This week Sir Simon Stevens, chief executive of the NHS, Jamie Oliver, well know chef and the editor of the Times have all come out in favour of a tax on sugary drinks. Why, what is the evidence?
In July this year Cambridge researchers analysed 17 studies in this area which suggested that an intake of sugary drinks a day increased the risk of diabetes even in slim people.
One of the best trials, a very large European cohort study based at Imperial College London showed a strong link between developing type 2 diabetes and sugar sweetened drinks such as cola. Even one glass had a substantial effect. However artificially sweetened drinks such as diet coke and fruit juices did not lead to an increase. This was a large, well designed study of over 300,000 people for 16 years. Participants also completed questionnaires on other factors that could influence results including smoking, alcohol, physical activity and educational level and BMIs. The researchers used standard statistical methods to analyse the association between soft drink consumption and diabetes. They then adjusted their results for confounders such as lifestyle factors and BMI.
Consumption of sugar-sweetened drinks may lead to type 2 diabetes because they lead to weight gain. They also have a ‘glycaemic effect‘ that can lead to rapid spikes in blood glucose and subsequent insulin secretion. This is the first major study of the effects of sugary drinks in Europe. Other studies have shown links between diabetes and sugary drinks in the USA where soaring obesity levels have caused such concern that the Mayor of New York banned soda/sugary drink portions larger than 16oz.
10% of New Yorkers are now diabetic and America is leading the way in anti-obesity adverts [see below]. However the Supreme Court overturned Mayor Blomberg’s new law as it did not ‘respect the autonomy’ of the individual to make choices. Other Public Health measure to reduce obesity levels have included the ‘fat tax’ that was introduced in Denmark that imposed a tax on saturated fat. It was found that the Danish tried to avoid it by buying butter in neighbouring countries and it was repealed but a ban on trans fats [a particularly harmful type of fat found in margarines] has been kept in Denmark and exists in most USA states.
Public Health is concerned with the health of populations. It is an extremely important part of medicine. Public health measures, such as vaccination, smoking bans, minimum price alcohol and taxes can have a massive effect on a country’s health for very little cost [an actual monetary gain if a tax is imposed.] We now live on average 15 years longer compared to the 1960’s. Average life expectancy is 80 rather than 65. It is estimated that 10 out of those 15 years has been gained simply because less people smoke now where as in the 1960’s nearly all men smoked.The contribution of modern medicine and new treatments only accounts for 5 of those years. The smoking ban in public places has been estimated to have already saved 1/2 a million lives.
The argument of upholding the autonomy of the individual against those encouraging healthier habits is centuries old. ‘Rights versus Responsibility’ is still an issue debated frequently today. It is a common ethical scenario, the unhealthy habits of other people affect us all – from second hand smoke, consequences of alcoholism to the costs of obesity for the NHS.