From Ergo Log
People who do intensive training are protected against toxic metals that accumulate in our bodies as a result of environmental pollution. Researchers at the University of Extremadura in Spain discovered that athletes eliminate many of the toxic metals in the urine.
We are continuously exposed to minute quantities of toxic metals like lead and cadmium and absorb microscopic quantities through our food and the air we breathe. This is the price we pay for living in an industrial society. The toxicity of the metals depends on the degree of exposure and also the power of the body to detoxify. The Spanish were interested to know more about the latter factor.
The Spanish researchers wanted to know whether athletes eliminate toxic metals more easily than people with a sedentary lifestyle. Athletes eliminate all sorts of useful minerals like sodium, potassium and even magnesium and calcium through their sweat and urine, so maybe there are also ways in which athletes' bodies also eliminate toxic industrial metals. The researchers therefore studied 21 runners – middle distance runners – and measured how many toxic metals they eliminated in their urine.
The researchers started by looking at tungsten or wolfram [W], an element found in the filament in electric light bulbs and in the ball of ballpoint pens. Tungsten is not very toxic.
Cadmium [Cd] is a metal released during zinc mining. It's found in paint and batteries, but since it was discovered to be toxic its use has been restricted by legislation. High doses of cadmium are carcinogenic, and low doses can cause osteoporosis and kidney failure.
Tellurium [Te] is found in electronic components. It suppresses selenium in the body and thus deactivates protective seleno-enzymes. As a result tellurium increases oxidative stress.
Beryllium [Be] is found in some car parts and electronic equipment. It is capable of causing lung damage.
And finally lead [Pb] is found in cheap petrol, paint and batteries. It's the cause of a whole list of toxic effects. Lead is capable of causing damage to the heart and blood vessels, the kidneys, genitals and immune system. Damage to the brain can also lead to early onset dementia.
The researchers compared the concentration of these five metals in the urine of the runners with that of a control group of inactive subjects. The people in the control group were selected on the basis of weight, sex and diet, so that they resembled the athletes in the experimental group as far as possible.
"Our study was limited to a relatively small number of cases, and additional studies with blood and sweat samples are needed to confirm the beneficial role of physical activity in increasing toxic elements excretion", the Spanish researchers admit. Nevertheless, they regard the results as encouraging. "Our results suggest that physical activity could provide a positive protective effect against diseases related to the action of toxic metals, especially for individuals in large cities who are more exposed to pollution."
Eur J Appl Physiol. 2011 Dec 17. [Epub ahead of print].