the sequence of the entire human genome was completed in 2003, just 50 years after the description of the double-helical nature of DNA by Watson and Crick

late 1990s in sequencing the human genome led in the mid-2000s to the announcement that over 90% of the genome had been sequenced

Apart from infectious organisms and environmental pollutants, many diseases are manifestations of abnormalities in genes, proteins, chemical reactions, or biochemical processes, each of which can adversely affect one or more critical biochemical functions

Recent increasing emphasis on systematic attempts to maintain health and forestall disease, or preventive medicine, includes nutritional approaches to the prevention of diseases such as atherosclerosis and cancer.

The maintenance of health requires optimal dietary intake of vitamins, certain amino acids and fatty acids, various minerals, and water.

The World Health Organization (WHO) defines health as a state of “complete physical, mental, and social well-being and not merely the absence of disease and infirmity.”