They can increase the risk of fertility problems by 70 per cent or more. Eating as little as one doughnut or a portion of chips a day can have a damaging effect.
Scientists at the Harvard School of Public Health in Boston did a study of 18,500 women trying to conceive and found 438 cases of ovulatory problems. Based on those results they have advised women who want to have a baby to avoid the fats, known as trans fats.
They are used in thousands of processed foods, from chocolate to pies, as well as take-away meals. They have no nutritional value but are included simply to extend the shelf life of food. It is very difficult to know the precise amount of trans fats in any food as it does not have to be put on the label.
