Red meat death risk?

Summary

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Podcast Summary: "Red Meat Death Risk?"

More or Less – BBC Radio 4
Host: Tim Harford
Date: March 16, 2012

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Episode Overview

This episode of More or Less dives into two primary topics:

1. The statistical realities behind headlines claiming red meat increases the risk of death, based on new Harvard Medical School research.
2. An investigation into the world's largest employers and setting the record straight on common misstatements.

Throughout, Tim Harford and guest expert Professor David Spiegelhalter (University of Cambridge) break down how to interpret risk statistics in the news, debunk myths, and clarify the meaning behind big, headline-grabbing numbers.

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Main Topic 1: Does Red Meat Really Increase Your Risk of Death?

The Headlines and the Study (00:01)

• Tim Harford introduces alarming news headlines such as “Red Meat Death Study” and “A hot dog a day raises risk of dying,” sparked by Harvard Medical School research on over 120,000 people over 20 years.
• The study reported a 13% increased risk of death for each extra portion of unprocessed red meat consumed.

Clarifying the Statistics (01:54)

• David Spiegelhalter’s translation:

  "If there were two men, say, aged 40, and they were really the same ... but the only difference is that one ate an extra portion of meat every day ... the one who likes the meat has a 13% extra risk of dying each year."
  (01:54, David Spiegelhalter)

What Does a 13% Increased Risk Mean? (02:23-02:49)

• Tim Harford challenges the raw interpretation of a 13% increase in “risk of death,” asking:

  "Does this mean it's actually 113%?"

• Spiegelhalter explains that despite headlines, this translates in practice to eating red meat daily corresponds (on average) to living one year less between ages 40 and 80.

  "The person who eats more meat is expected to live one year less than the person who doesn't eat so much meat."
  (02:49, David Spiegelhalter) "The 40 year old who does eat the meat, you'd expect, on average, him to live to 79. And the person who doesn't eat so much meat, you expect him to live till 80."
  (02:49, David Spiegelhalter)

Breaking it Down: Daily Life Impact (03:19)

• Spiegelhalter puts it in everyday terms:

  "That one year off our life between age 40 and 80, that's equivalent to losing half an hour a day ... [from] eating his burger ... equivalent ... to smoking two cigarettes, for example, is about half an hour of your life, or being ... 5 kg overweight."
  (03:19, David Spiegelhalter)

Processed Meats and Statistical Causality (03:47 - 04:36)

• Harford notes health risk figures are even higher for processed meats like bacon.
• BUT: Correlation does not imply causation – while a strong correlation exists, it’s not proven that red meat directly causes cancer or heart disease:

  "We can't say there's cause and effect here ... All that can be said is that there appears to be a strong correlation ..."
  (03:47, Tim Harford)

• Researchers controlled for many factors (alcohol, calories, activity, family history), but there could still be unknown variables.

When Should We Trust These Findings? (05:11)

• Spiegelhalter advises considering the consistency of repeated findings:

  "I think you need to distinguish between stories that crop up all the time and basically say the same thing every time ... it's not bad to be reminded about things that do seem to be the case."
  (05:11, David Spiegelhalter)

• He warns that new, contradictory studies draw more media attention even when they should be eyed with skepticism:

  "If one study goes against the mass of evidence that's previously been published, there's good reason to doubt that study. But that's the very study that gets all the publicity ..."
  (05:11, David Spiegelhalter)

Memorable Moment

• Spiegelhalter humorously confesses:

  “… he’s going to eat more fish in the future, but who's also confessed to be harbouring some tasty looking sausages in his freezer.”
  (05:52, Tim Harford)

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Main Topic 2: Who Are the World's Largest Employers?

Debunking the NHS Myth (05:52)

• The NHS is often claimed to be the "third biggest employer in the world," but that's not quite true.

The Actual Rankings (06:21-07:41)

• Ruth Alexander helps clarify the top five:
  • 5th: NHS – 1.7 million employees
  • 4th: McDonald's – 1.9 million employees (mostly franchisees)
  • 3rd: Walmart (US) – 2.1 million
  • 2nd: People's Liberation Army (China) – 2.3 million
  • 1st: United States Department of Defense – 3.2 million
• Discussion of how these numbers are counted; for example, McDonald's figure mostly includes franchise workers "wearing the uniform" but technically employed by other companies.

Nuances in Counting (07:57)

• Harford points out differences in accounting for civilian staff (e.g., US Dept. of Defense includes many civilians; China’s figure does not).

The Rest of the Top Employers (08:18-08:41)

• 8th: Indian State Railway – 1.4 million
• Hon Hai Precision Industry (Foxconn) – known for assembling iPhones and PlayStations, is 10th.

