Eating too much refined bread and cereal may be one of the causes of teenage acne, according to a team of US scientists reports this month's New Scientist​.

A team of researchers led by Loren Cordain, described by the report as 'an evolutionary biologist' at Colorado State University in Fort Collins, US, suggest that the highly processed breads and cereals, which have become a staple of the Western diet, lead to the excessive levels of male hormones which cause acne.

The researchers explain that refined grain products are easily digested and the resulting 'flood of sugars' makes the body produce large amounts of insulin and insulin-like growth factor (IGF-1), leading to the excessive production of male hormones, according to the report. IGF-1 also encourages skin cells called keratinocytes, a hallmark of acne, to multiply.

The team will publish its findings in the December issue of Archives of Dermatology​.

The report notes that almost all 18-year-olds in modern societies suffer from acne, but 'subsistence' societies such as the Kitava islanders in Papua New Guinea and the Ache of the Amazon rarely see symptoms of the condition. The US researchers believe this is because there are no refined sugars or grains in their diets.

The report explains that modern processing techniques disrupt the protein structures of grains used in refined foods. Digestion is made easier, but the pancreas responds to this by producing high amounts of insulin.

New Scientist​ adds that an Australian team at RMIT University in Melbourne is to test the theory by studying the effects of a low-carbohydrate diet on boys with acne.