help make food composition data available in various regions of the world.

A wide range of activities helps to fulfil USDA's mission as it relates to nutrition. Research, information, education, regulatory, and food assistance programmes are examples [6]. Each requires food composition data. This paper describes some of these activities and their food composition data needs, and outlines the means by which USDA's Human Nutrition Information Service (HNIS) attempts to meet these needs (see chap. 11).

Food composition data needs

Human Nutrition Requirements Research

USDA's Agricultural Research Service (ARS), in its five Human Nutrition Research Centers, helps to define the amounts of nutrients and other dietary substances that promote optimum growth, development, and nutritional health. ARS scientists also study factors affecting the absorption of nutrients in the body. These studies, of course, require a precise understanding of the nutrient content of the diet. Many studies analyse diets for nutrient content; others calculate the nutrient content of diets using food composition tables. The individual centres focus on different research areas. For example, the centre at Tufts University in Boston studies the nutrition factors affecting the aging process, and the one in Houston at the Baylor College of Medicine studies the nutrition of infants and children. One of the research areas of the Human Nutrition Research Center at Beltsville, Maryland? is the development of methods for determining the composition of foods (see chap. 18).

Additional research on human nutrition requirements and the nutrient content of foods and diets is conducted at 58 state agricultural experiment stations. The Cooperative State Research Service serves as a link with the state system. Major research on food components as they relate to various diseases is conducted in another federal agency, the National Institute of Health (NIH), and by means of grants from NIH. While some of these studies include analyses of foods, others use USDA's standard reference tables adapted and extended to meet their own special needs.

Meat and Poultry Products Regulations

The Food Safety and Inspection Service (FSIS) safeguards the wholesomeness and nutritional quality of meat, poultry, and their products through inspection and analyses. This agency establishes standards, approves labels for meat and poultry products, and monitors the industry for compliance with inspection laws. As well as analysing the nutritional value of meat and poultry products, both domestic and imported, and determining the presence of food additives, it also assesses the nutritional equivalency of imitation and traditional foods and the effects of processing procedures on nutritional quality. For these varied purposes, FSIS conducts laboratory analyses and uses standard reference tables. The Food and Drug Administration (FDA) of the Department of Health and Human Services performs similar regulatory functions for foods other than meat and poultry.

Food Assistance Programmes

The Food and Nutrition Service (FNS) operates 10 major food assistance programmes. Through these programmes, populations at nutritional risk receive food or resources with which to obtain food. Some, such as the Food Stamp Program, provide assistance to the low-income population. Others are designed to help meet the nutritional needs of particular groups, such as children in school and in child care; pregnant and postpartum women, infants, and young children (WIC); and elderly persons. Studies of the effects of programmes on the diets of participants require food composition data, as does the development of standards for programme benefits and compliance.

The legal standard for benefits from the Food Stamp Program is the cost of foods in the thrifty food plan - the least costly of four food plans for nutritious diets developed and costed monthly by HNIS [12]. These food plans reflect food consumption and nutrient levels as reported in the Nationwide Food Consumption Surveys (NFCS), changed only as necessary to meet nutritional goals for 17 food substances. The quantities of foods in the food plans are specified with the assistance of a computerized mathematical model.

Meal patterns for the school lunch and breakfast programmes are designed with the nutrient content of foods they contain as a major consideration. An alternative to using meal patterns as the basis for compliance in the school lunch programme is being field-tested; this involves instead the use of a nutrient standard for the lunch. HNIS has co-operated with FNS in developing software and special data bases for this test. Another programme, WIC, distributes vouchers for foods with nutrient content that will supplement the diets of participants.

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