More girls are having their first period at younger ages and taking longer to reach menstrual cycle regularity, as highlighted in a May study published in JAMA Network Open. Early and irregular periods have long been linked to poor health effects.

Early periods may be influenced by socioeconomic backgrounds, high body mass index during childhood, low activity levels and electronic screen time.

Having prolonged irregular cycles results in extended exposure to an imbalance between estrogen and progesterone, which could increase the risk of endometrial cancers and fertility problems.

Another possible factor behind early puberty in girls is exposure to estrogenic compounds. Tips are included to help lower your child’s estrogen load.

Puberty is an important period of development that signifies the transition between childhood and adulthood, marked by significant physical, emotional, psychological and social changes.

For girls, one of the most notable milestones of puberty is the onset of menstruation (menarche), which ultimately leads to reproductive maturity. Traditionally, the average age for menarche is between the ages of 12 and 15.

However, a concerning trend has emerged over the past few decades in the US and globally – more girls are having their first period at significantly younger ages.

This shift toward early menarche is not just a minor deviation from the norm. It could also signal health issues later in life, as highlighted in a May study published in JAMA Network Open. The May JAMA Network Open study is among many that underscore the rising incidence and implications of early menarche, defined as menstruation before age 11.

The researchers looked at data from 71,341 female participants in the US, born between 1950 and 2005, who completed surveys for the Apple Women’s Health Study, a long-term research initiative aimed to examine menstrual cycles using data collected from the Apple Health mobile app.

Aside from analysing the age at which participants experienced menarche, the researchers also considered how long it took for their menstrual cycles to become regular, tracking these trends across different demographic groups.

Their findings revealed that the average age at menarche decreased from 12.5 years (for those born between 1950 and 1969) to 11.9 years (for those born between 2000 and 2005). Alarmingly, the percentage of girls experiencing early menarche increased from 8.6 per cent to 15.5 per cent, and very early menarche (before age 9) from 0.6 per cent to 1.4 per cent.

The percentage of girls reaching menstrual cycle regularity within two years also dropped from 76.3 per cent to 56.0 per cent, while those with irregular cycles increased from 3.4 per cent to 18.9 per cent.

The researchers noted:

“Despite a relatively small magnitude of change in mean age, our study is among the first to show that the percentages of early and very early menarche have also increased by almost twofold across birth years from 1950 to 2005, raising concerns that more individuals may be vulnerable to adverse health outcomes related to early menarche.”

They also emphasised that these trends are more pronounced among females from racial and ethnic minorities, including non-Hispanic Black, Asian and multiracial individuals, as well as those from lower socioeconomic backgrounds.

Moreover, body mass index, or BMI, accounts for about 46 per cent of the trend towards earlier menarche, indicating that the rising rates of childhood obesity play a role, but is not the sole factor.

“This is important because early menarche and irregular periods can signal physical and psychosocial problems later in life, and these trends may contribute to the increase in adverse health outcomes and disparities in the US,” Dr Zifan Wang, the lead study author and a postdoctoral research fellow at Harvard University’s T.H. Chan School of Public Health, told CNN.

In a case-control study published in Scientific Reports, researchers investigated the collective impact of electronic screen time, moderate-to-vigorous physical activity and overweight/obesity on early pubertal development in girls.

They examined data from 177 girls newly diagnosed with early puberty and 354 girls with normal development in China. Their analysis revealed a significant association between having any two risk factors and the likelihood of early puberty. High screen time coupled with low activity correlated with a 13-fold increase in risk.

High screen time combined with being overweight or obese led to a 6.5-fold higher risk. Meanwhile, low activity combined with overweight or obesity resulted in a sixfold increase in risk.

Girls who exhibit all three risk factors have a whopping 26-fold higher risk of early puberty. Drawing from these findings, the authors highlighted the importance of maintaining a healthy lifestyle for adolescents:

“We recommend girls do not spend their leisure time watching TV or on other electronic screens, avoid a sedentary lifestyle, which is characterised by both low MVPA [moderate to vigorous physical activity] and high EST [electronic screen time], but instead spend more time exercising for reasons related to obesity and also potential early puberty, even in girls of normal weight.”

Dr Eve Feinberg, associate professor of obstetrics and gynaecology at Northwestern University’s Feinberg School of Medicine in Chicago, likened menstruation to a vital sign.

“You want to make sure that the body is regulated. And when cycles are not regular, it’s generally a sign that something else may be going on,” she told CNN.

Early and irregular periods have long been linked to poor health effects. According to the featured JAMA Network Open study:

“Early menarche is associated with increased risk of adverse health outcomes, such as cardiovascular diseases, cancers, spontaneous abortion and premature death. …

“The maturation of the reproductive axis, measured as the time from menarche to established cycle regularity, is another important but understudied hallmark of early-life menstrual health. …

“Full maturation of the reproductive axis leads to more regular menstrual function. Longer time to regularity has been associated with lower fecundability, longer menstrual cycles and increased risk of metabolic conditions and all-cause mortality.”

Research has also associated early menarche with obesity, diabetes and psychosocial problems like delinquency and risky social behaviour. Moreover, Feinberg noted that having prolonged irregular cycles results in extended exposure to an imbalance between estrogen and progesterone, which could increase the risk of endometrial cancers and fertility problems.

“Estrogen signals growth, whereas progesterone signals for that growth to stop. To prevent conditions such as uterine cancer, you need to have the signals to both start and stop growth,” she explained.

I agree with this perspective and have long warned about the dangers of excessive estrogen. In my mind, estrogen is one of the two primary reasons for most cancers, the other one being excessive consumption of linoleic acid.

In the CNN article, Feinberg suggested using birth control pills to control menstrual cycles. “Sometimes even using birth control pills at an earlier age to help give earlier exposure to progesterone … may give a little bit more cycle control and may possibly be protective,” she said.

I respectfully disagree with this recommendation because even though birth control pills are meant to mimic the effects of progesterone in the body, they can also further increase estrogen levels, which could potentially do more harm than good.

Typically, birth control pills contain synthetic versions of estrogen and progesterone (progestin) or progestin alone. However, progestin does not have the same physiological effects as endogenous progesterone, especially its anti-estrogenic effects.

In fact, progestins tend to lower and can completely shut down endogenous progesterone production, leaving estrogen unopposed.

Many progestins found in birth control pills, such as norethynodrel and norethindrone, can bind to and activate the estrogen receptor and are converted into oestrogens. Endogenous progesterone does not do this. This fundamental difference underscores why birth control pills may not be the ideal solution for regulating menstrual cycles.

To learn more about why I don’t recommend using birth control pills, read my article “The Disturbing Truth About Oral Contraceptives.”

• The Defender report