The Vitamin with a Hidden Healing Touch
Byline: ANN KENT
WHICH vitamin can iron out wrinkles, prevent blindness in children, stop viruses in their tracks and repair damaged lung tissue?
It is a nutrient which once excited great interest, but has since been overshadowed by the Big Three - vitamins C, E and beta-carotene.
However, scientists now believe that vitamin A, also known as retinol, is about to have its day.
In the U.S. retinol is being studied as a possible treatment for macular degeneration (the blindness associated with ageing), for cancer, and as an immune system booster.
It is also being tested on pregnant women with Aids and as a way of reducing deaths in childbirth in the Third World.
In the UK, few people lack vitamin A in their diets. However, derivatives of retinol have been used for years to treat acne, psoriasis, wrinkles and (more recently) leukaemia.
However, the drawback of taking large amounts of vitamin A that it can have toxic effects on well-fed people. (See box top right). The situation is very different in the Third World, where millions of children are at risk of blindness caused by retinol deficiency.
For nearly 30 years, the eyesight children has been saved by high-dose supplements. Then, in the Eighties, aid workers noticed that children who received vitamin A for their eyes, were much less likely to die of two big viral killers: measles and diarrhoeal illness.
Somehow the vitamin was limiting the effects of potentially fatal infections. But before researchers had the chance to explore this suggestion, another discovery was made.
Scientists at Georgetown University School of Medicine, in Washington DC, gave retinoic acid, a powerful derivative of vitamin A, to rats with a lung condition similar to emphysema.
EMPHYSEMA is an incurable disease, usually caused by smoking, and is implicated in 30,000 deaths a year in the UK.
It occurs when the tiny air sacs through which oxygen is absorbed break down. The rats which were treated with retinoic acid grew new air sacs to replace the damaged ones.
When the results were published, the chief researcher Dr Gloria De Carlo Massaro was deluged with phone calls from desperate emphysema sufferers. She had to tell them that retinoic acid,
which is also used to treat leukaemia and lymphatic cancer, is not the same as vitamin A.
And no, they could not achieve the same effects with handfuls of vitamin A pills because the vitamin is dangerous in high doses.
What worked in rats might not work in humans, she added. 'We don't know how the retinoic acid repaired the damaged rat lungs.
We're trying to work out if it acts on the genes which control cell growth.
'We are cautiously optimistic that we may be moving towards a treatment for emphysema, but it is likely to be several years away.' Unknown to Dr Massaro, researchers in Sao Paulo, Brazil, had started to test the effects of vitamin A on middle-aged male smokers with lung disease.
Blood tests showed that the men with moderate to severe disease had lower levels of vitamin A than the non smokers and men with milder symptoms. They then gave 1,000 microgram vitamin A supplements to a group of six men with lung disease for 30 days and compared their progress with six similar men who were given a placebo (dummy pills). …