 | | | | |  | An antidote to panics based on dodgy statistics and dubious arguments.
Edited by Rob Lyons. |  | | |  |  |
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| | | 2 March 2006 | Child obesity
Panic: A new report by three British official bodies has criticised the government for a lack of progress on tackling child obesity. For example, it has taken 18 months just to agree on how obesity should be measured. The report quotes statistics suggesting that the proportion of obese children has risen from 9.6 per cent in 1995 to 13.7 per cent in 2003. By 2010, the report says that the cost of treating diseases caused by obesity across the whole population - including hypertension, heart disease and type 2 diabetes - will reach £3.6billion per year. Steve Bundred, chief executive of the Audit Commission, said: 'If the trend continues, this generation will be the first for many decades that doesn't live as long as their parents.'
Don't panic: While it is true that certain diseases are more common in obese adults, the vast majority of people can still expect to live into old age whatever their body shape. If fears about obesity are overstated for adults, they are even more misplaced when it comes to children.
It is by no means certain that children who are fat will go on to be fat adults. Figures suggest about 30 per cent of obese children stay that heavy in adulthood. Telling a child that being overweight means they are effectively sick may have some impact on their waistlines but is likely to be a recipe for misery in years to come. As Dr Dee Dawson, a specialist in treating eating disorders, notes: 'We should not be getting children obsessed about what they eat, how much fat and calories there is in their food, how they look. Most of them are perfectly fit and well.'
Nor are the alternatives necessarily much better. While getting some exercise, like walking regularly, seems to be beneficial, taking a lot of exercise may have little additional benefit. Dieting is not only regularly unsuccessful, but has itself been associated with health problems. As an editorial in the New England Journal of Medicine noted in 1998, 'Until we have better data about the risks of being overweight and the benefits and risks of losing weight, we should remember that the cure for obesity may be worse than the condition'.
The most controversial idea, quoted regularly, is that children of this generation will have a lower life expectancy than their parents. While not impossible, it seems highly unlikely. Firstly, it assumes that obesity is the reason that very fat people tend to die younger, rather than lack of exercise, poverty, poor quality of diet or a host of other reasons. Secondly, it suggests that this one lifestyle factor could overcome the effect of all the other medical and social developments which have provided consistent rises in life expectancy. For women, life expectancy has risen every decade for the past 16 decades, and for both sexes lifespans are rising by roughly two years every decade.
If we are really concerned about child obesity, we should stop fretting about what children eat and give them more opportunity for active, independent play. However, given our increasingly risk-averse approach towards kids, there's fat chance of that.
Read: |  | Child obesity targets could fail, | | Daily Mail, 28 February 2006 | | Why be paranoid about puppy fat?, | | by Mick Hume | | Health expectancy, | | National Statistics Online, 22 July 2004 |
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| | | 2 March 2006 | Benzene and soft drinks
Panic: 'Cancer chemical found in drinks' reports BBC News. The Food Standards Agency found that some soft drinks that contained both the preservative sodium benzoate and ascorbic acid (vitamin C) has traces of a carcinogen, benzene, formed when these two ingredients reacted together. Some drinks in the UK contained up to eight parts per billion of benzene, even though the EU standard for drinking water is one part per billion. Dr Andrew Wadge of the Food Standards Agency said: 'The levels found so far are not a cause for concern. Let's have further investigations and regular discussions with the drinks industry and check what's happening. If levels are high then the FSA will take action to protect consumers.' The food pressure group Sustain has called for tighter regulations saying 'the scientific evidence is unclear about whether there is any safe level of benzene'.
Don't panic: Benzene may be a carcinogen in large enough quantities, but the old adage 'the dose makes the poison' needs to be remembered. At such low doses, even a deadly poison would be harmless.
