Q:How can I treat persistent acne (I'm 32) that seems resistant to a healthy diet, vitamin and mineral supplements, herbal remedies, aromatherapy, homeopathy and just about everything else I've ever tried? D M, Peterborough...........

A:One area you don't mention is allergies. Our panellist Dr Melvyn Werbach finds that many cases of persistent acne have to do with food sensitivities. In one study, almonds, malt, cheese, mustard, red pepper and wheat flour caused the greatest exacerbation of acne, in that order (Derma, 1978; 157 (5): 294-5. Milk has also been shown to worsen acne, largely due to its high content of progesterone or animal fat (Proc Soc Exp Biol Med, 1972; 139: 745); and chocolate has also been implicated in some, but not all cases (JAMA; 1970; 211: 1856).

Another area to experiment with is your intake of fat and carbohydrate; many populations such as eskimos and blacks from Kenya with clear, healthy skin begin developing acne when they start consuming a Western diet. Dr Werbach recommends that you try a low fat diet (particularly low saturated fats), avoid hydrogenated fats and refined carbohydrates, and consume natural vegetable oils. Sometimes a high carbohydrate diet can also exacerbate your sebum production. If altering your intake of saturated/unsaturated fats doesn't work, try cutting down your intake of carbohydrates. Supplements of folic acid, beta carotene, vitamins E and B6, zinc, selenium and omega-6 essential fatty acids have been proved helpful.

Perhaps the best approach is a combination of treatments, says Dr Werbach. In one study of nearly 100 patients, 92 per cent had good to excellent results (and nearly half had their condition clear up in two months or less), when they followed a well balanced diet, low in fat and sugars; avoided female hormones, inorganic iron and extra iodine, more than a glass of milk a day and B12, all of which aggravate acne; took 50,000 iu of water soluble vitamin A twice daily, 400 IU of vitamin E twice daily, 50 mg B6 once or twice daily; and applied benzoyl peroxide 5 per cent gel at night after washing gently with nonmedicated soap (Cutis, 1981; 28: 41-2).

As for herbs, Dr Werbach has found evidence that vitex agnus castus, gugulipids or tea tree oil applied topically, have evidence of success (M Werbach and M Murray, Botanical Influences on Illness: California: Third Line Press, 1994).

For other nutritional suggestions, see Alternatives, WDDTY vol 4 no 7).