Banning trans fats – whose nutritional value is sometimes compared to putting "melted tupperware on toast" – would save thousands of lives, researchers say today.
The UK should follow the example of New York, California, Switzerland, Denmark and Austria and implement a ban on the hydrogenated vegetable oils whose main selling point is that they are cheap, experts from Harvard Medical School and Harvard Public School of Health, Boston, US, say.
Trans fats – also known as trans-fatty acids – are found in cakes, pastries, pies, biscuits, snacks and fast foods. They are formed when liquid vegetable oil is turned into solid fat in a high temperature process called hydrogenation, and, as well as being cheap, they extend the shelf life of products that contain them.
Even a 1 per cent fall in use of the fats, as a proportion of total daily calories, would prevent an estimated 11,000 heart attacks and save 7,000 lives a year in England alone. Consumption of trans fats in developed nations ranges from 2-4 per cent of total calorie intake, they say.
In New York, voluntary efforts to reduce their use failed, but when they were banned in 2007 the proportion of New York restaurants using trans fats fell from 50 per cent to less than 2 per cent. (Some trans fats occur naturally so they cannot be totally eliminated.) Fears that trans fats would be replaced with saturated animal fat, which is also bad for health, have proved unfounded.
Writing in the British Medical Journal, Dariush Mozaffarian, assistant professor of medicine, and Meir Stampfer, professor of epidemiology at Harvard, say removing industrial trans fats is "one of the most straightforward public health strategies for rapid improvements in health".
A ban would save lives, be easy to implement yet have no impact on the price, sales, taste or availability of the affected foods, they say.
Several British supermarket chains, including Marks and Spencer and Waitrose, have phased out trans fats, as have some food manufacturers. The New England Journal of Medicine published a scientific review of trans fats in 2007 which said that "from a nutritional standpoint, the consumption of trans-fatty acids results in considerable potential harm but no apparent benefit".
The Food Standards Agency said consumption of trans fats in the UK was down to 1 per cent of total energy intake on average, half the maximum safe level recommended by the Scientific Advisory Committee on Nutrition.
The Agency reviewed the safety of trans fats in 2007, including the legal bans introduced in Denmark and New York, and concluded that saturated fat found in meat, butter and milk posed a bigger health problem because of the larger quantities consumed. Efforts should be focused on reducing consumption of saturated fats, it said.
The Food and Drink Federation said the BMJ editorial did not contain any "population intake levels" and "could give rise to unnecessary health concerns". Barbara Gallani, the federation's director of food safety and science, said: "Artificial trans fats have been virtually eliminated from processed foods in the UK.
"Intakes are at even lower levels than shown by previous surveys – reportedly 0.8 per cent – well below the recommended maximum of of 2 per cent of food energy. The UK Government has recently concluded that trans fats at these levels do not pose health risks to UK consumers, an opinion with which we concur."
Victoria Taylor of the British Heart Foundation said the reduction in trans fats was good progress. "But we still need to do more to make sure that the industrially produced trans fats don't creep back into our nation's diets."