Iodine in milk linked to teenage acne
says a US dermatologist, though hard evidence of a link remains
scarce and disputed.
Harvey Arbesman, a dermatologist at the University of Buffalo in New York, made the link in a letter published in the Journal of the American Academy of Dermatology.
He cited a study published in the Journal last February that suggested hormones and bioactive material in milk may increase teenagers' risk of acne.
Arbesman said another cause could be the iodine: "It is well established that iodine can exacerbate acne. [And] various studies have shown significant levels of iodine in milk in different countries, including the US, Britain, Denmark, Norway and Italy.
"Thus, the observed association of dairy products with acne may be secondary to the iodine content of the dairy products ingested."
Arbesman said that giving cows iodine-fortified feed to prevent infection, and using iodine solutions to clean cows' udders and milking equipment, meant there was a lot of iodine in dairy products.
"For that reason, I've advised my acne patients for years to decrease their dairy intake," he said, calling for more studies on the issue.
The letter was greeted with caution elsewhere in the world of dermatology.
"Its an interesting idea with some theoretical basis that could be looked into, but pure conjecture at present," said Hywel Williams, professor of dermato-epidemiology at the UK's University of Nottingham, to www.DairyReporter.com.
Susan Bershad, of the US Mt Sinai School of Medicine, said the February study linking dairy intake and acne was dubious. She said significant other factors such as heredity, nationality and socio-economic status had not been accounted for.
Some countries, despite Arbesman's comments, are also still trying to deal with the bigger problem of iodine deficiency in peoples' diets.
Ironically, a recent newsletter from the University of Otago, in New Zealand, said that less iodine in milk was a big factor in the country's iodine deficiency problem.
A lack of iodine in the soil there has meant a lack in the diet, which can cause goitre - where the thyroid gland in a person's neck grows significantly bigger, causing physical discomfort and distress.
"For the last 40 years, most of our iodine has come from milk, other dairy products made from milk, and from iodised salt. However, the dairy industry has changed its work practices, so that the amount of iodine in milk is lower," said Otago.
It published a study in 2003 revealing that nearly 30 per cent of New Zealand children were not getting enough iodine in their diets.
The University also confirmed to www.DairyReporter.com that it was conducting research into pregnant women's iodine intake. Some evidence suggests iodine deficiency may damage brain development in unborn babies.
A report in the New Zealand Herald last week said the country's Health Ministry was thinking of advising pregnant women to take iodine supplements.
Dr Sheila Skeaff, lead researcher on Otago's pregnant women study, said the New Zealand government would make changes to iodine fortification in foodstuffs next year.
She said pregnant women needed 220 micrograms per day, but that estimated that adult New Zealanders were only getting between 75 and 100 micrograms.
