Nutrition milestones: the development of nutrition as a science
Throughout human existence people have attributed special powers to certain foods and developed beliefs and taboos regarding foods. These were often based on climatic, economic, political, or religious circum-stances and principles, but also on observations regarding the relationship between the consumption of certain foods and health.
Recorded examples are ancient Chinese and Indian philosophers who advised on the use of warming and cooling foods and spices for certain conditions and for “uplifting the soul,” the Mosaic laws documented in the Old Testament which distinguished between clean and unclean foods, the fasting and halal prac-tices of Islam, and the Benedictine monks from Salerno who preached the use of hot and moist versus cold and dry foods for various purposes. Hippocrates, the father of modern medicine, who lived from 460 to about 377 BC, and later Moses Maimonides, who lived in the twelfth century, urged people to practice abstemiousness and a prudent lifestyle. They, and others, advised that, for a long and healthy life, one should avoid too much fat in the diet, eat more fruit, get ample sleep, and be physically active – advice that is still incorporated in the modern, science-based dietary guidelines of the twenty-first century!
The perception that food represents more than its constituent parts is still true. Eating together is an accepted form of social interaction. It is a way in which cultural habits and customs, social status, kinship, love, respect, sharing, and hospitality are expressed. Scientists and nutrition professionals realize that, when formulating dietary guidelines for traditional living people, cultural beliefs and taboos should be taken into account and incorporated. There are numerous examples of traditional food habits and diets, often based on what was available. Today, with the world becoming a global village, cultures have learned from each other, and dietary patterns associ-ated with good health, such as the Mediterranean diet, are becoming popular among many cultures.
The knowledge of the specific health effects of par-ticular diets, foods, and nutrients is now firmly based on the results of rigid scientific experimentation. Nutrition developed gradually as a science, but advanced with rapid strides during the twentieth century. There are numerous meticulously recorded examples of how initial (often ancient and primitive) observations about diet and health relationships led to the discovery, elucidation of function, isolation, and synthesis of the different nutrients. Perhaps the most often quoted example is James Lind’s descrip-tion in 1772 of how citrus fruit could cure and prevent scurvy in seamen on long voyages. The anti-scurvy factor (ascorbic acid or vitamin C) was only isolated in 1921, characterized in 1932, and chemically syn-thesized in 1933. Other examples of nutritional mile-stones are the induction of beriberi in domestic fowl by Eijkman in 1897, the observation of Takaki in 1906 that beriberi in Japanese sailors could be prevented by supplementing their polished rice diets with wheat bread, and, eventually, the isolation of the responsible factor, thiamine or vitamin B1, by Funk in 1911. Others are the Nobel Prize-winning discovery by Minot and Murphy in 1926 that pernicious anemia is a nutritional disorder due to a lack of vitamin B12 in the diet, the description of kwashiorkor as a protein-deficiency state by Cecily Williams in 1935, and the discovery of resistant starch and importance of colonic fermentation for humans by nutritionists of the Dunn Clinical Nutrition Centre in the 1980s.
The history of modern nutrition as practiced today is an exciting one to read, and students are encour-aged to spend some time on it. It is often character-ized by heartbreaking courage and surprising insights. An example of the former is the carefully documented clinical, metabolic, and pathological consequences of hunger and starvation by a group of Jewish doctors in 1940 in the Warsaw ghetto: doctors who them-selves were dying of hunger. An example of the latter is the studies by Price, an American dentist, who tried to identify the dietary factors responsible for good dental and overall health in people living traditional lifestyles. He unwittingly used a fortigenic paradigm in his research, examining the strengths and factors that keep people healthy, long before the term was defined or its value recognized.
At present, thousands of nutrition scientists examine many aspects of nutrition in laboratories and field studies all over the world and publish in more than 100 international scientific nutrition jour-nals. This means that nutrition science generates new knowledge based on well-established research meth-odologies. The many types of experiments, varying from molecular experimentation in the laboratory, through placebo-controlled, double-blinded clinical interventions, to observational epidemiological sur-veys, and experiments based on a health (fortigenic) or a disease (pathogenic) paradigm, will be addressed in this volume. The peer-review process of published results has helped in the development of guidelines to judge how possible, probable, convincing, and applicable results from these studies are. New knowledge of nutrients, foods, and diet relationships with health and disease is, therefore, generated through a process in which many scientists examine different pieces of the puzzle all over the world in controlled scientific experiments. Therefore, nutrition practice today has a firm research base that enables nutritional professionals to practice evidence-based nutrition.
There is little doubt that improved nutrition has con-tributed to the improved health and survival times experienced by modern humans. However, global figures on the prevalence of both undernutrition and overnutrition show that millions of people do not have enough to eat, while the millions who eat too much suffer from the consequences of obesity. It is tempting to equate this situation to the gap between the poor and the rich or between developing and developed countries, but the situation is much more complex. Obesity, a consequence of overnutrition, is now a public health problem not only in rich, devel-oped, food-secure countries but also in developing, food-insecure countries, especially among women. Undernutrition, the major impediment to national development, is the biggest single contributor to childhood death rates, and to impaired physical growth and mental development of children in both developing and developed countries. Moreover, a combination of undernutrition and overnutrition in the same communities, in single households, and even in the same individual is often reported. Examples are obese mothers with undernourished children and obese women with certain micronutri-ent deficiencies. The perception that these global problems of malnutrition will be solved only in inno-vative, multidisciplinary, and multisectorial ways has led to the second, very recent renaissance in nutrition research and practice.