Tuesday, September 06, 2011

Soda drinking under heavy attack

But where are the double-blind studies showing what harm it does? It's all just theory -- and wrong theories are a dime a dozen when subjected to double-blind test

Half of Americans drink a soda or sugary beverage each day - and some are downing a lot. One in 20 people drinks the equivalent of more than four cans of soda each day, even though health officials say sweetened beverages should be limited to less than half a can.

The Centers for Disease Control and Prevention released the figures Wednesday in a report said to be the government's first to offer national statistics for adults and kids.

Sweetened drinks have been linked to the U.S. explosion in obesity and related medical problems, and health officials have been urging people to cut back for years. Some officials have proposed an extra soda tax and many schools have stopped selling soda or artificial juices.

But advocates say those efforts are not enough, and on Wednesday, a coalition of 100 organizations announced a new push. The effort includes the American Heart Association and the some city health departments that plan to prod companies to stop the sale of sugary drinks on their property or providing them at business meetings - as Boston's Carney Hospital did in April. There will also be new media campaigns, like one starting soon in Los Angeles that will ask, "If you wouldn't eat 22 packs of sugar, why are you drinking it?"

The new CDC report may be ammunition. It found:

- About half the population drinks a sugared beverage each day.

- Males consume more than females, with teenage boys leading the pack. On average, males ages 12 through 19 drink the equivalent of nearly two cans of soda each day.

- Poor people drink more than the more-affluent. Low-income adults got about 9 percent of their daily calories from sugary beverages; for high-income adults, it was just over 4 percent.

- Blacks get more of their calories from sweetened beverages than other racial and ethnic groups.

The study is based on in-person interviews of more than 17,000 people in the years 2005 through 2008. They were asked to recount everything they ate and drank in the previous day. However, diet sodas, sweetened teas, flavored milks and 100 percent fruit juice did not count.

Healthy-eating recommendations call for people to limit sugary drinks to 64 calories per day. That's a little less than half of a 12-ounce can of regular Coca-Cola, which is 140 calories.

In other terms: An average can of sugared soda or juice has 10 to 12 teaspoons of sugar.

There have been efforts to reduce children's access to sodas and sports drinks in schools, with beverage companies agreeing to remove full-calorie soft drinks. But the CDC study found more than half of the drinks are consumed at home. Less than 1 percent are bought at schools or day-care centers.

That's why some members of the coalition argue that parents shouldn't drink sweetened beverages, so they don't serve as a poor example. They hope drinking soda will become as unfashionable as smoking.

A spokesman for Carney Hospital, the 149-bed Boston facility that stopped allowing full-calorie soft-drink sales, said the approach made sense. When the policy was implemented in April, sales of beverages dropped, but have gone back up, as more people apparently are adjusting to water and other non-sweetened drinks.

The hospital's Dorchester neighborhood has high rates of diabetes and other weight-related illnesses, said spokesman Joe Burnieika. "We can't afford to feed people's bad habits if we can give them a healthy alternative," he said.

In a statement, the American Beverage Association on Wednesday suggested that the coalition's effort was misguided. Citing sales data and some other research, the industry group said sales of full-calorie soft drinks had been declining, which they credited to soda makers offering more no-calorie and low-calorie options and improved calorie labeling on the front.

These initiatives "will contribute far more to solving complex health issues like obesity than (the coalition's) sound bite solution that offers plenty of hype but no substance," the statement said.


BAD SCIENCE by Ben Goldacre (Harper Perennial 2009) £12.99

Book Review by Dr. Alick Dowling.

This book is unknown to many MedChi members despite being hugely popular – it has entered the best-seller list recently. I, by chance, received a copy at Christmas from a nephew, who with his wife were fellow medical students with Goldacre in Oxford, qualifying in 1995.

The book proved an enjoyable read. Abounding with common sense as well as much combative material from his Bad Science weekly column in the Guardian, Goldacre’s aim is to correct much nonsense written by ‘scientific’ or ‘medical’ journalists that is wrong, frightens many readers and yet escapes editorial correction. His column has a large and devoted following, many of whom were at the Bath Literary Festival when Ben Goldacre spoke on March 1st 2009. Three hours earlier I had heard James Le Fanu introducing his Why Us? to his audience that Spring morning in the splendid Guildhall Banqueting Room. The review of Why Us? appeared last month on the MedChi website.

