According to Devi Sridhar, we have our health priorities all wrong. In fact, we’ve been sold a giant myth. We are unhealthily obsessed with what we can do personally – diet, exercise and the rest – and largely ignore the most important determinant of our health. This magic bullet: government.

Public health measures like universal healthcare, drinkable water, clean air and safe roads have a much bigger impact on our chances of making it to 100 than any number of gym sessions or kale smoothies. Sridhar, a professor of global public health at the University of Edinburgh, UK, has a new book out called How Not to Die (Too Soon), which makes a robust case that public health, not just individual striving, is key to living a long and healthy life.

She spoke to New Scientist about why we swallowed the myth of purely individual health, how we can make public health more appealing and what she would do if she were in charge.

Devi Sridhar: No, no! It’s super effective if you can do it. You can make the choice to be healthy if you have resources and time and education. But I think the idea that individuals are fully responsible for their health – which is what is being projected to us – doesn’t reflect the realities of people’s lives. Where you live and the circumstances you are living in affect how long you live. That’s so easily forgotten with health issues, which are seen as your responsibility. You do need people to have agency over their lives and feel like they can make change. But actually, when we see change at a population level, where does it come from? Generally, it comes from governments.

It makes us feel empowered. People are like, “What can I do, today?” and “I can do it if I’m tough enough!” But it’s difficult to get people to think about wider structural issues and how to change them. And we aren’t exposed to that as much. We’re exposed to self-help books – the wellness literature – which are great if you have time and resources. But there’s less about the structural factors because people can’t see it as directly applicable to their lives. And there’s a lot of cynicism about politicians, thinking that they’re all the same and nothing ever changes.

I think it depends on the issue. With diet and fitness, you can take a lot of responsibility. But with things like air pollution and clean water, what can you do individually? You’re at the mercy of the place you live and your government.

Yes. It’s the marketing. We seem to think things that are marketed and sold to us in the right way are better. I think there is a real marketing problem in public health. The past years probably haven’t helped. Public health is seen as draconian and overbearing, taking away freedoms instead of giving freedoms.

It’s about how we talk about public health. Rather than saying that it’s good for the planet or it’s good for society, we could talk about it in terms of how it makes life easier and better. I think people want to know, why is it good for me? It makes me sound cynical, but that’s the world we live in.

I think part of it has to do with social media and the fact it doesn’t matter if you are accurate or not: popularity determines truth. For instance, you have Joe Rogan on his podcast talking about measles – saying that everyone had measles when he was a kid and it was all normal. It’s astonishing. He isn’t a doctor. He isn’t a public health expert. He’s just giving his opinion. But he will be more influential than any health agency. If I came out and said, “You know what the secret to longer life is? Gin and tonic!”, it would get a million clicks. I think that’s the challenge.

There’s always resistance to change. Think of the smoking ban in pubs, there was resistance. When seat belts came in, there was resistance. But generally, resistance comes in the first six months or year, then people get used to it and that becomes the norm. Norms are changeable.

Because I’m in Scotland, I have to say Dunblane. The gun legislation [put in place after a school shooting in 1996 using legal firearms] was a hard-fought battle, there was real resistance, but the pay-off is decades of no mass shootings in British schools. Many lives have been saved. And we’ve seen that template used around the world.

The places to look are what we call the better-performing countries – places like Japan, which has one of the lowest rates of chronic disease and highest rates of cancer survival. So, it’s looking at the best performers and saying, if every country looks like that, what would the numbers be able to come down to? Japan’s is remarkably low, estimated at about 10 per cent.

Our aim should be increased life expectancy for all – getting to 80, 90, possibly 100. If you can die of old age, you’re doing pretty well, right? Because it means there’s no identifiable disease or organ failure.

I think we have to see ageing as a positive force instead of a negative one. We should talk about healthy ageing, not getting to 100 for the sake of getting there, but with full mental and physical abilities, without chronic diseases like diabetes or hypertension, which are a burden on the healthcare system, and with the ability to live independently, which takes pressure off social care.

Being realistic, it’s probably a 10-to-20-year timescale. Things like reversing childhood obesity and changing city design aren’t possible overnight. But they have large pay-offs over time. One of the problems is that our current model of government is news cycle to news cycle. It isn’t even year to year. It’s headline to headline, and it’s incessant. So, there’s no bandwidth for people to think 10 years or 15 years ahead because they are caught up in it.

OK, so if you were in charge of the National Health Service (NHS) in the UK, what changes would you make? 

I’m sure they’ve thought about this, but for me, prevention. We spend far less on prevention and far more on acute care. Right now, the focus in the UK is on hospitals and ambulance wait times, and it’s only going to get worse with an ageing population. So, I think I would go straight to prevention. What are the cheap ways we can invest in prevention to detect things earlier? Pick three or four issues that are the main reasons for hospital admissions and ask, how do we address them?

For example, we know hypertension is a silent killer. Could we have a programme where people go in and get their blood pressure checked once a year? It might cost more in the first year, but five or 10 years down the line, you’re saving money. We could also take regular measurements of things like waist circumference, abdominal fat levels, sugar and cholesterol in blood, or even grip strength.

We last interviewed you during covid, when you said the pandemic was an opportunity to tackle some long-standing public health issues. Did that happen? 

No. I think, if anything, there has been a backlash against public health and a backlash against state intervention because it was so draconian, in the sense of lockdowns and wearing masks. So, I don’t think we have seized that moment. It’s quite fascinating what has emerged from the pandemic. Now there is even more emphasis on individual responsibility rather than acting collectively. 

Did we learn the lessons of the pandemic itself, and is the world better prepared for the next one? 

It depends what you look at. In public health, I’d say no, we’re going backwards. The public health infrastructure, like the testing infrastructure in the UK, has been completely dismantled. But in scientific progress, I’d say yes. We are better at designing vaccines. We have better vaccine platforms, more streamlined research. The scientific community has become faster and more adept. I’m pretty sure that if avian flu starts spreading [among humans], the UK government will have a vaccine, they’ll get it into clinics. They’ll be ready to go.

One quote near the end of your book jumped out at me: “We don’t need more research.” Really? 

Yes. We know a lot. We can probably get 90 per cent of the way there with existing knowledge about how to improve public health at a population level. Of course, there is always room for further research, but do we need another study showing that exercise reduces your risk of heart attacks? Probably not. It can almost be a distraction to say, “Let’s do more research.” Because you can just delay a decision. That was what I was trying to get at.

Globally, are we going in the right direction on public health? 

I think, in general, yes. Life is getting longer. We live better today than 100 years ago. We maybe aren’t making progress as fast as we could, and there are some places where things are being rolled back. But the larger trajectory is that we’ve made so much progress. 

What do you hope people will take away from the book? 

That politicians can make a difference. Think of the NHS. There was a deliberate decision made to create it. It didn’t just randomly happen. I’m trying to show that, in the world we live in, everything we have is a set of policy choices that were made before, sometimes decades ago, that we’re benefiting from today. What we do today, we may not see improvements from, but future generations will. What I’ve tried to do is give a bit of hope.