There are many misconceptions and rumors about what does and does not cause the condition:

• Diet . One study concluded that chocolate , french fries , potato chips and sugar , among others, affect acne. A high GI ( glycemic index ) diet allowing sharp rises in blood sugar worsens acne. If the studies conclusions are verified then a low GI diet may help acne. A recent review of scientific literature cannot affirm either way. The consensus among health professionals is that acne sufferers should experiment with their diets, and refrain from consuming such fare if they find such food affects the severity of their acne. A recent study, based on a survey of 47,335 women, did find a positive epidemiological association between consumption of partially skimmed milk and acne. The researchers hypothesize that the association may be caused by hormones (such as bovine IGF-I ) present in cow milk; but this has not been definitively shown. Seafood , on the other hand, may contain relatively high levels of iodine , but probably not enough to cause an acne outbreak. Still, people who are prone to acne may want to avoid excessive consumption of foods high in iodine. It has also been suggested that there is a link between a diet high in refined sugars and acne. According to this hypothesis, the startling absence of acne in non-westernized societies could be explained by the low glycemic index of these cultures diets. Further research is necessary to establish whether a reduced consumption of high-glycemic foods (such as soft drinks, sweets, white bread) can significantly alleviate acne, though consumption of high-glycemic foods should in any case be kept to a minimum, for general health reasons. Avoidance of 'junk food' with its high fat and sugar content is also recommended .
• Deficient personal hygiene . Acne is not caused by dirt. This misconception probably comes from the fact that acne involves skin infections. In fact, the blockages that cause acne occur deep within the narrow follicle channel, where it is impossible to wash them away. These plugs are formed by the cells and sebum created there by the body. The bacteria involved are the same bacteria that are always present on the skin. Very little variation among individuals is due to hygiene. Anything beyond very gentle cleansing can actually worsen existing lesions and even encourage new ones by damaging or overdrying skin.
• Sex . Common myths state that masturbation causes acne and, conversely, that celibacy or sexual intercourse can cure it. There has been no scientific evidence suggesting that any of these are factual.

  Source wikipedia

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