Childhood obesity can play a major role in hindering the natural onset of puberty and thus pave the way for a rise in infertility rates and reproductive problems, scientists warn.
An analysis published in Frontiers in Endocrinology examined the hidden risks associated with childhood obesity and found a visible link with a reduced ability to reproduce, or infertility, a common problem haunting US adults, recently.
"The issue of so many humans being obese is very recent in evolutionary terms, and since nutritional status is important to reproduction, metabolic syndromes caused by obesity may profoundly affect reproductive capacity," said study author, Patrick Chappell, an assistant professor of veterinary medicine at Oregon State University, in a statement.
"Either extreme of the spectrum, anorexia or obesity, can be associated with reproduction problems."
The major sign of puberty for girls is menarche or the first menstrual bleeding. Menarche normally starts after a girl turns 11 years old. But, recent studies show that girls are entering puberty at an early age compared to earlier generations.
Scientists found the early onset of puberty and being overweight negatively affecting kisspeptin, a neurohormone essential for reproduction. Endocrine signals from fat that help in communication with the brain disturb the natural discharge of the hormone.
Another major finding was the disturbance of circadian clocks or sleep-wake cycles affecting hormones like cortisol, testosterone and insulin, thus affecting puberty timing and reproduction.
"Any disruption of circadian clocks throughout the body can cause a number of problems, and major changes in diet and metabolism can affect these cellular clocks," Chappell said.
"Disruption of the clock through diet can even feed into a further disruption of normal metabolism, making the damage worse, as well as affecting sleep and reproduction."
The findings come at a time when childhood obesity has more than tripled in the United States over the past 30 years. A Centers for Disease Control and Prevention report shows a shocking increase in the number of obese children aged six to 11, from 7 percent in 1980 to 20 percent in 2008.
A study published in Pediatrics in 2011 found about 15 percent of US girls hitting puberty by age seven. Researchers found that stress of family breakdown and rise of obesity plays a major role in the onset of early puberty.
An early menarche brings in many health problems for women. It increases the risk of developing cardiovascular disease, metabolic dysfunction, cancer and depression in later years.
