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Hello and welcome to More or Less on the BBC World Service. I'm Tim Harford.

You may remember this story from December, which made headlines around the world.

An apple a day keeps thousands of deaths at bay.

Why an apple a day could be as good as a statin for over 50s?

The source of the headlines was a study that featured in the British Medical Journal or BMJ.

But contrary to what you might think, this wasn't an exhaustive clinical trial of munching on apples.

Instead, a group of researchers at the University of Oxford in the UK used mathematical models,

based on earlier research about the health benefits of fruit and veg,

to test the old proverb and apple a day keeps the doctor away.

They essentially did two thought experiments.

First, they thought to themselves, currently there are five million people considered at risk of heart disease,

who are already prescribed statins by the UK's National Health Service.

So what would happen if we prescribed statins to everyone in the UK population over 50?

And how many lives might be saved each year by preventing heart disease if we did that?

And then the second thought experiment, why not go one step further

and see if we could work out how many lives could be saved each year from heart attacks and strokes

if everyone in the population over 50 had an apple?

Low and behold, the researchers found that eating an extra apple a day would indeed save 8,500 lives,

almost as many as offering statins to all over 50 year olds.

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