To get a sense of just how harmless, let us imagine that it was cyanide in those cans. The lethal dose of hydrogen cyanide (as used by Hitler, Eva Braun et al) is just 50 milligrams. However, to get that dose from drinks with a concentration of eight parts per billion, you'd need to drink over 6,000 litres - or about 18,000 cans. Benzene is nothing like as poisonous as cyanide. The irony is that, in our health obsessed days, the cause of the 'problem' is the adding of vitamin C to soft drinks.
If, as the FSA suggests, there is no risk to the consumer, why publicise these test results in the first place? As the debacle of the Sudan-I scare illustrated, it seems the FSA would rather cause an unnecessary panic than be seen to be covering up negative tests. This latest scare about soft drinks suggests it would be better if the FSA learned when to can it.
Read: | | Cancer chemical found in drinks, | | BBC News, 1 March 2006 |
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| | | 2 February 2006 | Red meat and cancer
Panic: 'Red meat cancer risk clue found,' says BBC News reporting on a new study which suggests a mechanism by which eating beef, pork and other red meat might increase the risk of bowel cancer. A small group of volunteers were fed three different diets: one in high in meat but low in fibre; high meat and high fibre; and no meat. Those in the high meat, low fibre group had significantly greater damage to the DNA in their colon than the other groups. The researchers, from the Dunn Human Nutrition Group and the Open University, suggest that N-nitrosocompounds, substances formed in the gut after consuming red meat, may be responsible.
This study follows a report published in 2005 that suggested that those who ate red meat twice a day were a third more likely to develop bowel cancer than those who ate red meat less than once a week. Cancer of the bowel causes 16,000 deaths in the UK each year.
Don't panic: This new study is only suggestive of a possible cause for why red meat might cause cancer. The link is far from proven, and if there is an increased risk it would appear to be small.
The study obliged volunteers to eat 420g of red meat each day for two weeks. That is an unusually large quantity of meat - roughly equivalent to eating four quarterpounders a day. Moreover, the small number of subjects involved and the short timescale suggest more work is required.
Even if this mechanism suggested was to be confirmed, the risks are still small. The 2005 study found that the annual risk of bowel cancer at the age of 50 for the high meat consumption group was 0.17 per cent, compared to 0.12 per cent for the low meat consumption group. Either way, bowel cancer is not a major threat for most people. While such figures translate into large numbers at a population level, they are fairly meaningless as a guide to individual behaviour.
Other factors are important, particularly age - 80 per cent of bowel cancers occur in people over the age of 60 - and survival rates have improved a lot in the last few years. So, chances are you can carry on scoffing the bacon sandwiches and beefburgers, and still live to a ripe old age.
Read: | | Red meat cancer risk clue found, | | BBC News, 31 January 2006 |
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| | | 17 January 2006 | Diet and mental illness
Panic: 'Why what we eat has led to rise in mental problems', says the Daily Telegraph, reporting a new study prepared by the food campaign group Sustain and the Mental Health Foundation (MHF). The report surveys research on the effect of various nutrients and foods on mental development and illness. The report suggests that industrialised farming and changing patterns of eating may be leading to the loss of vital nutrients and imbalances which can effect brain formation, concentration and memory. The suggestion is that rising levels of attention-deficit hyperactivity disorder (ADHD), schizophrenia and Alzheimer's may all be related, in part, to diet.
Don't panic: Coverage of the Sustain/MHF report has been much more definitive about the conclusions drawn than the report itself. At the very start, the author notes that it is not a systematic review of the literature and that there is a distinct bias towards studies that show a link between diet and mental health. So, the author suggests the report should not be read as a definitive statement on the science, but as an awareness-building exercise. 'Advocacy research' might be nearer the mark.
Even some of the basic assumptions need to be called into question. It is far from clear that there has been a real increase in mental health problems over the last few years. In a society increasingly obsessed with health and the inability to find a wider meaning to life, many behaviours previously regarded as normal variations of personality are being redefined as mental illness. Moreover, if there has been any increase in mental health problems, those same navel-gazing trends must be a prime candidate as an explanation. Increasing levels of drinking, drug-use and the decline of traditional patterns of family and working life could all represent a stronger explanation than our failure to eat enough oily fish.
