Challenges for public health nutrition in the 1990s.

Abstract

A scientific approach to public health nutrition includes: collection of evidence regarding the relation of nutritional factors to health and disease; assessment of current dietary practices; development of strategies to modify diets in a manner deemed to be beneficial; and the evaluation of intervention strategies. This approach has been successful in eliminating several nutritional deficiencies that were once widespread. Despite these successes, nutritional factors remain as probable major determinants of the dominant health problems, particularly cardiovascular diseases and cancer, in the United States and other affluent countries. As we enter a new decade, a consideration of challenges facing those working to improve our nation's health through nutrition may be appropriate. The Scientific EvidenceEstablishing the relation between nutrition and chronic diseases such as cancer and cardiovascular diseases has been more elusive than for deficiency-related diseases such as pellagra and rickets. Unlike specific vitamin deficiencies, the common chronic diseases almost always have multiple causes, including interactions with genetic factors. Also, chronic diseases often have long latent periods, perhaps resulting from many years of continuous exposure, and occur with relatively low frequency even though the cumulative lifetime risk is high. Thus, it is a formidable challenge to obtain a high level of proof that a particular nutritional factor is a cause of disease.Several large, official reviews during the last 10 yearsl-3 have examined the relationship of diet and nutrition to health and disease. This information cannot be considered in detail in an editorial; however, several general comments can be made regarding coronary heart disease and cancer. Coronary Heart DiseaseDespite the prominence given to the relation between diet and coronary heart disease (CHD) during the last 40 years, direct evidence is disappointingly meager. Very few human studies, either case-control or cohort observational studies or intervention trials, have directly examined the relationships between dietary factors and cardiovascular disease. Almost all were seriously limited in size or by their method of dietary assessments.4 Only two consistent findings have emerged:* an inverse relation between energy intake and the risk of coronary heart disease (almost surely reflecting the protective effects of physical activity), and * a strong protective effect of moderate alcohol intake. Although the focus ofdietary recommendations is usually a reduction in saturated fat intake, no relation between saturated fat intake and risk of CHD was observed in the most informative prospective study to date.5 Even if such a relationship exists, the widely quoted ecological association found by Keys6 was probably fortuitously confounded, because the magnitude of the relationship between saturated fat intake and CHD rates was considerably stronger than expected on the basis of metabolic studies of diet and blood lipids and, in turn, epidemiologic studies of ser...

Nutrient intakes of an adult Pakistani, European and African‐Caribbean community in inner city Britain

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Usual diet in Bubis, a rural immigrant population of African origin in Madrid

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