Suicide Statistics Context at Foxconn (08:41)

• Despite headlines, Foxconn's suicide rate is lower than China's national average:

  “Suicide rates in China have been put at 15 per hundred thousand people. The controversial Foxconn factory employs 400,000 people. Ten suicides per 400,000 people isn’t unusually high. I’m afraid it’s unusually low.”
  (08:46, Tim Harford)

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Notable Quotes

• On lifetime risk and daily choices:

  "That one year off our life ... is equivalent to losing half an hour a day."
  (03:19, David Spiegelhalter)

• On the challenge of scientific studies in the media:

  "People say, 'oh, well, scientists say one thing and then they say another. They can't make up their minds, why should I believe anything?'"
  (05:11, David Spiegelhalter)

• On media and statistical understanding:

  "One study goes against the mass of evidence ... that's the very study that gets all the publicity ... "
  (05:11, David Spiegelhalter)

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Key Takeaways

• Risk increases reported in media headlines (like 13% for red meat) often sound more alarming than their practical impact. For a 40-year-old, it equates to living, on average, 79 years instead of 80.
• Causation is not proven; these studies show correlation. The best evidence comes from consistent findings across many studies, not one-off headlines.
• NHS is among the largest employers globally, but is not third as often claimed—counting methods and definitions matter.
• Dramatic media headlines can misrepresent numbers, such as Foxconn suicide statistics; broader context is vital.

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Timestamps at a Glance

• 00:01-01:54: Introduction, overview of headlines about red meat death risks.
• 01:54-03:05: David Spiegelhalter explains the real meaning of “13% increased risk.”
• 03:19-03:47: Translating life expectancy loss into daily terms.
• 03:47-05:11: Correlation vs causation; statistical controls; why consistent findings count.
• 05:11-05:52: The nature of media reporting on health studies.
• 05:52-08:41: World's largest employers, how rankings are determined, and debunking the NHS myth.
• 08:41-08:46: Foxconn suicide stats in context.

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This episode is an engaging, thought-provoking look at how to interpret risk in both health research and headline-driven news, delivered with Tim Harford's signature wit and clarity. It’s a must-listen for anyone who wants to better understand the real story behind the numbers.

Transcript

[Tim Harford]

Thank you for downloading from the BBC. For details of our complete range of podcasts and our terms of use, go to bbcworldserveys.com podcasts. You're listening to a download from the BBC. This is more or less the mathematical icing on the cake of life. We make an edition of the program for BBC Radio 4, but this is a download of a special edition broadcast on on the World Service. Hello and welcome to More or Less on the BBC World Service. We're your weekly guide to the numbers in the news and in life. And I'm Tim Harford. This week, which are the world's largest employers, we set the record straight. But first, are you at risk of death by burger? Yes, you are. According to headlines around the world this week, red meat increases death. Red Meat Death Study. A hot dog a day raises risk of dying. These headlines were inspired by research at the Harvard Medical School. The Harvard researchers have studied the diets and health of more than 120,000 people over the course of more than 20 years and concluded that red meat is associated with an increased risk of fatal heart disease and terminal cancer. Indeed, they say that over the study period, an extra portion of unprocessed red meat was associated with an overall 13% increased risk of death. An increased risk of death, in the words of one of our. I'd conservatively place my risk of death at 100%, but does this mean it's actually 113%? Well, helpfully, we know a professor whose job is to improve the public understanding of risk, David Spiegelhalter of the University of Cambridge. He says the scientist's report itself is pretty technical and difficult to understand. But he, he offered to translate.

[David Spiegelhalter]

Their findings mean that if there were two men, say, aged 40, and they were really the same, they had the same weight and the same job and the same exercise, but the only difference is that one ate an extra portion of meat every day. So let's say two friends and one of them every lunchtime had a hamburger and the other didn't. Now, what they found is that the one who likes the meat has a 13% extra risk of dying each year. They're both going to die in the end, but one's got this extra annual risk of dying.

[Tim Harford]

But it's not easy to say what this might mean in practice. You might reckon that since those hamburgers increase your annual risk of dying by 13%, they might also cut your life expectancy by about 13%, say, from 80 years to 70. Or maybe not. The maths here are Hardly obvious. And you can search the research paper in vain because it won't explain this either. But Professor Spiegelhalter has worked it all out so that you don't have to.

[David Spiegelhalter]

The person who eats more meat is expected to live one year less than the person who doesn't eat so much meat. The 40 year old who does eat the meat, you'd expect, on average, him to live to 79. And the person who doesn't eat so much meat, you expect him to live till 80.

[Tim Harford]

So all those headlines, and it turns out we're talking about whether you're going to live to 79 or to 80. Maybe I'm willing to sacrifice that year in order to enjoy a life full of roast beef and steak sandwiches, but David Spiegelhalter would have me think again.

[David Spiegelhalter]

That one year off our life between age 40 and 80, that's equivalent to losing half an hour a day. So that means that the meat eater, on average, when he's sitting eating his burger, is losing half an hour of life because of that meal. On average, it's equivalent, you know, scaled up over a lifetime of smoking two cigarettes, for example, is about half an hour of your life, or being a bit overweight. 5 kg overweight, which I am. I'm 5 kg overweight.

