A cardiologist’s plea: If not for your planet, do it for your health

Dr Leslie Cho, professor of medicine and section head of preventive cardiology and rehabilitation at world leading academic medical centre, Cleveland Clinic, discusses with Race to Zero editor Charlotte Owen-Burge the growing impacts of climate change on our cardiovascular health. By Charlotte Owen-Burge | May 19, 2021

Charlotte Owen-Burge: Dr Cho, could you tell me about the impact that climate change is having on our cardiovascular health and the range of conditions affected?

Dr Leslie Cho: The really unfortunate thing about climate change and extreme heat is that this is something that can be prevented. However, we’re seeing a rise in cardiovascular mortality as well as heart attacks and strokes. We’re also already witnessing an increase in things like diabetes and high blood pressure. [Climate change] is having, what we call, a cardiometabolic effect.

People with high blood pressure, the elderly, the diabetic, are all affected by extreme heat. And there’s very good, growing, evidence to suggest that extreme heat increases your chances of blood clots and so you’re more likely to have a heart attack. It causes an increase in inflammation which we know leads to plaque rupture which is how heart attacks and strokes can occur.

Of course, extreme heat can also lead to other things like wildfires which then creates air pollution which can cause heart attacks and strokes. But it also has this very insidious effect of increasing things like high blood pressure and diabetes. And there’s very good data to show that even moderately high temperatures over a period of a few days can lead to a 1-3% increase in heart attacks, which is astounding.

Air pollution is also having a direct impact on children – from childhood asthma to respiratory diseases. It can also lead to arrythmias, clotting disorders and an increased risk of getting diabetes and high blood pressure.

Air pollution can increase the risk heart attacks and strokes. Credit: Marcus Kauffman

A report from the Lancet found that between 2000 and 2018, heat-related mortality in people over-65 had increased by 53%. Given that the world has already experienced a 1°C increase since pre industrial times, what do you believe will happen to our cardiovascular health as temperatures continue to rise further?

We don’t have to imagine it. We’ve all experienced what it’s like for a healthcare system to be overwhelmed. And when you have an increase of temperature leading to increased cardiovascular mortality – heart related death – and of course heart attacks and strokes, coupled with an ageing population, your health system is going to be inundated.

We’ve lived through it this year and last year. And it has a global impact. But, forget healthcare. Let’s say you are young and you don’t care; you think you’re immune (although young people are much more in tune with climate change than the middle aged and the elderly, I think). But even if you say, “I’m healthy and that doesn’t affect me”, the global impact of this on our livelihoods, our lifestyles, is tremendous.

There’s a wonderful poet in the US who is also an agriculturalist and activist, his name is Wendell Berry and he has a very wise saying: “The Earth is what we all have in common”. It’s 100% true. In 2020 we learned what it means to be intimately connected to one another; that there is nowhere you can go and no amount of wealth can make you safe from pandemics.

And as the effects of climate change worsen, and as our temperature rises, zoonotic diseases will only continue to increase. And so, it’s really important for all of us to take it seriously. I’m a cardiologist, a heart doctor, and for me, cardiovascular disease prevention has been a calling and I often think about that: how do I reduce the risk of heart attacks for my patients. We can talk about the importance of eating healthily, which is very important and intimately linked to climate change, and getting exercise which is so important too. But you can’t talk about prevention without talking about climate change these days because they are so intimately linked.

35% of carbon emissions come from the food we eat.

What should people be doing in their everyday lives to ensure they’re protecting their health from the growing impacts of climate change?

There are some astounding statistics out there. About 35% of greenhouse gas emissions come from the food we eat. Not just food waste, not just transportation, but the food we eat. And the amount of animal products we’re eating, especially beef and dairy, is having a dramatic impact.

But the really great thing, or the important thing, is that eating less meat makes you live longer and it reduces your chance of having a heart attack or getting cancer. So, if we can do something good for our health, and it’s also good for the planet, what a winning combination!

So, let’s say you’re totally selfish and you don’t care about the planet. Ok fine! Do you care about yourself? Do you care about your health? What about your chances of living a long life, with less dementia, less cancer, with less chance of a heart attack? If you care about that then, great, then we can make an impact.

What kind of transportation we’re using is also super important. The great thing is, if you bike or walk to work – if you’re so lucky to be able to do that – it not only makes you live longer because you’re exercising, but it’s also good for the planet.

I think those things are really important. Sometimes we think: “I want the government to do it. I want the policies to change”. But individuals make up that policy. Individuals make up a country. It’s really important that we do everything we can to get to net zero emissions. Not just for our children but for ourselves.

Can you paint a picture of a net zero world in terms of our health?

I want all of us to be hopeful because how can we live if we all live in doom and gloom? But there is really good evidence to say that if we get to net zero we can prevent excess mortality.

Often, we might think on a personal level: “what does zero carbon emissions really mean?” Well, what if that means less heart attacks, less strokes, the chance to live longer?

There’s no doubt in my mind that all of us know, and all of us have felt, what it’s like during a pandemic and if we had that in 2020, imagine what 2040 will be like when we have an increase in temperature and when our healthcare is inundated with cardiovascular events.

And we can do something to stop it today. I really believe people everywhere are good fundamentally and I think society has to make that choice but society starts with individuals.

We’re all responsible for our own health and I think that if nothing appeals to you – if climate change doesn’t appeal to you –  just for your own selfish benefit, for your health’s sake: eat less meat, exercise more and reduce your exposure to air pollution. Just these things alone should galvanize society and the public into adopting things that will help tackle climate change.

Who is most at risk from the effects of climate change?

The elderly and children. Th elderly because they have more health related problems as they get older and people, for instance, who are diabetic are hypertensive. And children, because they’re going to be living longer with exposure to an unhealthy climate.

But it’s also going to create incredible disparities between rich and poor countries and even within a rich country, the haves and the have nots. We’ve seen what disparities in healthcare have done because of COVID19 in countries like the US, where you have an incredible income disparity, but climate change is just going to make it worse. Because who’s most vulnerable from environmental exposure? People who are poor. And that goes from a micro level, within countries, but it also goes from rich countries to poor countries: it’s going to have a devasting effect not just individually but also as a society and globally and I think we should have a moment of pause about that.

I think it’s important for everyone to remember that we don’t live in isolation in 2021: we live intimately connected to one another. There is nothing that’s happening around the world that’s not going to come and affect you.

This interview took place on May 17 2021. It has been edited and condensed for clarity.

Find out more about the Race to Zero and the Race to Resilience.

Dr Cho featured in the fourth episode of the Royal Society of Medicine’s Health emergency of climate change series. Upcoming events include:

The unborn child and children’s health – Episode 6
Tuesday May 25 2021, 6:00pm to 7:00pm BST
Free, CPD accredited
Register today ➤ 

Mental health in a planetary crisis – Episode 7
Tuesday June 8 2021, 6:00pm to 7:00pm BST
Free, CPD accredited
Register today ➤ 





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