Men who married at the age of 25 or older had better bone health, say University of California, Los Angeles researchers.
"This is the first time that marriage has been linked to bone health," said senior author Carolyn Crandall, professor of medicine at UCLA.
"There is very little known about the influence of social factors - other than socio-economic factors - on bone health," Crandall added.
Among men who first married prior to turning 25, the researchers found a significant reduction in spine bone strength for each year they were married before that age.
Also, men in stable marriages or marriage-like relationships who had never previously divorced or separated had greater bone strength than men whose previous marriages had fractured, the researchers said.
And those in stable relationships also had stronger bones than men who never married, said the study published in the journal Osteoporosis International.
The researchers used data from the Midlife in the United States (MIDUS) study, which recruited participants between the ages 25 and 75 in 1995-96.
Participants from that study were re-interviewed in 2004-05 (MIDUS II).
Specifically, the authors used hip and spine bone-density measurements and other data to examine the relationship between bone health and marriage in 294 men and 338 women.
They also took into consideration other factors that influence bone health, such as medications, health behaviours and menopause.
"The associations between marriage and bone health were evident in the spine but not the hip, possibly due to differences in bone composition," Crandall said.
"Very early marriage was detrimental in men, likely because of the stresses of having to provide for a family," said study co-author Arun Karlamangla, a professor of medicine in the geriatrics division at the Geffen School.