I had no thought then of doing the same for Ben Goldacre’s book. It had already reached a wide public; my only criticism would have been that it lacked an index. There are many reasons not to review a book – for example in the Spectator (May 2nd 2009) Nigel Lawson wrote: "As a general rule, I do not believe in reviewing bad books. Review space is limited, and the many good books that are published deserve first claim on it."1

My reason for not reviewing Goldacre’s book was the opposite. It is a good book and needed no more praise. When we were told the astonishing reason why a new (actually the original) version was now available I changed my mind. This includes the pivotal Chapter 10 The Doctor Will Sue You Now, omitted from the version published last year. Goldacre’s account of how this came about is lucid, revealing and gives an example of his style:
Ben Goldacre‘s website April 9th, 2009

Chapter 10 in the original book – The Doctor Will Sue You Now, on Matthias Rath was removed, together with the index, from the first published version in Sep 08.

This is the “missing chapter” about vitamin pill salesman Matthias Rath. Sadly I was unable to write about him at the time that book was initially published, as he was suing my ass in the High Court. The chapter is now available in the new paperback edition, and I’ve posted it here for free so that nobody loses out.

Although the publishers make a slightly melodramatic fuss about this in the promo material, it is a very serious story about the dangers of pseudoscience, as I hope you’ll see, and it was also a pretty unpleasant episode, not just for me, but also for the many other people he’s tried to sue, including Medecins Sans Frontieres and more. If you’re ever looking for a warning sign that you’re on the wrong side of an argument, suing Medecins Sans Frontieres is probably a pretty good clue.

Anyway, here it is, please steal it, print it, repost it, whatever, it’s free under a Creative Commons license, details at the end. If you prefer it is available as a PDF, or as a word document. Happy Easter!

You are free to copy it, paste it, bake it, reprint it, read it aloud, as long as you don’t change it – including this bit – so that people know that they can find more ideas for free at www.badscience.net

This chapter did not appear in the original edition of this book, because for fifteen months leading up to September 2008 the vitamin-pill entrepreneur Matthias Rath was suing me personally, and the Guardian, for libel. This strategy brought only mixed success.

For all that nutritionists may fantasise in public that any critic is somehow a pawn of big pharma, in private they would do well to remember that, like many my age who work in the public sector, I don’t own a flat. The Guardian generously paid for the lawyers, and in September 2008 Rath dropped his case, which had cost in excess of £500,000 to defend. Rath has paid £220,000 already, and the rest will hopefully follow. Nobody will ever repay me for the endless meetings, the time off work, or the days spent poring over tables filled with endlessly cross-referenced court documents.

On this last point there is, however, one small consolation, and I will spell it out as a cautionary tale: I now know more about Matthias Rath than almost any other person alive. My notes, references and witness statements, boxed up in the room where I am sitting right now, make a pile as tall as the man himself, and what I will write here is only a tiny fraction of the fuller story that is waiting to be told about him. This chapter, I should also mention, is available free online for anyone who wishes to see it.

The missing index is explained. This is also available on the internet for owners of the original paperback, but unless it is completely rewritten it will only be valid for the first 9 chapters. Read the missing chapter free, and then decide whether to buy the new paperback.

The Chapter Bad Stats and its precursor Why Clever People Believe Stupid Things is of particular interest to doctors – not because they can be assumed to be Clever People, but because many do not realize how easily promoters of dubious theories manipulate us to accept ‘facts’ that are cleverly presented. Older doctors, never taught statistics, are more vulnerable than our younger colleagues. Goldacre uses clarity and simple terms to elucidate the subject. Malcolm Kendrick wrote a similar account about statistics in his book The Great Cholesterol Con (also reviewed on the MedChi website). For a comparison see below.

Goldacre’s aim to make ‘science’ accessible to ordinary readers is difficult to achieve, but he has the knack of doing so. He repeats the mantra: “I think you’ll find it’s a bit more complicated than that” when exasperated by the simplistic ‘explanations’ by ‘science’ journalists and even suggests it as a T-shirt slogan for the whole book.

His chapters on other individuals (including the new extraordinary account of Rath) are riveting. Professor Patrick Holford, the academic lynchpin at the centre of the British nutritionism movement, is dealt with in Chapter 9. It is not surprising that the ‘nutritionist’ Gillian McKeith took exception to Goldacre’s exposure in Chapter 7, but someone who has survived a legal encounter with Rath can easily dismiss her threats of legal action.

