Saturday, November 19, 2005

Statins seem to work, but the cholesterol thesis doesn't stack up

I was very glad to see this essay by Malcolm Kendrick on spiked. The theory that our diets are killing us is usually elaborated by suggesting that eating lots of fat, or not eating the right fat, causes us to have increased cholesterol and makes us die young. However, while statins seem to have a protective effect, their action in lowering cholesterol may not be the reason (and in any event, as Ravnskov points out, mass medication is unlikely to have a huge positive benefit).

The Great Cholesterol Myth

Tuesday, November 15, 2005

A very expensive diet

'NHS picks up 6billion a year bill for our bad diet', reports today's Daily Telegraph. Researchers working in the British Heart Foundation (BHF)'s Health Promotion Group at Oxford University brought together figures on NHS costs broken down by disease, and compared them with figures from the World Health Organisation (WHO) which attribute percentages of each disease by cause. The main claim is that 'food-related ill health is responsible for about 10 per cent of morbidity and mortality in the UK and costs the NHS about 6billion annually'.

Even the researchers accept that their results are 'crude estimates', although they think they are probably reasonable. They are, nonetheless, estimates based on other estimates.

The headline figure sounds incredible until you realise that the NHS spent around 70billion in 2002, increasing to around 88billion in the current financial year. So while 6billion seems like a lot of money, it actually reflects the huge sums now spent on healthcare as much as it might be an indictment of our diets.

The figures still need to be treated with caution. They are based on WHO figures suggesting that diet contributes about 15 per cent of all life-years lost to death and disability. However, such estimates are prone to re-evaluation, as the embarrassingly massive downward revision in US obesity-related deaths earlier this year demonstrated. US health authorities produced a figure of 400,000 obesity-related deaths in 2004, but now the accepted figure is in the region of 112,000 (and lower, just 26,000, if you allow for the apparent protective effect of being overweight but not obese).

It's also worth noting that the category of '15 per cent' who die of 'bad diet' includes not just those who are overweight and obese (6.9 per cent) but also those who have a low fruit and vegetable intake (2.3 per cent) and consume a lot of saturated fats (6.4 per cent). Yet the links between ill-health and all three of these factors is much more controversial than is suggested by such bald estimates. All estimates of deaths from any lifestyle cause (smoking, eating, alcohol and so on) are produced by extrapolating risk factors from small studies, each with their own methodological problems, to whole populations. There is plenty of room for error in such an exercise.

Above all, it is laughable to suggest that all this death and illness would disappear if we all just switched to eating fruit and salads and avoided burger bars. But such news reports help groups like the British Heart Foundation to bang the drum in favour of greater levels of spending on their particular concerns.

NHS picks up 6bn a year bill for our bad diet, Daily Telegraph, 15 November 2005

The burden of food related ill health in the UK, Journal of Epidemiology and Community Health, 15 November 2005 [pdf]