 For almost 200 years now, human lifespans been increasing at an astonishing six hours a day in most developed countries. And so we're seeing some remarkable lifespans. And I think this is something to be celebrated as a crowning achievement of civilization. But it is coming with the downside because healthy years are not keeping up with the overall increase. So there's a growing period of disability and illness at the end of life. So by the age of 80, most Europeans have at least eight different medical conditions. So we tend to take the ills of old age for granted as somehow natural. But should we? Why aren't we up in arms about aging? If young people lost their teeth and went deaf, got cancer, dementia, couldn't work or even enjoy themselves, we'd be up in arms. So why are we accepting that deal for old people? What if getting old didn't mean getting ill? So aging isn't inevitable. There are a lot of creatures out in the natural world who don't age at all. Things don't get worse for them as they go through their lives. And people who die at very old ages in the 90s or over 100 often have very little wrong with them at the end of their life. They're relatively healthy. So it's possible to stay healthy as you get older. And really quite simple interventions just putting an animal on a diet can produce a remarkably broad spectrum protection against cardiovascular disease, cancer, brain atrophy. And the animals are stronger and more active at the end of their lives. So a simple intervention can protect against multiple different age related conditions. We don't know whether dietary restriction would work in people because there's never been a successful clinical trial. And people find it incredibly difficult to adhere with a dietary restriction regime. So the kind of research that I do is actually using animals to try to understand how dietary restriction works so that we can potentially target it with drugs in humans. And the animals that we use to do this are much shorter lived than recess monkeys, much more practical. So yeast, worms, fruit flies and mice. And what this cast of characters has told us is both how aging works and how interventions like dietary restriction can ameliorate its effects. So what dietary restriction does is to go for the basic mechanisms of aging, the deterioration in the genetic materials, in cells, in tissues and in the ways that they communicate with each other. So it orders the expression of genes that are involved in the aging process and hence protects against it. And of course genes are remarkably similar in animals and humans. We can often take an animal gene or a human one even, put it into a different laboratory animal and it works just fine in its new environment. And genetic studies of aging human populations have shown that people who live to great ages often have specific variants in the genes that have turned out to be important in animals. And that means we can target them with drugs like rapamycin, which is a licensed drug. It can increase lifespan in mice if you feed it to them. And it also boosts up the rather poor immune response of elderly people to vaccination against flu. So the thought here is perhaps instead of waiting for these age-related conditions to crop up in the first place and then treat them individually and as they arise. Perhaps we could use drugs to protect people against groups of age-related diseases simultaneously. There are going to be some challenges in doing that, particularly if we're talking about developing new drugs. So we'd need very safe drugs, potentially administered almost population-wide over a long period, very expensive clinical trials for the pharmaceutical industry. But happily it's turning out that many already licensed drugs that are used to treat age-related diseases can have this kind of protective effect. And the principle of very widespread use of safe drugs to prevent diseases that haven't yet happened is very well established for cardiovascular disease. So there's been a massive decrease in cardiovascular disease as a result of the use of statins to deal with blood lipids and blood pressure lowering. Now, ageing is quite a complicated process. There are a number of different things that go wrong in parallel and interact with each other. So we'd probably be talking about a cocktail of preventative drugs in a single pill. It would be a poly pill rather than a single drug if it was going to be fully effective. And obviously this is something that communities are going to have to discuss. There are social implications. We would have to be talking about very safe drugs, but we're living much longer than in our evolutionary past. And our bodies simply are not engineered to last this long. They really do need help to stay healthy in this new period of long lives. Thank you.