M&S ban trans fats

Marks and Spencer have responded to growing concerns about the safety of trans-fatty acids (TFAs) - man-made fats used in everything from biscuits and spreads, to chips and ready meals - by banning foods that contain them.

Trans-fatty acids are a prime example of the dangers of tinkering with nature. They are produced by heating vegetable oils to alter their chemical structure to improve their longevity and texture (TFAs are solid at room temperature and mimic that melt-in-the-mouth quality of animal fats like butter), a process known as hydrogenation and which converts relatively healthy fats into very dangerous ones.

TFAs increase blood cholesterol levels, and shift the balance of good and bad cholesterol in favour of the latter, encouraging deposition of fat in artery walls leading to the narrowing responsible for stroke and heart disease. The Harvard School of Public Health estimate that at least 30,000 Americans die from premature heart disease as a direct result of eating TFAs - equivalent to around 5,000 people a year here in the UK.

We would all benefit from cutting back on the amount of fat in our diet but using synthetic fats in everyday foods, including spreads marketed as healthier alternatives to butter, makes it difficult for consumers to make an informed choice.

Products are often labelled as low in harmful "saturated fats" like butter, but their TFA content will rarely be flagged up, and even if it is it often disguised under another name - check for trans fats, hydrogenated, or partially hydrogenated vegetable oils, vegetable shortening and margarine.

To be fair, the food industry has been trying to clean up its act - both in terms of TFA content and clearer labelling - but there is still a lot of room for improvement. The stance taken by M&S will increase the pressure on manufacturers, but major retailers like Tesco and Sainsbury's need to follow suit if we are to remove man-made fats like these from our diet.

I generally disregard most food scares but have always been wary of TFAs and won't feed them to my family if I can avoid them. During the 1990's we even stopped using spreads that contained them and went back to butter. It's not particularly good for your arteries either, but, assuming you use spreads sparingly, it makes little or no difference to your long-term health which one you go for, so you might as well use one that is natural, tastes good and contains no synthetic TFAs.

Special cholesterol lowering spreads Benecol and Flora pro Activ are an important exception - they need to be used fairly liberally to exert any beneficial effect but their cholesterol lowering ingredients more than compensate for the tiny amounts of TFA they contain.

For more information on the dangers posed by trans-fatty acids and what you can do, other than shop at M&S, to reduce your intake visit www.tfx.org.uk or www.bantransfats.com