[Tim Harford]

Which is why the professor had been out running around the park with his dog Daisy just before that interview. So perhaps I'll go easy on the bacon sandwiches, particularly since the health risk figures are even higher for bacon and other processed meats. But should we believe the findings of this study? Does eating red meat and processed meat cause cancer and cardiovascular disease and shorten life? Well, no, we can't say there's cause and effect here. All that can be said is that there appears to be a strong correlation between eating this kind of meat and having those health problems. That means we can't rule out the possibility that eating red meat is perfectly healthy in itself, but is correlated with some hidden health risk. The researchers at Harvard couldn't run a randomised controlled trial where half the participants ate burgers for two decades and the other half didn't. But they could use statistical techniques as the next best thing. They statistically controlled for a wide number of other potential risk factors, such as alcohol consumption, calorie intake, activity levels and family history of cancer. The link between red meat and cancer may still be a coincidence if there's a risk factor the researchers didn't think of, but they've certainly tried to rule that out. And these findings chime with those of Other studies, but of course that's one of the reasons people don't want to take notice. We're forever being told that what we do eat and drink causes cancer. But Professor Spiegelhalter says we should listen when the message is consistent.

[David Spiegelhalter]

I think you need to distinguish between stories that crop up all the time and basically say the same thing every time, which is what stories like this tend to, which must be a bit monotonous to hear, but, you know, it's not bad to be reminded about things that do seem to be the case. One of the problems is, of course, that what tends to get in the news is when a story comes up that's different from what people have heard before. Now, that's, I think, is really dangerous because people say, oh, well, scientists say one thing and then they say another. They can't make up their minds, why should I believe anything? And yet, actually, it's just one study. And if one study goes against the mass of evidence that's previously been published, there's good reason to doubt that study. But yet that's the very study that gets all the publicity from the media.

[Tim Harford]

Professor David Spiegelhalter, who says he's going to eat more fish in the future, but who's also confessed to be harbouring some tasty looking sausages in his freezer. Now, the National Health Service in England is at the centre of a big political row about its reform. Critics of the NHS say it's bloated. Indeed. It's often said to be the third biggest employer in the world, after the Chinese Red army and the Indian State Railway.

[Ruth Alexander]

That's an incredible claim given how much smaller the UK is than China or India.

[Tim Harford]

Hello, Ruth. Yes, I would hope it's literally incredible because it's not true. We've been sizing up the world's biggest employers and we've found the NHS isn't the world's third largest, but it is

[Ruth Alexander]

the fifth, with 1.7 million employees just sneaking ahead of the China National Petroleum Corporation.

[Tim Harford]

Come on, Ruth, give us the rest of the top five.

[Ruth Alexander]

Alright, then. At number four is McDonald's with 1.9 million employees.

[Tim Harford]

Hang on a moment, I thought most McDonald's restaurants were franchises.

[Ruth Alexander]

Yes, 8% of them are actually, which means that one and a half million workers are actually employed by different companies, but they wear the uniform. And if push came to shove, I reckon they could probably take on the Chinese Army. At number three is the Walmart supermarket chain in the US, with 2.1 million staff. At number two is the People's Liberation army of China with 2.3 million employees. And at number one, it's not the Indian State Railway with 3.2 million employees, it's the United States Department of Defense.

[Tim Harford]

So, in fact, it is almost true. I mean, McDonald's arguably doesn't count, which makes the National Health Service the world's fourth biggest employer. And it is, in fact, bigger than the Indian State Railway.

[Ruth Alexander]

You're right, Tim, but this isn't just about the nhs. I wanted to know the largest employer in the world. And. And now I do.

[Tim Harford]

I hate to rain on your hit parade, but you're comparing the army in China with the whole of the US Department of Defence. That's going to include many thousands of civilian administrative staff. You're not comparing like with like.

[Ruth Alexander]

Well, that's just the way the two countries do their counting differently. If the Chinese army counted all its civilian support staff, you're right, it would maybe shoot up into first place and

[Tim Harford]

put me out of my misery. Where does the Indian State Railway sit?

[Ruth Alexander]

Well, it's still a big employer, but it's in eighth place with 1.4 million employees, behind the State Grid Corporation of China and ahead of the Indian Armed forces. And in 10th place, Hon Hai Precision Industry.

[Tim Harford]

Hon Hai Precision Industry, better known as Foxconn. The manufacturers of well known products like the Apple iPhone and the Sony PlayStation.

[Ruth Alexander]

Yes, and it became notorious a couple of years ago when News spread that 10 of its workers had committed suicide.

[Tim Harford]

Which is tragic. But while headlines were created, this isn't the shockingly high number it seemed. Suicide rates in China have been put at 15 per hundred thousand people. The controversial Foxconn factory employs 400,000 people. 10 suicides per 400,000 people isn't unusually high. I'm afraid it's unusually low. If there's a statistic you'd like us to investigate, please email More or [e-mail] and you can download our podcasts, past and present, via our website, bbcworldservice.com more or less until next week from Ruth Alexander and from me. Goodbye. More or Less was presented by me, Tim Harford, the Financial Times undercover economist. The producer was Ruth Alexander and the editor, Richard Varden. There are dozens of different podcasts now available from the BBC, including news, documentaries, science, business, arts and sport. The details of them all go to bbcworldservice.com podcasts.