According to this month's issue of Mayo Clinic Health Letter, temporarily avoiding certain foods can help identify the individual causes of flatulence, helping sufferers breathe a sigh of relief. Dairy products, vegetables, fruit sugar, fibre, sweeteners, fatty foods and carbonated drinks may all be associated with this embarrassing after-effect of eating. The sugar lactose in dairy foods is a common cause of gas, though non-prescription products may help ease the problem. Many who are bothered by dairy products may still be able to eat yoghurt or aged cheeses. Although healthy, some carbohydrates found in vegetables such as onions, radishes, cabbage, celery, carrots, brussel sprouts, broccoli, cauliflower and legumes (including dried peas and beans) may produce gas. Products have been manufactured to relieve the problem. If consumers find these foodstuffs to be the reason for excess wind, products containing simethicone may be helpful. Fruit containing large quantities of sugar could also be the culprit. The foods to watch out for are prunes, raisins, bananas, apples and apricots, as well as juices made from prunes, grapes and apples. Another cause could be too much fibre. Cutting back on high-fibre foods and then gradually increasing them can help identify the amount that can be tolerated. Avoiding fried foods, fatty meat and some sauces as well as carbonated and sparkling drinks may help reduce gas. Some sweeteners used in sugar-free chocolates and candies, such as sorbitol, mannitol and xylitol, can cause flatulence. Some food manufacturers have tried to alleviate the problem by developing foodstuffs that promise not to cause flatulence. For example, in 2006 a new variety of the flatulence-free manteca bean, grown in the UK, was developed by Dr Colin Leakey.