UCL News


UCL study questions basis for treatment of diseases including cancer and arthritis

26 February 2004

One of the methods for treating diseases that include cancer, arthritis and radiation sickness is challenged by new research by a team of scientists at University College London (UCL).

The current orthodoxy on the role played by oxygen free radicals in the development of a number of diseases is called into question by the UCL team in a paper to be published in the 26th February edition of Nature, in research that may hold profound implications for the standard approach of the medical profession and pharmaceutical industry in treating these conditions.

It is currently held that oxygen free radicals, atoms or groups of atoms produced by white blood cells, are responsible, if produced in excess, for the production of conditions such as arthritis, arteriosclerosis and many others, including cancer. That is why, since the 1970s, medical practice and the pharmaceutical industry have sought to develop drugs to stop the production of free radicals and mop them up with antioxidants (substances capable of preventing the oxidation of organic molecules) as part of the process of treating such diseases.

Following extensive study, the paper categorically discounts the primary evidence upon which this theory is based, and suggests that instead we need to look at other potential treatments, and that specifically treatments should move towards the regulation of enzymes released from neutrophil leukocytes, the most numerous of the white blood cells.

"White blood cells produce oxygen free radicals, and the process by which they do so is essential for the efficient killing of microbes," says Professor Tony Segal of the Centre for Molecular Medicine within UCL's Department of Medicine, one of the authors of the research.

"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. Free radicals are believed to be promoted by many agents, including smoking and atmospheric pollutants and smoking, and have been implicated in the production of conditions that include cancer, arthritis, arteritis many other conditions caused by an initial inflammation in which these neutrophil leukocytes accumulate.

"However, our work shows that the basic theory underlying the toxicity of oxygen radicals is flawed. Tens, if not hundreds, of millions of pounds have been misspent by the pharmaceutical industry in chasing the red herring of the involvement of oxygen free radicals in the causation of many diseases . 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."

Notes for Editors

1. The large-conductance Ca²+ -activated K+ channel is essential for innate immunity," is published in the 26th February edition of Nature.

2. Requests for interviews and further information should be made to Dominique Fourniol, on +44 (0)207679 9728.