The June 2005 issue of Biology of Reproduction includes a special paper by a team of Spanish scientists indicating that delayed motherhood in mice results in shorter life expectancy and reduced body weight in their offspring.
Negative effects of late maternal age in women, such as abnormal numbers of chromosomes in their children, are well known. However, other potential negative effects on offspring from delayed motherhood have been only anecdotal.
In what the editors of Biology of Reproduction feel will be a controversial topic of discussion, a team of reproductive biologists headed by Juan Tarín at the Department of Pediatrics, University of Valencia, Spain, presents data in the June issue of the journal that delayed motherhood in mice results in decreased life expectancy and reduced body weight of their offspring.
Several other aspects of reproductive fitness of offspring were assessed, but none showed significant deleterious effects.
This report identifying effects of delayed motherhood on life expectancy and body weight of offspring will surely stimulate inquiries into mechanisms resulting in these disturbing consequences, as well as epidemiological studies in humans, according to the editors of Biology of Reproduction.
The abstract for this report does not provide much detail on the size of the effect.
Do humans born to older mothers suffer decreased life expectancy? If so, by how much? We will have to wait for epidemiological research to answer this question. But epidemiological data is hard to interpret. Women who have babies later in life are, on average, also more able to have babies later in life than women who do not do so. Well, does that ability come as a result of genetic variations that influence life expectancy? We'd need data in women who have multiple children at ages that are far apart from each other in order to compare life expectancy of babies born to the same mother years apart.
|Share |||Randall Parker, 2005 May 23 02:59 PM Aging Studies|