John Murphy (Reid, Australian Labor Party) Share this | Link to this | Hansard source

Among the more depressing forecasts for the near-term future is the possibility that health services will be overwhelmed by an ever-increasing number of sick and elderly people, while younger taxpayers will be burdened by a ballooning health budget. So far, such visions of gloom have failed to materialise as advances in health sciences have to some extent reduced the demand for expensive medical interventions. Yet figures show that it presently costs about four times as much to treat, in a given year, a 65-year-old for health care than it does to treat a 40-year-old. Obviously what is urgently needed is some effective means of reducing the cost of medical treatment for the elderly while reducing suffering of both older people and their families. Fortunately, recent discoveries by scientists have made such a prospect less a dream and more a reality, and we are—as a result of recent advances in the understanding of the biology of ageing as well as the discovery of new drugs that retard the ageing process—for the first time about to be able both to retard the decline in health and to extend the maximum lifespan of normal individuals.

In 1964, Canadian researchers, as part of an expedition to Easter Island, known by its inhabitants as Rapa Nui, collected soil samples that were later found to contain a bacterium that produced a metabolite known as rapamycin which has since been found both to increase the lifespan of mice and to improve the health of elderly mice. Of course, there have been many claims of the discovery of such substances in the past. Yet for the first time a drug has been identified that has been conclusively shown to extend the maximum lifespan of mice by some 12 per cent at the same time as it extends average survival by a third of old mice presumed to be too damaged by ageing to enjoy any benefit of the drug. For a human, such an effect means that an eighty-year-old person may have 10 healthy years added to their lifespan.

Some may say that, since mice are not human, such findings may not be relevant to human health. Yet, in medical research, mice are considered model organisms and are widely used to study human genes in human diseases. In responding to concerns about the relevance of medical investigations on mice, the European Commission held a workshop in London in 2010 entitled 'Are Mice Relevant Models for Human Disease?' The workshop found that, since mice are mammals, the mouse genome is very similar to the human genome and that the availability of a unique battery of sophisticated molecular and genetic tools, together with the animal's small size, makes research on mice a cost-efficient model for providing functional information on human genes in health and disease. This means that findings in mice are directly relevant to human health studies.

Scientists have long studied the biological processes involved in ageing and, in the 1990s, discovered that a central component of a cell's energy metabolism is a protein complex called TOR—an acronym for 'target of rapamycin'—which is a mechanism that supervises many growth related activities. TOR is a nutrient sensor that prompts cells to divide when food is abundant. Conversely, when food is scarce, the activity of TOR declines and cells are prompted to break down defective cellular components and use the by-products either for energy or for building new cellular components.

That a nutritionally-adequate, near-starvation diet can extend the healthy lifespan of individuals has been understood for more than 50 years. However, few people are willing to continue with a diet of what has been described as being 'of anorexic severity' despite the well attested benefits of such a regime. It now appears that drugs similar to rapamycin may be able to confer the benefits of a calorie restricted diet by reducing the activity of TOR, with the effect that ageing slows and tissues stay healthy longer. Studies show that the inhibition of TOR not only mimics the effects of calorie restriction but also seems to enhance the effects of so-called genome genes, which have been shown to significantly extend the lifespan of the other organisms.

Discoveries by scientists have raised the possibility that human ageing may be retarded by drugs and that major age related disorders, including cancer, Alzheimer's, Parkinson's disease, heart disease, muscle degeneration, type 2 diabetes, osteoporosis and macular degeneration may be avoided by many people, which would be a huge benefit to all arising directly from basic research. (Time expired)