Original post: July 25, 2010
Throughout the 20th century, nutritional science focused on finding vitamins and minerals, defining their use and preventing the deficiency diseases that they caused. As the nutrition related health problems of the developed world shifted to overnutrition, obesity and type two diabetes, the focus of modern medicine and of nutritional science changed accordingly.
In order to address the increasing incidence of these diet-related-diseases, the role of diet and nutrition has been and continues to be extensively studied. To prevent the development of disease, nutrition research is investigating how nutrition can optimize and maintain cellular, tissue, organ and whole body homeostasis. This requires understanding how nutrients act at the molecular level. This involves a multitude of nutrient-related interactions at the gene, protein and metabolic levels. As a result, nutrition research has shifted from epidemiology and physiology to molecular biology and geneticsand nutrigenomics was born.
The emergence and development of nutrigenomics has been possible due to powerful developments in genetic research. Inter-individual differences in genetics, or genetic variability, which have an effect on metabolism and on phenotypes were recognized early in nutrition research, and such phenotypes were described. With the progress in genetics, biochemical disorders with a high nutritional relevance were linked to a genetic origin. Genetic disorders which cause pathological effects were described. Such genetic disorders include the polymorphism in the gene for the hormone Leptin which results in gross obesity. Other gene polymorphisms were described with consequences for human nutrition. The folate metabolism is a good example, where a common polymorphism exists for the gene that encodes the methylene-tetrahydro-folate reductase (MTHFR).
It was realized however, that there are possibly thousands of other gene polymorphisms which may result in minor deviations in nutritional biochemistry, where only marginal or additive effects would result from these deviations. The tools to study the physiological impact were not available at the time and are only now becoming available enabling the development of nutrigenomics. Such tools include those that measure the transcriptome – DNA microarray, Exon array, Tiling arrays, single nucleotide polymorphism arrays and genotyping. Tools that measure the proteome are less developed. These include methods based on gel electrophoresis, chromatography and mass spectrometry. Finally the tools that measure the metabolome are also less developed and include methods based on nuclear magnetic resonance imaging and mass spectrometry often in combination with gas and liquid chromatography.