Chemicals in high-street cosmetics may cause early puberty in girls

High street perfumes, hand creams, make-up and body lotions containing chemicals such as diethyl phthalate and methyl paraben could cause girls to go through puberty early, a study by researchers at the University of California has suggested.

The chemicals commonly used in cosmetics, and which have only be banned by the EU in significant concentrations this year, could cause girls to start their puberty months earlier than the average, the report published in the journal Human Reproduction found.

Almost 200 girls were tracked from birth to adolescence, checking for signs of puberty every nine months between the ages of nine to 13.

The chemicals the youngsters were exposed to in the womb and while growing up are believed to have affected the female sex hormone oestrogen, triggering adolescence early. 

The study found that children started puberty earlier if their mothers were exposed to triclosan, which is found in some antibacterial hand washes and toothpaste, with the mothers’ urine measured between 14 and 27 weeks of pregnancy. 

The daughters of women with the highest levels went on to start their periods, on average, four months earlier. 

Meanwhile, the daughters of women with the highest levels of diethyl phthalates developed body hair around six months earlier than usual, compared to those exposed to the lowest level.

Links were also found between propyl paraben, which is used in perfumes, and chlorine-containing chemicals, which appear in cosmetics in the US but are only for industrial use in Britain. 

Lead author Dr Kim Harley said chemicals in personal care products “interfere with natural hormones in our bodies, such as oestrogen”. 

She said: “We know the age at which puberty starts in girls has been getting earlier in the last few decades and one theory is that chemicals in the environment might be playing a role. 

“This is an important issue to address as earlier puberty in girls increases their risk of mental health problems and risk-taking behaviour as teenagers, as well as breast and ovarian cancer over the longer term.”

338 children of both sexes were followed from birth to adolescence but it was only girls who entered puberty when exposed to certain chemicals – not boys.

Meanwhile, another study has compared the anti-ageing properties of retinol with an ingredient found in an Indian plant, leading to “promising” findings.