History and recent developments
This new science has rapidly expanded. Vitamins were first written about in 1912, by Sir Frederick Gowland Hopkins, who was knighted and received the Nobel Prize in 1929 for his achievements.
In the 20th century, after clarification of the nature and role of proteins, carbohydrates, vitamins and minerals, it was thought that we had adequate knowledge about the elements of food. Food was seen as the fuel, and we simply had to have enough of its ingredients in order to go on living. However, there followed an accelerating series of discoveries starting with fibre, which has revealed increasingly large gaps in our knowledge about the role of food in our health and proper functioning.
We now know that there are many thousands of phytochemicals in our food, each of them performing an essential role in the proper functioning of our bodies. Furthermore, it is thought that there are many more phytochemicals and other components of food to be discovered. There are also enzymes which play an important part in nutrition: these are chemical catalysts in our food and also produced in our digestive system. They are vitally important in all the metabolic activity in our bodies.
Antioxidants are another recent discovery. Using energy in our bodies often has damaging side effects on cells, and certain food elements such as vitamin E have been seen to be vital in protecting against the aging effect of this oxidizing damage.
The balance of essential fatty acids (linoleic and linolenic oil) has been discovered to be crucial in maintaining good health. This involves omega 3 and omega 6 oils, as well as the need to minimise saturated and hydrogenated fats in our diet.
Phytoestrogens have been shown to play another essential role in supporting the body’s hormonal and other metabolic activities.
The previous mechanistic view of food as fuel, and the simplistic notion that protein, carbohydrate etc. were each obtained from one type of food (the meat and two veg model) has all but been replaced.
It is now also known that the human digestion system contains a population of a range of bacteria which are essential to digestion, and which are also affected by the food we eat.
This increasing complexity has led to nutrition researchers today advocating a holistic approach. They readily admit that there are many nutrients and other factors we don't know enough about, and that most foods contain most types of nutrients in various proportion. Provided excess is avoided, particularly of carbohydrates and saturated fats, then it has been shown that our needs are best met through eating a wide variety of fresh, unprocessed and unmanufactured food.
The Institute for Food Additives and Ingredients gives the following information:
- "Far more is now known about the science of nutrition than ever before and the overriding message is that a very broad diet, taking in vital categories of essential nutrients, is better than a narrowly focussed diet, even if that diet sets out to avoid dangerous foodstuffs such as saturated fats.
- A survey has shown that the Japanese tend to eat a greater variety of different foods every day than Westerners (27 different foods a day whereas the recommended minimum in the West is 30 different foods per week); they are less prone to the 'diseases of civilization' - diabetes, heart disease and cancer - than Europeans, and their varied diet is thought to contribute to this."
Nutrition and health
In the 18th Century, many sailors on long journeys died from scurvy: indeed some battleships lost more men through illness than through enemy action. The cause of this was not understood, until it was discovered that adding fresh limes to the ship’s supply of preserved food seemed to boost the sailor’s resistance to the illness, and few died. The existence of parts of food essential for survival had been discovered. Other so-called vitamins were discovered through the effect of their absence on people’s health, and increasingly the role of nutrition’s contribution to health was seen as equally important as exercise, hygiene, environment, and psychological wellbeing.
The connection between nutrition and health has weakened however. Good health became the norm in the developed world through increased understanding of communicable diseases, micro-organisms and how to fight them with antibiotics, and other health developments. A hidden epidemic gradually emerged in the post World War 2 years, where non-communicable endemic illnesses began to flourish, such as heart disease, cancer, diabetes and obesity.
These illnesses are increasingly recognised now as being sometimes caused by lifestyle issues, including poor nutrition and low levels of exercise. Despite this knowledge, the peak of the epidemic is still with us, and obesity related diseases are prevalent in the developed world.
