Grannies give gift of longer life
Have you thanked your grandma today?
You might want to consider it. A recent study found that kids have more of their own children and grandkids live longer when a grandmother takes part in their daily lives.
Most animals die soon after their childbearing years are over. Women, however, often live for many years after they stop having kids.
To try to understand why, researchers from Finland looked at birth and death records of two communities from the 18th and 19th centuries, one in Finland and one in Canada. In these communities, 537 Finnish women and 3,290 Canadian women were grandmothers who had lived past age 50.
For every decade they lived beyond 50, the researchers found, the women ended up with an average of two extra grandkids. It didn't matter what the differences in health or living conditions were between the two communities or from family to family.
Grandchildren were also more likely to live into adulthood if their grandmothers were alive when they were born. If their grandmothers were younger than 60 at the time, that was even better. The study also found that people had children 2 to 3 years earlier if their own parents were still alive than did those whose mothers had died.
To explain these trends, the researchers propose that grandmothers have provided important assistance in raising their grandchildren for at least the past 200,000 years. As a result, they helped extend everyone's lifespan.
So, don't take your grandma for granted!
Bower, Bruce. 2004. Grannies give gift of longer lives. Science News 165(March 20):188-189. Available at http://www.sciencenews.org/articles/20040320/note13.asp .