Posted on 11/07/2002 2:06:14 PM PST by Pharmboy
WASHINGTON (Reuters) - Motherhood may make women smarter and may help prevent dementia in old age by bathing the brain in protective hormones, U.S. researchers reported on Thursday.
Tests on rats show that those who raise two or more litters of pups do significantly better in tests of memory and skills than rats who have no babies, and their brains show changes that suggest they may be protected against diseases such as Alzheimer's.
University of Richmond psychology professor Craig Kinsley believes his findings will translate into humans.
"Our research shows that the hormones of pregnancy are protecting the brain, including estrogen, which we know has many neuroprotective effects," Kinsley said.
"It's rat data but humans are mammals just like these animals are mammals," he added in a telephone interview. "They go through pregnancy and hormonal changes."
Kinsley said he hoped public health officials and researchers will look to see if having had children protects a woman from Alzheimer's and other forms of age-related brain decline.
"When people think about pregnancy, they think about what happens to infants and the mother from the neck down," said Kinsley, who presented his findings to the annual meeting of the Society of Neuroscience in Orlando, Florida.
HORMONES WASHING THE BRAIN
"They do not realize that hormones are washing on the brain. If you look at female animals who have never gone through pregnancy, they act differently toward young. But if she goes through pregnancy, she will sacrifice her life for her infant -- that is a tremendous change in her behavior that manifested in genetic alterations to the brain."
Kinsley's team tested rats that had never had a litter of pups, had raised one litter, or had raised two or more litters. The rats ranged in age up to two years -- the equivalent of 70 to 80 years in a human, Kinsley said.
The rats were given two tests involving finding food inside and outside a maze. They were retested several times over two years.
"Females who had two reproductive experiences were able to learn and remember the maze better than females with one or zero," Kinsley said. "Females with zero were not able to do the maze as well as females with one (pregnancy)."
The team later killed the rats and looked at their brains -- specifically at the hippocampus, the region of the brain associated with learning and memory. The rats that had several pregnancies had lower levels of a protein called amyloid precursor protein -- which, in humans, is associated with the development of Alzheimer's.
He needs to do more tests but believes the effect may be even stronger in human females, who invest much more time and effort in raising offspring. Humans also have the "grandmother effect" -- older women in most societies play a role in raising their grandchildren and thus the children benefit from having grandmothers who engage their faculties.
Kinsley said he became interested in his research after his wife had a baby during an especially stressful year when he started a new job and the family moved to a new house.
"Watching her and how her behavior became more efficient during this time got me thinking about the links between maternal behavior and maternal efficiency," he said. "Nature seems to provide the mother with a boost to enable her to care, long term, for the most important and costly genetic and metabolic investment she will ever make -- her offspring."
They shoulda saved this for Mother's Day--it would have gotten picked up by more of the media.
That's funny...I just had child #2 and feel like a little bit of dimentia has already set in. I'm glad I'll be spared any more of it in my old age.
More "scientists" studying rats, with your tax dollars, and then making completely unscientific extrapolations. Anyone who studied coyotes and then made claims about timberwolf behavior would be laughed out of the symposium. But these pseudoscientists study rats, make millions, and then make claims about human behavior. Sheeesh.
And, there have been earlier studies that showed a benefit of HRT in Alzheimer's; this is not the first study to show the association. But, we do need a prospective, controlled study for the proof (with bigger numbers also).
So THAT's why married women tend to vote Republican.
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