The Importance of Nutrition for Human Health

from The Science of Supplementation of USANA

The importance of nutrition for human health has long been recognized. Prior to 1960, interest in this field focused primarily on the etiology and prevention of acute nutrient deficiency diseases, such as scurvy, rickets, and pellagra. Some 50 essential nutrients (vitamins, minerals, antioxidants, cofactors, essential amino acids, essential fatty acids) were identified, and recommended daily intakes for those essential nutrients were developed. These recommendations, in turn, proved valuable in eradicating acute nutrient deficiency diseases. 

During the past 20 years, attention has shifted to the role of diet and nutrition in the pathogenesis of chronic degenerative diseases. Heart disease, some cancers, osteoporosis, type II diabetes, and macular degeneration are well-known examples of diseases with dietary risk factors, and research is currently underway on many more nutrient-disease interactions. Unfortunately, these associations are difficult to study, in part because of the time frames involved. Chronic degenerative diseases develop over decades (or lifetimes), and it is extremely difficult to conduct research programs spanning more than several years in length. Nevertheless, advances in epidemiological and clinical research have uncovered a great deal of information about the impact of diet and nutrient intakes on long-term health. 

USANA's "Health Benefits of Nutritional Supplements" document is an enumerative bibliography of peer-reviewed research examining possible health benefits of nutritional supplements and functional foods. Papers have been selected on the basis of scientific merit and relevance to the field, regardless of whether positive or negative results were obtained. Our objective in compiling this list is to provide readers with a good cross-section of recent scientific literature, with hopes of contributing to a better understanding of the current state of nutritional research.