This blog was originally published by Alysse ElHage on IFStudies.org, and has been republished here with permission from the author.
Having spent the majority of my childhood separated from my biological father, I can attest to the painful and far-reaching effects of father absence. Thankfully, as a wife and mother, I have experienced the unique power of father presence in my children's lives through my husband, and I can say with certainty that a biological father is more than just an extra paycheck or second set of hands in the home—he provides a central and irreplaceable role in the family.
Research tells us that father loss is linked to a broad range of negative outcomes for children, including lower rates of high school and college graduation, a higher risk of delinquency, early sexual activity, teen pregnancy, and poor mental, physical, and emotional health. Yet despite the emerging science of fatherhood, in many ways, we are only beginning to understand the significance of the biological father connection to child well-being.
New research indicates that the repercussions of losing a biological father—whether to death, divorce, or incarceration—go even deeper, affecting children at the cellular level. Colter Mitchell, Sara McLanahan, Lisa Schneper, Irv Garfinkel, Jeanne Brooks-Gunn, and Daniel Notterman authored the study, “Father Loss and Child Telomere Length,” which was published this month in the journal, Pediatrics.
Recently, I had the opportunity to interview the study's corresponding author, Daniel Notterman, a pediatrician and molecular biologist who teaches at Princeton University, about the findings. Following is an edited version of the interview.
Alysse ElHage: Your sample involved nine-year-old children from the Fragile Families and Child Well-Being Study. Tell us briefly about this study, and why you chose to focus on this sample of children?
Daniel Notterman: The Fragile Families & Child Wellbeing Study is following a cohort of nearly 5,000 children born in large U.S. cities between 1998 and 2000 (roughly three-quarters of whom were born to unmarried parents). We refer to unmarried parents and their children as “fragile families” to underscore that they are families and that they are at greater risk of breaking up and living in poverty than more traditional families. The core study was originally designed to primarily address four questions of great interest to researchers and policymakers: (1) What are the conditions and capabilities of unmarried parents, especially fathers?; (2) What is the nature of the relationships between unmarried parents?; (3) How do children born into these families fare?; and (4) How do policies and environmental conditions affect families and children? In 2007, we collected DNA from the children (then age 9) and their mothers; this collection was repeated when the children were age 15. The DNA was used for telomere and other studies.
Alysse ElHage: Why did you focus on telomere length in children (and, more generally, explain why telomere length matters to long-term health)?
Daniel Notterman: Telomere length (TL) has been shown in many studies to be associated with chronic stress of diverse origins in both children and adults. We reasoned that separation or loss of a father would be a significantly stressful event in the life of a young child. If that were the case, we hypothesized that father loss would be associated with telomere attrition, and that turned out to be the case. We know that chronic stress is also associated with long-term adverse effects on health, including cardiovascular and behavioral health. Whether accelerated telomere attrition is just a biomarker of these subsequent health effects, or actually plays a causal role in producing these effects is not known at present, but it is the subject of intense laboratory and clinical study. In either case, by examining telomere length, we get an early window (by age 9 years in our study) into adverse health effects that may not be realized for many years.
Alysse ElHage: The study found that father loss is associated with a 14% reduction in telomere length. It also found key differences in the types of father loss associated with telomere shortening—with a father’s death having the longest association at 16%, followed by incarceration at 10%, and divorce/separation at 6%. What else did you find in terms of the impact of father loss on some children?
Daniel Notterman: Father loss was conceptualized as being of one of three types: separation of the biologic father from the child’s mother, often due to the dissolution of their relationship; incarceration of the child’s father; and death of the father before the child was 9 years of age. In addition to the associations noted in the question, we also found evidence of genetic moderation. Due to the presence of specific gene variants (called, “alleles”) in a gene called “SERT,” which is known to affect how the brain processes serotonin, a key neurotransmitter, some children seem to be more sensitive to environmental stimuli such as loss of a parent. In our study, children bearing a sensitizing allele, or variant, or SERT are much more susceptible to telomere shortening. Thus, the magnitude of telomere shortening is affected not only by the loss of a father but also by the genetic endowment received from the parents.
Alysse ElHage: Why does the loss of a father to death appear to matter more in terms of the impact on telomere length in children?
Daniel Notterman: We conjecture that loss of a father due to death is a more potent stress because it completely ends the relationship between father and child. With separation and incarceration, it is still possible for there to be contact between father and child. Fathers who are separated from the family often maintain contact with a biological child, and incarceration may be limited in time.
Alysse ElHage: The effects of father loss on telomere length were 40% greater for boys than girls. Why is that?
Daniel Notterman: We conjecture that the effect of father loss is somewhat greater for sons than daughters. Fathers may provide specific role-modeling to sons. However, our study was not specifically designed to answer this question.
Alysse ElHage: The study also found that the impact of father loss on telomere shortening was mediated by income. Explain that finding for us if you will?
Daniel Notterman: We found that father loss due to the dissolution of the relationship with the child’s mother affects telomere length mainly by reducing family income. We conjecture that this is due to the stress engendered by material hardship (worsening poverty). Father loss due to incarceration or death seems to be a much more potent stress, such that the additional contribution of income loss is relatively small.
Alysse ElHage: Previous research indicates that the impact of father loss on children is usually less negative if a father dies than if he is absent due to divorce/separation. But in your study, you show that the loss of a father due to death had the greatest impact on telomere length in children. Why the difference?
Daniel Notterman: We speculate that loss of a father due to death was associated with greater telomere length reduction because the negative consequences of father’s death are underestimated in studies that rely exclusively on survey questions to measure health and disease, especially in children. If so, this points out the importance of biomarkers in evaluating or predicting health outcomes.
Alysse ElHage: What do you hope the study’s findings add to what we already know and are continuing to learn about the importance of fathers to children’s health?
Daniel Notterman: We think that our findings reinforce the growing understanding of a father’s importance in the life of his children. We do not think that our data support a conclusion that one type of relationship between a child’s parents is more favorable than another; rather, we conclude that a central role for the father is optimal for his child’s well-being. Furthermore, we think that this knowledge should inform public policy in providing support to families and children where the father, for one reason or another, is absent from his children.