How to reverse ageing

Ageing of the human body is fundamentally the same as the ageing of an engine.

Although the processes that drive ageing are subtler than those that drive engine breakdown, the analogy holds: it’s all about damage to functional units acquired during the normal operation of the machine. And I do mean machine—our bodies are full of machines. All of our abilities are built, maintained, and carried out by microscopic devices that support our health and survival because their specific structural features allow them to carry out tasks necessary for the tissue in which they are localised.

From individual enzymes and signaling molecules, to filters, pumps, and membranes inside and outside cells, all the way up to organs like the liver or brain, these and other machines are the basis of the complex dance of physical and chemical processes that make a body a living system rather than a random agglomeration of nitrogen, carbon, hydrogen, and oxygen.

So just like any other machine, the continuous operation of the machinery of life generates damage, and leads to the production of harmful waste products that impair the functioning of other machinery, just like engine soot from incomplete fuel combustion builds up in lubricating oil and wears the engine down. As the cellular and molecular functional units of a tissue are damaged, the tissue loses its ability to carry out its normal biological function, and the tissue or organ becomes dysfunctional. Put another way, heart failure and engine failure, strokes and blown gaskets, loss of engine performance and loss of mental performance are each examples of what happens when the damage load exceeds the machine’s built-in tolerance.

Such losses of functional units and accumulations of damaged biomolecules also drive a wide range of phenomena that we don’t usually label “diseases,” but that nonetheless contribute to the frailty, illness, loss of quality of life, and malaise that plague elderly people. These include the impairment of the immune system with age; the loss of muscle mass and strength; declining lung capacity; the rise of inflammation and oxidative stress in the body; and the early phases of specific diseases of ageing, in which function is compromised but to a degree that does not meet the usual threshold at which a particular disease is customarily diagnosed.

So the question is: what do we do about it? This table contains some ideas:



By the 1990s, scientists who study ageing knew a lot about what types of damage contributed to the ill-health of old age (left column in the table). In 2000, colleagues and I proposed a panel of biotechnologies that either already existed in principle, or that were foreseeable at the time from existing scientific developments, that could together realise the strategies I outline in the table. Biomedical strategies existed, we could see, whereby the various different kind of damage that accumulate in the ageing body and progressively impair its function could be removed, repaired, replaced, or rendered harmless to us (right column in the table). Once all that damage was removed, we could be confident that diseases driven by that damage would be averted, for the same reasons that removal and replacement of worn-out parts in our cars prevents failing brakes and engine failure.

SENS Research Foundation is researching in all the areas mentioned in the table. Because each form of aging damage degrades the healthy function of a specific tissue in a characteristic way, we will only realize the full potential of this approach when a full, comprehensive panel of them can be tested at once, in the same living thing—and then rolled out for humans.

As we are able to apply rejuvenation therapies to more and more kinds of damage in more and more tissues, our bodies will increasingly perfectly resemble our youthful, robust selves. And because these therapies restore old tissues to youthful integrity rather than trying to manage the risk factors that contribute to its progressive loss, we can keep repeating rejuvenation treatments as often as we require, each time effecting a restoration of tissue integrity and function—and thus of youthful health.

 

Aubrey de Grey will be speaking about his research on aging at HowTheLightGetsIn, the world’s largest festival for philosophy and music, at the end of this month. The festival is running from 21^st May to 31^st May in association with Prospect.