Ageing is a natural process whereby the molecules, cells and tissues in a body accumulate damage, leading to loss of function and increased risk of death. Ageing occurs at many levels of organization, including modifications and damage to macromolecules, changes in gene expression, alterations in cellular biochemistry and the metabolome, damage to tissues and the systemic environment, and alterations to the behaviour of the whole system. In developed countries today, ageing is the major risk factor for predominant killer diseases such as cancer, and neurodegenerative and cardiovascular disorders. By understanding the mechanisms of ageing it should be possible to help relieve this disease burden, and to work towards developing interventions to prevent the complications of ageing and ageing-related disease.
Given the importance of ageing in disease processes, understanding its mechanisms might provide the opportunity to identify interventions — genetic and environmental — that can improve health and prevent or delay ageing-related diseases1,2. Animal models, such as nematode worms, fruit flies and mice, are often used in laboratory research because many biochemical pathways are conserved across the evolutionary tree3,4. Ageing research has accelerated in recent years: perhaps the most exciting discovery has been that certain single-gene mutations can extend the healthy lifespan of laboratory animals. Outside of the laboratory, research has also benefitted from comparative work on the rate of ageing in different organisms and from population-based genetic- association studies. Experimental work in humans has looked, for instance, at the effects of diet and exercise5. Clinical work on ageing in itself is less common, largely owing to practical considerations of the time involved.
>> If I’d known I was gonna live this long, I’d have taken better care of myself.
One of the main messages coming out of this work is that ageing is the primary risk factor for diseases later in life6-10. Interventions that protect against the effects of the ageing process and extend lifespan in laboratory model organisms also delay or reduce the impact of diverse, ageing-related disability. This implies that it might be possible to develop a broad-spectrum, preventative medicine for the diseases of ageing, in sharp contrast with current medical practice, which tackles each disease separately.