Goldacre’s introduction mentions the 50th anniversary of C.P. Snow’s lecture on the ‘Two Cultures’ of science and the humanities. Then arts graduates simply ignored science. No progress apparent since, but he is perceptive in seeing there has been a positive regression: "Today, scientists and doctors find themselves outnumbered and outgunned by vast armies of individuals who feel entitled to pass judgment on matters of evidence – an admirable aspiration – without troubling themselves to obtain a basic understanding of the issues."

The structure of the book is sensible and cleverly laid out – a steady crescendo from a gentle introduction in how science should be taught, through an increasingly serious range of how we should view what we are told by ‘experts’ with suspicion, then through the milder and less dangerous forms of foolishness – homeopathy makes its appearance here – through the placebo effect, onwards to the bigger fish such as Nutritionists, the way the pharmaceutical industry pulls the wool over the eyes of doctors and patients, the misuse of statistics already mentioned and culminating in what Goldacre finds most worrying, how people in positions of great power still commit basic errors when dealing with health scares. If we disagree with him he tells us that we’ll still be wrong but with a lot more panache and flair that we could possibly manage right now.

Received from the author. The chapter about Rath -- who claimed to cure AIDS by vitamins -- is here

Two examples of statistical jiggery pokery:


Newspapers like big numbers and eye-catching headlines. They need miracle cures and hidden scares, and small percentage shifts in risks will never be enough for them to sell readers to advertisers (because that is the business model). To this end they pick the single most melodramatic and misleading way of describing any statistical increase in risk, which is called the ‘relative risk increase’.

Let’s say the risk of having a heart attack in your 50’s is 50% higher if you have high cholesterol. That sounds pretty bad. Let‘s say the extra risk of having a heart attack if you have high cholesterol is only 2%. That sounds OK to me. But they’re the same (hypothetical) figures. Let’s try this. Out of a hundred men in their fifties with normal cholesterol, four will be expected to have a heart attack. That’s two extra heart attacks per hundred. Those are called ‘natural’ frequencies.

Natural frequencies are readily understandable, because instead of using probabilities, or percentages, or anything even slightly technical or difficult, they use concrete numbers, just like the ones you use every day to check if you’ve lost a kid on a coach trip, or got the right change in a shop. Lots of people have argued that we evolved to reason and do maths with concrete numbers like these, and not with probabilities, so we find them more intuitive. Simple numbers are simple.

The other methods of describing the increase have names too. From our example above, with high cholesterol, you could have a 50% increase in risk (the ‘relative risk increase’); or a 2% increase in risk (‘the absolute risk increase’); or, let me ram it home, the easy one, the informative one, an extra two heart attacks for every hundred men, the natural frequency.

Malcolm Kendrick:

(p 192) quoting the Heart Protection Study (HPS) press release: If now, as a result, an extra 10 million high-risk people were to go onto statin treatment, this would save about 50,000 lives a year, that’s a thousand each week. Leaving aside the point that this 50,000 figure actually equates to one life ‘saved’ for every 200 taking the statin – ten million is an awful lot of people to use as your denominator – the concept of saving lives, suggesting as it does, that each of the 50,000 whose lives have been saved will go on to live a healthy life, is not best chosen.

In reality, taking a statin can only delay death, not prevent it. By how much? Well, if one in two hundred more people are alive after one year of taking statins, this means that if you wait another two-hundreths of a year (plus another little bit) the statin group will have caught up on the ‘placebo’ group in total number of deaths.

This represents an increased life expectancy of slightly under two days. So rather than stating that fifty thousand lives would be saved every year by taking statins, it would be considerably more accurate to state that if ten million people (at very high risk of heart disease) took a statin for a year they would live – on average – two days longer.

And if all ten million took a statin for two hundred years, they would all live – on average – an extra year. If we assume that most people would take a statin for thirty years maximum, this would lead to an average increase in lifespan of approximately two months.

Which doesn’t sound quite as dramatic as saving fifty thousand lives a year, or a thousand a week – or however you choose to hype up your figures. But there you go, it happens to be considerably more accurate.

Also remember that this benefit would only be seen in men with pre-existing heart disease. Women and men without pre-existing heart disease would not live a day longer. They would just have the dubious pleasure of thirty years of paying for drugs, worry and side effects.

No comments: