How we age

The journal Nature Genetics reports scientists have identified a gene sequence that suggests some people are genetically programmed to age at a faster rate than the rest of us. It’s the first time a link’s been found between DNA and human lifespan and it raises the hope of drugs that could prevent the biological deterioration behind age-related conditions such as heart disease and cancer.

The promise and fascination of this area of research was highlighted by last year’s Nobel Prize for Medicine, awarded to three US-based scientists who identified both how our chromosomes are protected by telomeres and the enzyme that makes them.

The telomeres are end sections of chromosomes which act like the plastic tips of shoelaces and stop them from fraying. The problem is they shorten each time they replicate and eventually are so short that replication becomes impossible and the cell dies forever.

The latest study has observed that a variant of the gene determines not only how long the telomeres are when someone is born but also how quickly they shorten. Professor Nilesh Samani of the University of Leicester, one of the study leaders, found a common sequence of DNA in 45% of the 3,000-strong trial group was strongly linked to a person’s biological age. The majority of the population don’t carry copies of the variant and don’t appear to age as fast.

Professor Samani said: "It is the first step to understanding why people age. Once we have a full understanding we should be able to manipulate it in a manner to influence how someone ages."

All of which suggests that in the longer term it may be possible to extend the life spans of those who carry the gene variant.

In the meantime, those of us who test positive as young adults can expect a prescription for cholesterol-lowering drugs - and the familiar encouragements to exercise, eat healthily and avoid smoking.