Many different foods have been blamed for causing or aggravating acne. Shellfish, sugar, mushrooms, tomatoes, and who knows what other foods have at times been seen as causing acne. But the fact is that the foods you eat have no impact on your acne–except in the general sense that the good diet improves your overall health, and good health, including good skin health, will tend to mitigate the negative impact of acne.

However, there is one diet ingredient that has been shown to have a meaningful, direct and negative impact on acne. Dietary iodides are excreted through the sebum-producing sebaceous glands and may cause an acne flare-up, usually within 10 to 15 days of the start of consumption. Such iodides are not widely available. However, they are occasionally found in three sources. Two of them certain dietary supplements and some seaweeds-are rare and it is unlikely that you would be consuming large quantities of them, although it is not impossible if you have started on one of several rather exotic diets.

More probable is the third source of iodide: It is found in certain water supplies, especially in the Caribbean islands, where the drinking water is desalinized seawater. If your acne broke out a few days after you started your Caribbean vacation, it may be the result of iodide in the drinking water. Of course, if the acne starts about the time you are returning, it may be the result of the stress caused by the overloaded in basket you face on getting back to your office. If the acne disappears spontaneously within a few days, chances are it was the drinking water. If it doesn’t, stress may be the culprit. In either case, of course, the treatment program we have described can eliminate the problem.