Experts say the right diet may be the key to treating skin disorders.

Up to 90 per cent of Australians - or 18 million people - will suffer from skin ailments at some time in their lives, including acne, eczema, skin cancer and psoriasis , according to figures from the Australasian College of Dermatologists. Almost one-quarter of children have eczema, compared with about 10 per cent a decade ago and about 85 per cent will have acne. Although most acne clears after adolescence, up to 20 per cent of adults may continue to be affected.

It is no surprise, then, that the medicated skin care market is experiencing unprecedented growth, but some practitioners believe what we put inside our bodies is more important than smearing our skin with expensive treatments. Nutritionist and author Patrick Holford says: "Your skin is affected by how well you are internally and is therefore a remarkable barometer of your overall health. Getting your body's systems working optimally is crucial to addressing skin problems. Diet is key - eating foods that nourish your body while limiting those that contribute no nutritional value is important."

Many skin conditions are thought to be a reflection of hormone imbalances and the inability to absorb nutrients and eliminate the byproducts of digestion. Helen Sher, founder of the natural skin care company Sher, says: "The majority of our clients have been on courses of antibiotics to banish spots and rosacea, but this is not a long-term solution." She points out that antibiotics kill good bacteria as well as bad, which can damage the digestive and immune systems.

In the case of rosacea (an inflammatory condition that affects 45 million people worldwide, in which the face becomes flushed and itchy), there is evidence that many sufferers produce insufficient stomach acid and the resultant incomplete digestion of food is the main factor.

If skin disorders are the body's way of expressing its imbalances, then treating a skin problem using topical creams and gels is the equivalent of applying a hot flannel to the tip of an iceberg. Robin Logan, author of The Homoeopathic Treatment Of Eczema, explains why it is important to view the body as a whole: "Suppressing eruptions [topically] can lead to the development of more serious internal complaints. This is typically seen in the eczema/asthma syndrome."

According to Michael Franklin, founder of Britain's Allergy and Nutrition Centre, food allergies play a considerable part in many skin complaints. "Psoriasis is usually extremely difficult to treat, yet if more patients and practitioners knew of the links with bowel toxicity, there would be fewer problems. Liver detoxification is an important part of treatment. With rosacea, a lack of B vitamins may play a role."

Not everyone subscribes to the idea of treating your biggest organ from the inside out. Nina Goad, of the British Association of Dermatologists, says: "In general, diet has little influence on skin, though there are a few exceptions. Alcohol and spicy foods seem to make rosacea worse.

"As for acne, there is some evidence that foods with a high glycaemic index [which measures the effects of carbohydrates on blood glucose levels] may worsen the condition in some people."

What to avoid

Dr Jonathan Wilkin, of Britain's National Rosacea Society, says foods that might trigger flare-ups include liver, yoghurt, cheese (except cottage cheese), chocolate, vanilla, vinegar, spicy foods, coffee or tea.

The most documented reactive foods for eczema sufferers are milk, eggs, peanuts, soybeans, wheat, seafood and seeded fruits. Nutritionist Patrick Holford suggests that with skin complaints you should limit your intake of sugary foods, refined carbohydrates (such as white bread) and anything fried.

What to eat

The skin is the last place nutrients will arrive after they have serviced the rest of your body so it is vital to get enough of the things we know help the skin to heal and regenerate.

Proper hydration is vital to a healthy system. Helen Sher recommends drinking six or seven glasses of water daily. Vitamins C and E are important for skin health - mainly as antioxidants - so include organic fruits and vegetables in your diet, especially black grapes and blueberries. Apricots, oranges, peppers, carrots, strawberries and broccoli are rich in the carotenoid pigments, which your body converts to vitamin A.

Nutritionist and author Michael van Straten says: "Carrot juice is bursting with beta carotene; one glass a day, fresh if possible, works wonders for the skin and is a powerful antioxidant."

The naturopathic nutritionist Charlotte Fraser suggests increasing your intake of essential fatty acids to help treat dry skin conditions and acne. Eczema and psoriasis sufferers will benefit from the anti-inflammatory effect of omega 3 found in oily fish.

Evening primrose oil is a source of gamma linoleic acid, which promotes healthy skin, hair and nails.

The most important B vitamin for the skin is biotin, which is found in bananas, eggs and rice. Zinc deficiency can be a factor in psoriasis and acne. Good sources of zinc are sesame, sunflower and pumpkin seeds.

