A radical is a group of atoms which can combine in the same way as single atoms to make a molecule. Free means uncombined. A free radical is a state in which a radical can exist before it combines – an incomplete molecule containing oxygen which has an uneven electrical charge. High energy oxygen atoms are known to form atheroma.
As well as being substances that take part in a process of metabolism, free radicals can be found in industrial fumes and cigarette smoke. They are oxidants and have an anti-bacterial effect. But their activity is not confined to bacteria alone. When produced in large amounts as in inflammation and infection, they may have a damaging effect upon the lining of blood vessels and other tissues. An excess is produced in ischaemic heart disease. They have been shown to be involved in jet lag, Alzheimer’s disease, rheumatoid arthritis, thrombosis, heart failure, cancer, irradiation sickness and a weak immune system. Damaging to the DNA, they are probably the greatest single cause of ill health. They hasten the ageing process. Vitamins A, C, E, being antioxidants and the mineral Selenium stimulate certain enzyme systems to limit damage done by these destructive elements.
Losing weight is believed to generate free radicals – a metabolic side-effect of dieting. See: ANTIOXIDANTS.