Girls are becoming women at younger ages, and sugar-sweetened beverages might be playing a role.
A new study of US girls found that those who drank more sugar-laced drinks started their periods earlier than girls who limited consumption. The authors of this study said that early menarche — the age at which a girl starts her menstrual periods — could be related to hormonal effects from the extra sugar.
"We live in an age where everyone studies the effects of each type of food separately and tries to prove or disprove its effect in disease. But our diet, lifestyle and environment has substantially increased the number of toxins to which our body is exposed. This has drastic negative effects. We need to address our diets, lifestyle and environment to minimize the toxins we are bringing into our bodies," said Anand Bhatt, MD, a board-certified pediatrician on the medical staff at Baylor Medical Center at Irving.
"The habits of kids eating sweet cereals, drinking juice all the time or drinking sweetened beverages are not so harmless and have far reaching implications. They affect long-term health by disrupting complex physiologic systems in our body," said Dr. Bhatt, who was not involved in this study.
The authors of this new study, led by Karin B. Michels, ScD, PhD, an associate professor at Harvard Medical School in Boston, noted that reducing sugar intake may have a positive health effect on these girls, such as decreasing their risk of obesity. Past research has looked at the relationship between nutrition and menarche, but this was the first study to look specifically at sugar-sweetened beverages (SSBs).
"Our study adds to increasing concern about the wide-spread consumption of sugar-sweetened drinks among children and adolescents in the USA and elsewhere," Dr. Michels said in a press release. "The main concern is about childhood obesity, but our study suggests that age of first menstruation (menarche) occurred earlier, independently of body mass index, among girls with the highest consumption of drinks sweetened with added sugar. Our findings provide further support for public health efforts to reduce the consumption of sugary drinks."
According to Dr. Bhatt, this study highlights the need for families and doctors to understand that eating excessive amounts of these unhealthy foods has metabolic and physiologic sides effects.
"In a fast-paced society where frozen foods, canned foods, fast foods and processed foods have become the norm, we have to step back and examine that the preservatives, the sugar content and the salt content all have adverse consequences. And these consequences can extend not only to obesity, high blood pressure, diabetes and high cholesterol, they can also extend to precocious puberty, early menarche, menstrual irregularity, polycystic ovarian disease and fertility problems," Dr. Bhatt said.
"The basic sciences are fast detecting that big diseases have their source in the [gastrointestinal] tract and early on cause some biochemical disruption. The nutrition of our children is important for a parent not just for good habits but more fundamentally for the long-term health of that child," he said.
For this study, Dr. Michels and team followed more than 5,500 girls from 1996 to 2001. These girls were part of the larger Growing Up Today study. They were ages 9 to 14 at the start of the study.
Girls who drank more than 1.5 servings of sugar-sweetened sodas or fruit juices started their periods almost three months earlier than those who drank two or fewer of these drinks a week. Other factors like weight, total food intake and physical activity did not appear to affect these findings.
Dr. Michels and team assessed the effects of drinking one can, glass or bottle of SSBs like sodas, fruit drinks, lemonade, punch and iced tea. They also included diet sodas and plain fruit juice.
SSBs meant an earlier menarche, but sugar-sweetened iced tea did not appear to have the same effect. Diet sodas and fruit juice did not seem to affect the time at which girls started their period, Dr. Michels and team found.
The effect of SSBs was modest. Girls who drank more than 1.5 servings of an SSB each day started their periods at about 12.8 years of age. Girls who drank fewer than two servings a week started their periods at about 13 years of age.
An earlier menarche may increase the risk of breast cancer later in life, Dr. Michels and team said.
Drinks high in sugar can increase insulin, the hormone that regulates blood sugar. High insulin in the bloodstream can also cause an increase in sex hormones, which might affect the age of menarche, Dr. Michel and colleagues noted.
For parents, this study may add to the reasons to limit servings of SSBs in preteens and teens.
This study was published online Jan. 27 in the journal Human Reproduction.
The authors disclosed no funding sources or conflicts of interest.