Health > Food And Diet >Trace Elements
In the human body - that wonder of complex chemistry - trace elements play vital roles. But too much of them, as well as too little, can cause illness.
A balanced diet includes protein, starch, fat and also the vitamins and minerals that we need us healthy. Some minerals are required in such tiny amounts that they are called the ‘trace elements’ as only a tiny trace of them is needed.
In terms of quantity most of our needs are catered for by the three elements carbon, oxygen and hydrogen, and to a lesser extent nitrogen: we take in kilograms of these substances every day. Relatively large amounts of other elements such as sodium, potassium and calcium are also required, and we normally take in a few grams of these every day. However, trace elements such as copper, fluorine and iodine, which are just as essential for normal life, are needed only in minute quantities. For example, we only need a few thousandths of a gram of copper and even less of such elements as iodine and chromium. The body relies on remarkably few elements to set up that complex and intricate web of chemical reaction that keeps us alive and healthy.
WHAT THEY DO ?
Most important trace elements have a role in bringing about the activity of the body’s various enzymes. Their function is to assist in chemical reactions in the body, and although they set a process going they remain unchanged at the end of the reaction. This means they act as catalysts.
All the enzymes are proteins, and what each one does depends on the shape into which the long string like protein molecule winds itself. Trace elements play a role because it seems that a few of the body’s enzymes require strong chemical forces - produced by atoms of certain metallic elements - to attain the correct shape for action. Therefore, most of the trace elements we need are metallic and they either from part of the structure of an enzyme, or they take part in its chemical reaction in the body.
Also, a few trace elements seem to be part of the structure of other important substances in the body. Fluorine is associated with the structure of bones and teeth, and iodine is an essential constituent of the thyroid hormones.
HARMFUL TRACE ELEMENTS
Traces of some substances, often present in food or air, are not only of no value, but can be positively dangerous. Metals such as lead, mercury and arsenic are all poisonous in sufficient quantities and have absolutely no use within the body.
Apart from the purely poisonous metals, it is possible to accumulate high levels of normally beneficial, essential trace elements that can then cause illness. In haemachromatosis, an abnormality of the transport of iron in the blood leads to an accumulation of iron in the blood leads to an accumulation of iron in the liver and pancreas. This can cause cirrhosis and diabetes. A genetic linked disease - called Wilson’s disease - also occurs. The copper metabolism becomes disorganized and this leads to accumulations of copper in the heart and liver.
In other circumstances accidental intake leads to poisoning by metals that are essential only in very small amounts. The most notorious example of accidental excess was in Quebec, Canada, where cobalt was added to beer to improve the froth, and therefore put a better head on a glass of beer. This led to an outbreak of heart failure in beer drinkers, as the cobalt slowly poisoned the heart.
Zinc is an important trace metal and is found in comparatively high concentrations in the skin, the eyes, the liver, the pancreas and in the bone.
One of the first discoveries about the importance of zinc was the realization that deficiency leads to disease. In some parts of both Egypt and Iran there is a deficiency of zinc in the diet. In these areas there is a tendency for boys not to mature properly, and not go through puberty. This leads to people over 20 having the appearance of 10 year olds. Adding zinc to the diet of these boys brings about rapid maturation.
More relevant is the role that zinc plays in the healing of the skin. Zinc given in tablet form can help to speed up healing of various types of wounds. Also, in recent years, a disease called acrodermatitis enteropathica has been recognized. Here, the skin produces eczema like symptoms, this happens particularly in the skin of infants at the time of weaning. The condition results from poor absorption of zinc and it responds well to zinc treatment.