The absence of a father has adverse physical and behavioural consequences for a growing child, especially boys, reveals a recent study.
Researchers from Princeton University reported that the loss of a father has a significant adverse effect on telomeres, the protective nucleoprotein end caps of chromosomes.
At nine years of age, children who had lost their fathers had significantly shorter telomeres - 14 percent shorter on average - than children who had not. Death had the largest association and the effects were greater for boys than girls.
Telomeres are thought to reflect cell aging and overall health; their role is to help maintain the DNA ends of chromosomes following cell division.
Each time a cell divides, its telomeres shorten; once telomeres are too short, cell replication stops.
Previous research has suggested that shortened telomeres are associated with a wide range of diseases in adults, including cardiovascular disease and cancer.
Researchers analysed 5,000 children born in large U.S. cities at the turn of the 21st century.
The study has gathered information on the children's physical and mental health, cognitive function, social-emotional skills, schooling and living conditions, as well as the makeup, stability and financial resources of their families.
They then examined whether the type of father loss - incarceration, death, separation or divorce - and the timing of the loss in early childhood or middle childhood mattered.
They determined that father loss is clearly associated with cellular function as estimated by telomere length: any father loss between birth and 9 years of age leads to a reduction in telomere length and the effect is greatest for children whose fathers die, about 16 percent shorter.
Corresponding author Daniel Notterman said that if father is being removed from the life of a child then that is plausibly associated with an increase in stress, for both economic and emotional reasons.
This association is especially strong for boys who lost or were separated from their fathers before the age of five.
A child's genotype may lessen the association between a child's social environment and telomere length, and serve as a protective factor.
The research is published in the journal Pediatrics.