Many nutritionists ascribe this to excess carbohydrates, decreasing levels of exercise, fewer vegetables and fruit and the wrong type of fats in our diet. Others feel that governments and the food industry has not yet recognised or acted upon this insight. Fast food restaurants are spreading around the world, and Westernisation has unfortunately brought the "diseases of civilisation" with it. A reaction to this has been the development of a slow food trend. This has now got its own University, at the University of Pollenzo in Piedmont Italy whose goal is to promote awareness of good food and health through nutrition.
Nutrition research has identified many components of good nutrition, so that in general a wide variety of unprocessed food is recommended as a natural preventive measure, to maintain good health rather than individual foods as remedies for perceived deficiencies.
Nutrition can affect health in many ways. Ill-health can be brought about by an imbalance of nutrients, producing either an excess or deficiency which in turn affects body functioning in a cumulative manner. The body can be affected at the micro or macro levels by nutrition, for example cancer can arise through cell metabolism malfunction, and high energy levels can promote health through frequent activity.
Some examples are :
- Obesity results in fatty deposits in the abdomen which in turn affect the efficiency of the liver, heart, gall bladder, circulation etcetera. (See Janssen I, et al,. 2004)
- The wrong kinds of fats can cause the build-up of cholesterol-related plaque on artery walls which can eventually result in a blockage or poor blood supply to other organs, e.g. the brain or the heart itself, indirectly therefore causing angina, heart failure, brain disfunctioning, CVAs etc..
- An excess of complex carbohydrates and/or sugars can lead to imbalances in insulin production. This in turn can lead to fatigue, chronic tiredness, diabetes, and obestity through overeating.
- Mineral or vitamin deficiencies are thought to be responsible for many illnesses, including goitre, scurvy, osteoporosis, poor immune system response (and indirectly some forms of cancers), disorders of cell metabolism, premature ageing etc., poor psychological health, including eating disorders.
- Imbalances in omega 3 and omega 6 fatty acids is thought to be related to autism and some attention disorders [1], and bipolar disorder (See Sobczak S, et al 2994, and the Times newspaper February 28, 2004 Autism: I can see clearly now . . . by Simon Crompton).
- Intolerance of gluten ( a protein in wheat and rye) is suspected of being related to the development of schizophrenia in some cases. (See British Medical Journal, February 21, 2004.)
- Alzheimer's disease may be linked to B vitamin deficiencies. (See the Times newspaper, January 31 2004 "Could vitamins help delay the onset of Alzheimer’s?" by Jerome Burne).
Food processing
Food can be made safer and more palatable through processing. Food processing therefore has a valuable role in contributing to good nutrition. However, some nutritionists advise caution.
Food processing is sometimes seen as adversely affecting people’s health: polished rice was identified as a cause of beri-beri when people realized that removing the skin of the rice was a process which removed essential nutrients.
In the late 1800s in the United States, babies started developing scurvy; there was a veritable plague. It turned out that the vast majority of sufferers were being fed milk that had been heat treated (as suggested by Pasteur) to control bacterial disease. Pasteurization was effective against bacteria, but it destroyed the vitamin C, causing a nutritional disease.
Other examples of adverse effects of food processing, together with research findings and the need to be cautious in the light of our limited and incomplete knowledge, have called food processing into question.
Today's leading nutritionists advise against the processing of food where possible, since undiscovered but possibly essential nutrients may be thereby removed, or toxins may be added or produced through processing and high temperature cooking. Also processing can replace some of the mechanical/biochemical body processes which are essential for full digestion, and hence good nutrition. For example, the cooking of foods may destroy enzymes which are thought by some to be necessary for proper digestion.
Cornell nutritional biochemist T. Colin Campbell, Professor and director of the China project stated at a symposium on epidemiology:
- "Analyses of data from the China studies ... is leading to policy recommendations." He mentioned three:
- "The greater the variety of plant-based foods in the diet, the greater the benefit. Variety insures broader coverage of known and unknown nutrient needs.
- Provided there is plant food variety, quality and quantity, a healthful and nutritionally complete diet can be attained without animal-based food.
- The closer the food is to its native state -- with minimal heating, salting and processing -- the greater will be the benefit."(Cornell Chronicle 28/6/01)[1]
