Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Father absence linked to earlier puberty among certain girls

17.09.2010
Girls in homes without a biological father are more likely to hit puberty at an earlier age, according to a new study led by researchers at the University of California, Berkeley's School of Public Health.

The findings, to be published Sept. 17 in the Journal of Adolescent Health, found that the absence of a biologically related father in the home predicted earlier breast and pubic hair development, but only for girls in higher income households. The findings held even after the girls' weight was taken into account.

"The age at which girls are reaching puberty has been trending downward in recent decades, but much of the attention has focused on increased body weight as the primary culprit," said study lead author Julianna Deardorff, UC Berkeley assistant professor of maternal and child health. "While overweight and obesity alter the timing of girls' puberty, those factors don't explain all of the variance in pubertal timing. The results from our study suggest that familial and contextual factors – independent of body mass index – have an important effect on girls' pubertal timing."

The findings came from the Cohort study of Young Girls' Nutrition, Environment and Transitions (CYGNET), an epidemiologic project headed by Lawrence Kushi, associate director of etiology and prevention research at the Kaiser Permanente Northern California Division of Research. The project is part of the UC San Francisco Bay Area Breast Cancer and the Environment Research Center (BCERC), one of four centers funded by the National Cancer Institute and the National Institute of Environmental Health Sciences. Early puberty has been linked to greater risk for breast and other reproductive cancers later in life, among other health impacts.

"Although the main focus of the CYGNET Study is on environmental exposures, we are also keenly interested in the social and behavioral contexts in which maturation occurs," said Kushi. "These findings demonstrate that such factors may play important roles in the onset of puberty in girls."

The link between father absence and earlier puberty in girls has been found in previous research, but most of those studies relied upon recall of the girls' first periods, and few examined the contributions of body mass index, ethnicity and income.

In this new study, researchers recruited 444 girls ages 6-8 through Kaiser Permanente Northern California, and have been following them annually. Their analysis was based on the first two years of follow-up. They considered signs of puberty that occur before the start of menarche. In interviews with the girls' caregivers, the researchers asked about the residents in the girls' homes and their relationships to the children.

Among the girls studied, 80 reported biological father absence at the time of recruitment. Contrary to what the researchers expected, the absence of a biologically related father was linked to earlier breast development for girls in higher income families – those having annual household incomes of $50,000 or more. Father absence predicted earlier onset of pubic hair development only in higher income African Americans families.

The mechanisms behind these findings are not entirely clear, the study authors said. Evolutionary biologists have theorized that the absence of a biological father may signal an unstable family environment, leading girls to enter puberty earlier.

Another theory that has been posited is that girls without a biological father in the home are exposed more to unrelated adult males – specifically, the pheromones of these males – that lead to earlier onset of puberty. However, in this study, the presence of other adult males, including stepfathers, in the home did not alter the findings.

It is also unclear why father absence predicted early puberty only in higher income families, particularly for African American girls.

"It's possible that in lower income families, it is more normative to rely upon a strong network of alternative caregivers," said Deardorff. "A more controversial hypothesis is that higher income families without fathers are more likely to have a single mother who works long hours and is not as available for caregiving. Recent studies have suggested that weak maternal bonding is a risk factor for early puberty."

Another possibility is that higher income girls in father-absent homes may be exposed to more artificial light – which has been shown to accelerate puberty in animal studies – through television, computers and other forms of technology, according to the study authors. The researchers also suggested that higher income African American girls may be more exposed to certain beauty products, such as hair straighteners, which have estrogenic properties that could influence pubertal timing.

The study adds to the debate of why girls in the United States are entering puberty at an increasingly early age. Last month, a study of 1,200 girls led by BCERC researchers at Cincinnati Children's Hospital Medical Center found that about 15 percent of the girls showed the beginnings of breast development at age 7, an increase from similar studies conducted in the 1990s.

"The hunt for an explanation to this trend is significant since girls who enter puberty earlier than their peers are not only at greater risk for reproductive cancers, they are also more likely to develop asthma and engage in higher risk sexual behaviors and substance abuse, so these studies have broader relevance to women's health," said Bay Area BCERC's principal investigator Dr. Robert Hiatt, UCSF professor and co-chair of epidemiology and biostatistics, and director of population science at the campus's Helen Diller Family Comprehensive Cancer Center.

"In some ways, our study raises more questions than it answers," said Deardorff. "It's definitely harder for people to wrap their minds around this than around the influence of body weight. But these findings get us away from assuming that there is a simple, clear path to the earlier onset of puberty."

Other co-authors of the study are Paul Ekwaru, UC Berkeley Ph.D. student in epidemiology; Bruce Ellis, professor at the University of Arizona; and pediatrician Dr. Louise Greenspan, project manager Anousheh Mirabedi, and research assistant Evelyn Landaverde at Kaiser Permanente Northern California's Division of Research.

Sarah Yang | EurekAlert!
Further information:
http://www.berkeley.edu

More articles from Studies and Analyses:

nachricht Real-time feedback helps save energy and water
08.02.2017 | Otto-Friedrich-Universität Bamberg

nachricht The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Switched-on DNA

20.02.2017 | Materials Sciences

Second cause of hidden hearing loss identified

20.02.2017 | Health and Medicine

Prospect for more effective treatment of nerve pain

20.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>