Girls’ menstrual periods starting earlier in life

Health in a Heartbeat

Menstruation has never been an easy topic. And why would it be? In the Middle Ages, it was commonly believed that menstrual blood could kill crops and dull mirrors.

Some even held that a menstruating person could shoot “poisonous vapors” from their eyes. Hey, no one said that era was big for science.

A new study from researchers at Harvard, the National Institute of Environmental Health Sciences and Apple has found that in the decades since 1950, American girls have been starting their menstrual cycles at a younger age.

The study relied on the Apple Women’s Health Study’s dataset of more than 71,000 participants, who self-reported their health information.

Of those born from 1950 to 1969, the average age of menarche [men-aahr-kee] was 12 years and six months. For those born between 2000 and 2005, the average age was 11 years, nine months.

Another finding: It’s taking longer for menstrual cycles to become regular.

The researchers found all of the trends most pronounced for Black, Hispanic, Asian or mixed-race women, or those who rated themselves as having a lower socioeconomic status.

The researchers don’t know why girls are starting to menstruate earlier, but they have some theories. Childhood obesity, epidemic in the U.S., might be a factor, as could diet, stress, environmental chemicals and air pollution.

They do know it needs to be studied — and talked about — more. Earlier menstruation is associated with a higher risk for health problems like heart disease and cancer, so understanding why is a life-or-death matter.

The good news is that we can talk about the topic today, free of the superstitions of the past.