In the foreword, Professor Tim Lang of City University makes the analogy with heart disease and diet. The heart disease-diet link is well-established now, he suggests, and the mental health-diet link must surely follow. In reality, while our diets are allegedly getting worse, death rates from coronary heart disease for those under 75 have tumbled in the past 30 years. Far from confirming his case, the analogy only illustrates how 'common sense' explanations of ill-health need to be treated with caution.
Still, the provisional nature of the research hasn't stopped Sustain from packing the report's recommendations with their own particular hobby-horses. For example, 'All prison facilities should instigate sustainable food policies and practices so that all residents and staff are encouraged to choose culturally diverse and appropriate meals, snacks and drinks that promote their mental, emotional and physical wellbeing.' What have cultural diversity and sustainability got to do with whether we getting enough selenium or iodine in our food?
It is true that at a fundamental level, 'we are what we eat' - but we are much more than the sum of the nutrients that make up our bodies, and our minds are much more than the chemical make-up of our brains.
Read: | | Changing Diets, Changing Minds: how food affects mental health and behaviour, | | Sustain, 16 January 2006 |
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| | | 6 January 2006 | BBQs and climate change
Panic: 'Warm weather "to boost food bugs"' reports BBC News after comments from public health expert Professor Paul Hunter of the University of East Anglia. 'There's an interesting area around climate, that's how is it going to impact on human behaviour', said Hunter. 'People have more barbecues when it's hot.' In turn, this would lead to food being left out or undercooked more often with a resultant increase in illness. His comments were echoed by Gordon Nicholls from the UK Health Protection Agency who suggested that cases of malaria might appear in the UK, too.
Don't panic: It is still unclear what, if any, long-term impact global warming might have on the UK, but that won't stop the relentless speculation about how climate change is going to make life worse.
Assuming that Professor Hunter is right and the UK does get warmer weather in future, it is interesting how he manages to turn this into a Bad Thing. Most Britons look enviously at Americans and Australians enjoying outdoor get-togethers with beer and grilled meat. In fact, if anything is likely to cause food poisoning, it is the fact that barbecues in the UK are so few and far between. Rushing outside with inadequately defrosted burgers and chicken to take advantage of the unexpected surprise of some weekend sun, the catchphrase at every British barbecue is, 'Does anybody know how to light it?' It's a miracle that there aren't more cases of food poisoning. If we could actually rely on there being good weather, we might barbecue more often, and learn how to do it properly.
The idea of malaria making a comeback because of rising temperatures seems implausible. Many parts of Western Europe have climates which are hotter than the UK will ever get, yet endemic malaria was officially eradicated 30 years ago (and much earlier in the majority of countries). As Paul Reiter points out, 'From 1564 to the 1730s - the coldest period of the Little Ice Age - malaria was an important cause of illness and death in several parts of England'. The prevalence of malaria is related above all to economic development, not temperature. Better drainage, improved healthcare and the use of pesticides are among the main factors that have enabled developed countries to conquer the disease.
To suggest that an increase in average temperatures might have pros as well as cons is at odds with the consensus that the future is bleak because human beings damage or destroy everything they touch. But while the science of climate change is complex and provisional, 'manmade global warming' is a morality tale about the dangers of messing with nature. If islands drowning under rising sea levels or crops failing are too remote to scare you, perhaps the thought of uncontrollable vomiting and diarrhoea will make you reconsider that 4x4 you were going to purchase.
We should not take the ideas of 'experts' like Hunter at face value. It's not just those barbecue steaks that need a good grilling.
Read: | | Warm weather 'to boost food bugs', | | BBC News, 4 January 2006 | | From Shakespeare to Defoe: Malaria in England in the Little Ice Age, | | by Paul Reiter, Emerging Infectious Diseases, Jan-Feb 2000 |
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