Researchers have been studying for decades how ageing can be delayed. One of the most striking findings comes from experiments with mice that were given a mutation causing the growth hormone not to function properly. These mice lived up to 70 per cent longer than normal mice. The growth hormone plays an important role in growth and metabolism, but it also influences the ageing process.
In humans, there is a condition similar to this mutation, called Laron syndrome. People with this syndrome produce less or no response to growth hormone. Although they sometimes have fewer age-related diseases, they do not live significantly longer than average. This makes it difficult to translate the results in mice directly to humans.
New research shows that interrupting the function of growth hormone in middle-aged mice still has an effect on ageing, but this effect is much smaller than when this adjustment is made from a young age. It extends lifespan by less than 10 percent, mainly in male mice, whilst having less of an effect in female mice.
Science shows that interventions that slow down ageing generally work more strongly in short-lived species than in long-lived animals such as humans. Therefore, it is uncertain whether therapies targeting the growth hormone system can make a significant contribution to healthy ageing in humans.
This discovery highlights the importance of research into ageing processes, but also demonstrates that not every intervention in animals is easily translatable to humans when it comes to healthy ageing.
Source: Reason