有专家认为，合理的饮食是治疗皮肤问题的关键。

澳大利亚皮肤病专科学院的调查数字显示，近90%的澳洲人（-约180万人）-一生中都曾为各种各样的肌肤问题所困扰，比如说痤疮、湿疹、皮肤癌和牛皮癣。大约四分之一的儿童患湿疹，与十年前10%的比例相比，痤疮患者的比例达85%。尽管大多数痤疮症状在青春期之后就会慢慢消失，但是近20%的成年人仍然被其困扰。

因此，药物护理产品的走俏也就不足为奇了。但是一些医师认为，内部的调理比用高档化妆品涂抹更重要。营养学家作者帕特里克·霍夫德说：“你体内的环境决定你的皮肤状况，你的皮肤就像你健康情况的晴雨表。调整你的内循环是解决肌肤问题的关键。饮食至关重要-要注意多吃有营养的食物，控制垃圾食品的摄入量。”

很多的皮肤问题都被认为是荷尔蒙失调、吸收不好及代谢问题导致的。自然肌肤护理公司的创始人海伦·谢尔说：“我们大多数的客户都曾使用过抗生素怯斑除痘，但是这并不能解决根本的问题。”她指出，抗生素在杀死细菌的同时也会杀死有益菌，会影响人体的消化系统和免疫系统。

以红斑痤疮（一种影响全球4500万人的肌肤炎症，患者皮肤会发红发痒）为例，经证实，大多数红斑痤疮患者的主要病因都是胃酸不足和消化不良。

如果肌肤是体内系统失调的表现，靠使用眼下流行的各种面霜和凝胶来解决肌肤问题无异于雪上加霜（加热的法兰绒放到冰山角上）。《湿疹顺势疗法》一书的作者罗宾·罗格阐释了全面关注身体的重要性：“抑制出疹（当前流行的办法）只会使其内部更加恶化，湿疹/哮喘综合症的表现更明显。

根据英国过敏和营养衷心的创始人米歇尔·富兰克林认为，食物过敏与所多肌肤疾病也密不可分，“牛皮癣难治愈，但是如果患者和医师了解牛皮癣和患者肠内毒素的关系的话，问题就简单得多了，治疗牛皮癣有效的方法是驱除肝脏内的毒素。对于红斑痤疮患者来说，可能是因为缺乏B族维生素。”

并不是每个人都认为皮肤病是由内因导致的。英国皮肤病协会的妮娜·戈尔德认为：“一般说来，饮食对皮肤的影响并不大，尽管也有些特例。酒精和刺激性食物也会使红斑病情加重。”

“至于痤疮，有证据显示含高血糖指数（衡量血液葡萄糖中碳水化合物作用情况的指数）可能会使某些患者的病情加重。”

饮食禁忌

英国国家红斑痤疮协会的约翰逊·威尔金博士认为，肝脏、酸奶、奶酪（松软干酪除外）、巧克力、香草、辛辣刺激食物、咖啡或茶都可能引发皮肤问题。

湿疹患者应注意不要食用牛奶、鸡蛋、花生、大豆、小麦、海鲜和有籽果 ，营养学家帕特里克·霍夫德建议皮肤病患者注意不要摄入太多含糖的食物，精炼碳水化合物（如白面包）以及煎炸食品。

饮食贴士

肌肤是营养输送的最后一站，营养在到达全身其他部位后才轮到肌肤。因此，补充足量的物质以促进肌肤的恢复和再生就显得至关重要。

健康系统需良好的水和作用。海伦·谢尔女士建议每天饮用6-7杯水。维生素C和维生素E对皮肤极其关键—主要是它们的抗氧化功能-黑葡萄和蓝莓富含这两种维他命元素。杏、桔子、青椒、萝卜、草莓和甘蓝都含有大量的类胡萝卜素色素，这种色素可在你体内转化为维生素A。”

营养学作家迈克尔·万·斯达特说：“胡萝卜汁富含β 胡萝卜素。一天喝一杯，新鲜的效果更好，这会对皮肤有着神奇的效果，因为它是绝佳的抗氧化剂。”

自然疗法营养学家夏洛特·弗兰兹建议，摄入足量的脂肪酸可有效解决皮肤干燥和痤疮等问题。鱼油中的omega 3（欧米茄）元素所具有的消炎作用对湿疹和牛皮癣有显著疗效。

月见草油富含gamma(伽马)亚油酸，它可以改善你的肌肤、发质和指甲。

皮肤最重要的B族维生素是生物素，香蕉、鸡蛋和大米中都富含这种生物素。缺锌也是导致牛皮癣和痤疮的一个因素。芝麻、葵花子和南瓜子都含有丰富的锌。