Free radicals theory questioned, as is cause of cancer and arthritis

Main Category: Cancer / Oncology
Article Date: 26 Feb 2004 - 0:00 PST


It is widely believed that free radicals, produced when our bodies fight infection, inflict damage on our tissues.

There is a wide range of drugs designed to mop up these excessive amounts of free radicals. The reason they are given is to prevent damage and disease.

This theory is now being questioned by researchers at University College London (UK). They think the theory could be wrong. They say their findings could change the way free radicals are treated.

Standard theory believes that the molecules (free radicals) cause so much tissue damage that they are major contributory factors in many diseases such as cancer, arthritis and heart disease.

The drugs that mop up these free radicals are called antioxidants. For the last 30 years the pharmaceutical industry has developed antioxidants that stop the production of free radicals and/or mop them up so that they do not damage tissue.

Some vitamins attack free radicals - mainly vitamins E and C.

The research team at University College London (UCL) say that their research shows that the evidence on which this theory was first based is wrong.

Dr Tony Sega, one of the researchers,l said: 'White blood cells produce oxygen free radicals, and the process by which they do so is essential for the efficient killing of microbes. However, people in whom this process is defective are prone to severe, chronic and often fatal infections. This fact has led to the presumption that the oxygen free radicals themselves are highly toxic, and that if they can kill organisms as tough as bacteria and fungi they can also damage human tissues. However, our work shows that the basic theory underlying the toxicity of oxygen radicals is flawed.'

The team found that it was not free radicals that make white blood cells so destructive. It was enzymes which digest foreign invaders.

The flow of potassium within the cell triggers the production of these enzymes.

They found that when they blocked this flow, the cells could not kill off foreign invaders any more. They used a chemical developed from scorpion venom to block this flow.

This shows, they say, that free radicals are not the toxic particles we all had assumed.

The team said that we (the pharmaceutical industry) have spent billions on a red herring.

Dr. Sega said 'Many patients might be using expensive antioxidant drugs based upon completely invalid theories as to their therapeutic potential. All the theories relating to their causation of disease by oxygen free radicals, and the therapeutic value of antioxidants must, at the very least, be re-evaluated.'

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