Nutritional epidemiology:
(Understanding the diet-disease relationship.)
Dr. AbhishekMagotra1 Dr. Shivakumar2
1-. PG Scholar, Dept of Swasthavritta ,SDM College of Ayurveda and Hospital Hassan.
2- Associate Professor and HOD Dept ofSwasthavritta SDM College of Ayurveda and Hospital Hassan.
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Abstract
Epidemiology is the study of the distribution and determinants of health -related states or events in specified population, and the application of this study to the control of health problems. Nutritional epidemiology is a sub discipline of epidemiology and provides specific knowledge to nutritional science. It provides data about the diet-disease relationships that is transformed by Public Health Nutrition into the practice of prevention. Over the past couple of decades, a large number of observational studies have attempted to elucidate the role of diet in health and disease.Nutritional epidemiology has several goals. Perhaps themost basic is monitoring the food consumption, nutrient intake and nutritional status of a population.Ultimately, the overall goal of nutritional epidemiology is to contribute to the prevention of disease and the improvement of public health. key advantage of nutritional epidemiology is its direct relevance to human health. Epidemiologists study reallife. They do not need to extrapolate from animal models or in vitrosystems.The most important disadvantage of nutritional epidemiology is the potential for many kinds of bias.Nutritional epidemiology studies can generate information of great relevance to public health.If nutritional epidemiology research is misinterpreted by the lay public or by scientists not trained in epidemiology, it may do more harm than good.
So there is great need to understand the concept, methods, uses and practical approaches of Nutritional epidemiology in order to play a important role in prevention of disease.
Key Words: Epidemiology ,Nutritional epidemiology, Diet ,Health, Disease.
Introduction
Nutritional epidemiology is a relatively new field of medical research that studies the relationship between nutrition and health. Diet and physical activity are difficult to measure accurately, which may partly explain why nutrition has received less attention than other risk factors for disease inepidemiology1. Nutritional epidemiology is a sub discipline of epidemiology and provides specific knowledge to nutritional science. It provides data about the diet-disease relationships that is transformed by Public Health Nutrition into the practice of prevention. The specific contributions of nutritional epidemiology include dietary assessment, description of nutritional exposure and statistical modeling of the diet-disease relationship.Over the past couple of decades, a large number of observational studies have attempted to elucidate the role of diet in health and disease.Nutritional epidemiology is one of the younger disciplines in epidemiology. This may be partially due to the difficulties in measuring diet as an exposure. Diet and physical activity are arguably the most difficult exposures to assess in observational research and are plagued by considerable measurement error. We all eat, we all eat many different foods, we tend to forget rather quickly what we ate, and we often do not know the ingredients of the dishes we consume. Hence we are all exposed, and the variation may be more subtle than with other, more distinct exposures such as smoking or use of hormone replacement therapy. Few people maintain extreme diets; thus assessing diet within fairly homogeneous populations makes it difficult to detect associations between dietary patterns (or particular foods and nutrients) and health or disease due to the lack of sufficient variation
Some milestones in nutritional epidemiology
The field is often dated to 1753, when Lind observed that fresh fruits and vegetables could cure scurvy and conducted one of the earliest clinical trials with lemons and oranges, which, he noted, had "most sudden and good effects" in treating the disease. Much later, it was found that vitamin C deficiency was the cause. KanehiroTakaki in 1884 links Japanese sailors' diet of polished rice to the disease beriberi. He adds milk and vegetables to their diet and eliminates the disease. Much later, in 1933, Robert R. Williams named the key nutrient, (vitamin B1), completing research begun by Japanese J. Suzuki and colleagues in 1912.
First practical work
The first population-based studies collecting information on nutrition were conducted in the 20th century. Data on only a few foods were collected generally and were cross-classified with disease outcomes. More detailed dietary assessment instruments were subsequently developed, the most popular of which are the 24-hour recall, a food diary kept for several days, and the food frequency questionnaire
Goals of nutritional epidemiology
Nutritional epidemiology has several goals. Perhaps themost basic is monitoring the food consumption, nutrient intake and nutritional status of a population. Other key goals are to generate new hypotheses about diet and disease, to produce evidence that supports or
refutes existing hypotheses and to assess the strength of diet-disease associations. Ultimately, the overall goal of nutritional epidemiology is to contribute to the prevention of disease and the improvement of public health.
Methods of Dietary Assessment
Two primary classes of methods have been used historically to assemble individual
dietary information and synthesize it into something usable in data analysis, described in detail by Willett 2. The first method includes dietary recalls andrecords. Dietary recalls are obtained by an interviewer assisting the participant toremember precisely what was eaten, usually over the past 24 h.The second method is a food frequency questionnaire (FFQ), characterized by
asking the participant general questions about diet.
Advantages
key advantage of nutritional epidemiology is its direct relevance to human health. Epidemiologists study reallife. They do not need to extrapolate from animal models or in vitrosystems. The results of their work are often used to calculate direct estimates of risk, which can then be translated into specific recommendations for changes in nutrient intakes or food consumption patterns.
Disadvantages
The most important disadvantage of nutritional epidemiology is the potential for many kinds of bias. Bias is defined as systematic error, resulting in underestimation of the strength of an association between an exposure and an outcome. The apparent simplicity and “real life” relevance of epidemiological findings may also be a disadvantage in some circumstances because they encourage the misuse and over interpretation of data. This is especially true when preliminary or unconfirmed findings come to the attention of the news media and the general public.
Summary
Nutritional epidemiology is the study of the nutritionaldeterminants of disease in human populations. It is anexciting branch of epidemiological research because itcan provide insight into the causation and prevention ofmany of today's most crucial health problems, includingthe chronic diseases of aging. However, it is a very difficult field of research because the exposures of interest – dietary intakes – are extremely complex.Nutritional epidemiology studies can generate information of great relevance to public health.If nutritional epidemiologyresearch is misinterpreted by the lay public or by scientists not trained in epidemiology, it may do more harm than good. However, if it is applied in appropriate ways, nutritional epidemiology can be of great value to public health authorities, health care professionals and the food industrial. All of these groups can apply the findings of nutritional epidemiology in ways that can contribute to current efforts to improve health through disease prevention
References
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