Hope in a humble worm (Article by Chang Ai-Lien) (Note: On Ageing Matters)

Hope in a humble worm (Article by Chang Ai-Lien) (Note: On Ageing Matters)

Saturday Special Report
The Straits Times

Apr 16, 2011

Hope in a humble worm

Simple organism studied in bid to find way to extend human lifespan
By Chang Ai-Lien, Senior Correspondent

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PROFESSOR Barry Halliwell hopes to unearth some of the secrets of ageing from a humble worm.

The internationally acclaimed biochemist has discovered compounds that extend the lifespan of C-elegans - a widely used research organism - as well as free radicals which can halve its life. Although it is early days yet, the hope is that once more is known about how such chemicals work, they can eventually be used to extend human life.

Prof Halliwell, who is deputy president in charge of research and technology at the National University of Singapore, is well known for his seminal work on the role of free radicals and antioxidants, and is one of the world's most highly cited researchers in biology and biochemistry. Some researchers believe antioxidants may protect cells from free radicals, by-products produced when the body processes oxygen and which damage cells and increase the risk of diseases such as cancer.

Explaining the ageing process, Prof Halliwell said: 'If everything in a person's body declined at the same rate he'd probably live to the age of 120.

'But that doesn't usually happen because one organ will fail first, plus disease becomes more common with age, and people also heal more slowly.'

Ageing is affected by a person's genes and lifestyle, he added, but there is also a random element which is unknown.

Enter C-elegans. The 1mm roundworm is popular with scientists for a number of reasons. It is transparent - so changes in organs and cells can be easily studied; it does not live long - 22 days on average; its complete cell structure, development and genetics are well studied; and it has enzymes and genes also present in people.

In his laboratory, the worms used for such research are genetically identical clones, and they have exactly the same environment. Yet some live just 10 days, and others to the ripe old age of 34 days.

'Despite the identical conditions, some worms remain extremely active while others move less and less, just like how some old people are vigorous but others become moribund,' Prof Halliwell said.

So he is trying to tease out these differences, in addition to examining compounds such as antioxidants and looking at how they affect lifespans.

Testing many plant-based compounds, his team has identified two secret ingredients which increase the worm's lifespan to 40 days.

They are now fine-tuning the optimal dose and studying how they work.

On the flip side, free radicals have been found to dramatically shorten the worm's life, to about 10 days. But the process is more complicated than it seems, said senior research fellow Jan Gruber.

Knocking out genes that create antioxidants has not had the expected effect of shortening lifespans, he said, as systems are complex and compensate for the loss.

Also, free radicals are not just toxic chemicals. They are believed to play a role in energy regulation.

'What we're trying to do is to make sense of these single mechanisms in a holistic manner,' he said.

Years of work remain. So far, high doses of antioxidants have not been proven to be useful in preventing disease in people, as a range of them is needed.

Prof Halliwell said: 'At the moment, all that we can conclusively say is that the populations of advanced countries would benefit from eating less fat and more fresh fruit and vegetables and perhaps taking multivitamin or mineral supplements.

'Even Hippocrates, who knew nothing about antioxidants, came to the same conclusion about diet using simple clinical observations and relying on his own common sense.'