Heres the advice from Dr Gillian McKeith's You are what you eat........
COLOURINGS
A dangerous class of additives and one of teh easiest to advoid are teh dyes capable of interacting with & damaging your immune system, Speeding up the ageing and even pushing you in the direction of cancer, steer clear of foods which are made from artificial colours. Watch out for lables with any of the following: artificial colour added, the words green, blue or yellow followed by a number, colour added with no explanation, such as tartrazine(E102), Quinoline yellow(E150), Sunset yellow(E110), Beetroot red(E162), Caramel(E150) or FD and C red no 3.
Some foods contain natural colours obtained from plants and these are safe. The most common is annatto, from teh reddish seed of a tropical tree, annatto is often added to cheese to make in more orange or butter to make it more yellow. Red pigmants obtained from beets, green from chlorella and carotene from carrots are also okay.
PRESERVATIVES
The main function of preservatives is to extend a foods shelf life. Citric acid and ascorbic acid (vitamin C, ascorbates, E300-4) are natural antixidants added to a number of foods and they are safe, but synthetic additives such as BHA and BHT(E320-21) may not be. They may promote the carcinogenic changes in cells caused by other substnces.
Alum, an aluminium compound is used in brands of many pickles to increase crispiness and is also found in some antacids and baking powder. Aluminium hs no place in human nutrition and you should avoid ingesting it. Nitrates(Nitrates, E249-52) are a type of preservative often added to processed meats, such as hotdogs, bacon and ham. They can create highly carcinogenic substances called nitrosamines in the body. It is best to avoid any product containing sodium nitrate or other nitrates. Monosodium glutomae (MSG or 621) - a natural product used in East Asian cooking - is added to many manufactured foods as a flavour enhancer. It is an unnecessary source of additional sodium in the diet and can cause allergic reactions. Omit MSG from recipes, dont buy products containing it and when eating chinease request that food is made without it. Other flavour enhancers and preservatives to avoid include monopotassium glutamate(622) and sodium osinate(631) and benzoic acid and binzoates (E210-9) found in soft drinks, beer and salad creams.
EMULSIFIERS, STABILIZERS AND THICKENERS
These are often found in sauces, soups, breads, biscuits, cakes, desserts, ice cream, margarine and other spreads, jams, chocolate and milk shakes. More & more manufacturers are cleaning up their products as people get more concerned about toxins in their food and you will increasingly see 'no artificial sweetners' or 'no artificial ingredients'. This is helpful, but watch out for hidden fats, salts & sugars & alternative names for foods that arnt very good for you when eaten in excess. Sugar, for example has lots of different names and they include: Sucrose, fructose, deztrose, corn syrup, maltodextrin, golden syrup and so on. Soudium is just another name for salt. Animal fatis saturated fat and transfatty acid is another name for hydrogenated fat. mannitol, sorbitol, xylitol, saccharine and aspartame are alternative names for potentially carcinogenic artificial sweetners. Some chemicals are harmless for instance ammonium bicarbonate, malic acid, fumaric acid, lactic acid, lecichin, xanathan, guar gums, calcium chloride, monocalcium phosphate and monopotassium phosphate. But how cah you tell when there are a long list of long chemical names that look unfamiliar to you? If thats teh case a good genural rule is simply to avoid products whose chemical ingredients outnumber teh familiar ones.
Please excuse spelling - my typing skills are not what they used to be