NUTRITIONAL BIOCHEMISTRY

NUTRITIONAL BIOCHEMISTRY. Nutritional biochemistry is one of the academic foundations that make up nutritional sciences, a discipline that encompasses the knowledge of nutrients and other food components with emphasis on their range of function and influence on mammalian physiology, health, and behavior. Nutritional biochemistry is a subdiscipline that is made up of the core knowledge, concepts, and methodology related to the chemical properties of nutrients and other dietary constituents and to their biochemical, metabolic, physiological, and epigenetic functions. A primary focus of research in nutritional biochemistry is the scientific establishment of optimal dietary intakes (Dietary Reference Intakes or DRIs) for every nutrient and food component throughout the life cycle (Thomas and Earl, 1994; Standing Committee, 1998).

Nutritional biochemistry is an integrative science whose foundation is derived from knowledge of other biological, chemical, and physical sciences, but it is distinguished in its application of this knowledge to understanding the interactive relationships among diet, health, and disease susceptibility. For example, nutritional bio-chemistry is rooted in analytical methodology that permits the purification of individual nutrients and the determination of their structures, as well as in classical biochemical approaches that identify metabolic pathways and elucidate the role of dietary components in regulating metabolism and gene expression. Additionally, human genetic studies of inherited inborn errors of metabolism, such as phenylketonuria, have contributed to core nutritional biochemical knowledge by revealing important interrelationships among nutrition, metabolism, and genotype and their interactions during normal and abnormal human development.

Knowledge generated from nutritional biochemistry research forms the foundation upon which nutrition-based public health interventions are designed and implemented. Many common diseases and disabilities afflicting human populations in both developing and developed countries result from general malnutrition, deficiencies of specific nutrients, or overnutrition. Inadequate diets or poor dietary habits are associated with increased risk for morbidity and mortality, including birth defects, diabetes, cardiovascular disease, obesity, and certain cancers. Specific nutrients, food components, or metabolites, singularly or in combination, can contribute to risk for disease or, alternatively, can be protective by preventing disease. Furthermore, associations among dietary components and diseases are strongly influenced by subtle genetic variation, such as single nucleotide polymorphisms, which are prevalent in all human populations. Research-based diet therapies and strategies to decrease the incidence of nutrition-related diseases have a successful history of improving public health and individual quality of life. Such strategies include (1) the fortification of grain products with folic acid to decrease the incidence of common birth defects (spina bifida), (2) the iodinization of table salt to prevent cretinism, a developmental disorder associated with severe neurological and cognitive deficits in children, and (3) the promotion of diets low in cholesterol to prevent and to manage cardiovascular disease. These nutrition-based interventions have impacted the quality of life for individuals, and the monetary effects associated with the amelioration of these disorders have significantly benefited health care systems and national economies.

Current research and discovery in nutritional biochemistry is focused broadly in several areas, including nutritional genomics and metabolomics. Nutritional genomics is the study of genome–nutrient interactions and includes (1) the role of nutrients and dietary components in regulating genome structure, expression, and stability, and (2) the role of genetic variation on individual nutrient requirements. Nutritional metabolomics is the study of metabolic pathways and networks and includes (1) the regulation of metabolic pathways and networks, by nutrients and other food components, and (2) the establishment of analytical methods that "profile" human serum and urinary metabolites to assess nutritional imbalances and disease risk. It is anticipated that knowledge derived from these new approaches will enable nutrient requirements to be tailored to an individual's genetic profile for optimal health throughout the life cycle. In addition, information obtained from these new technologies will inform efforts (1) to improve or to enhance the food supply through the targeted introduction of traditional or novel foods, (2) to fortify food chemically with specific nutrients, or (3) to enhance crops genetically for higher nutrient content or quality.

Nutritional sciences academic training programs with a strong emphasis in nutritional biochemistry reside in medical colleges (e.g., Columbia University), schools of public health (e.g., Harvard University), and land grant universities (e.g., Cornell University). Nutritional sciences training programs can be independent units, jointly administered or affiliated with programs of toxicology, biochemistry, animal sciences, food sciences, and various medical programs. Academic faculty in nutritional biochemistry can be expert in many disciplines, including chemistry, biochemistry, genetics, and physiology. Therefore, individual nutritional sciences programs with distinct nutritional biochemistry concentrations are highly unique. Nutritional biochemists establish careers in teaching and research within universities, governmental and regulatory agencies, and the food, pharmaceutical, or biotechnology industries. Nutritional biochemists may also work in fields related to public policy, health care, or product development and marketing in the food industry.

See also Dietary Guidelines; Nutraceuticals; Nutrient Bioavailability; Nutrients.

BIBLIOGRAPHY

Allen, Lindsay H., Margaret E. Bentley, Sharon M. Donovan, Denise M. Ney, and Patrick J. Stover. "Securing the Future of Nutritional Sciences through Integrative Graduate Education." Journal of Nutrition 132 (2002): 779–784.

Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, D.C.: National Academy Press, 1998.

Thomas, Paul R., and Robert Earl, eds. Opportunities in the Nutrition and Food Sciences. Washington, D.C.: National Academy Press, 1994.

Patrick J. Stover

Core Knowledge that Defines Nutritional Biochemistry

• Structure and function of nutrients and other dietary constituents
• Chemical structure and metabolic functions of essential and nonessential nutrients
• Physiological and biochemical basis for nutrient requirements
• Motifs of absorption and transport of nutrients
• Integration, coordination, and regulation of macro-and micronutrient metabolism
• Regulation of nutrient metabolism and nutritional needs by hormones and growth factors
• Interaction of nutrients with the genome; nutrient control of gene expression; DNA stability
• Dietary bioactive components (functional foods)—nontraditional roles of nutrients
• Food, diets, and supplements
• Food sources of nutrients and factors affecting nutrient bioavailability
• Effect of food processing and handling on nutrient content and bioavailability
• Nutritional toxicology—upper limits of intake; nutrient–nutrient and drug–nutrient interactions
• Dietary Reference Intakes (DRIs); Food Guide Pyramid
• Nutrient supplements—risks/benefits, life stage, bioavailability
• Molecular markers of nutrient intake—gene arrays and analytical chips
• Nutrition and disease
• Impact of disease and genetics on nutrient function and requirements
• Genetic basis of inherited metabolic disease

SOURCE: Allen, Lindsay H., Margaret E. Bentley, Sharon M. Donovan, Denise M. Ney, and Patrick J. Stover, "Securing the Future of Nutritional Sciences through Integrative Graduate Education." Journal of Nutrition 132 (2002): 779–784.