ST. PAUL, MN – Children in large families may have a greater risk of developing Alzheimer's disease than children from smaller families, according to a study in the January 25 issue of Neurology, the scientific journal of the American Academy of Neurology.
The study found that the risk of developing Alzheimer's increases by eight percent for each additional sibling in the family. Those growing up with five or more siblings have a 39-percent greater risk of developing the disease than those with fewer than five siblings.
The study examined 770 people age 60 and older who were members of a large health maintenance organization in Seattle, Wash. Of the participants, 393 had Alzheimer's disease and 377 had no signs of dementia.
Researchers looked at whether any environmental factors in the participants' childhood were related to developing Alzheimer's. "The early-life environment and its effect on the growth and maturation of children is linked to many adult diseases, such as heart disease, stroke and diabetes," said study author Victoria Moceri, PhD, of the University of Washington. "We wanted to test whether Alzheimer's may also have a link to the early-life environment."
The areas of the brain that show the earliest signs of Alzheimer's are the same areas of the brain that take the longest time to mature during childhood and adolescence, Moceri said. "A poor quality childhood environment could prevent the brain from reaching a complete level of maturation," she said. "The effects of impaired development could produce a brain that is normal, but functions less efficiently."
Moceri said the negative effects of this less efficient brain would likely be marginal until they were aggravated by the aging process.
"Families with five or more children were more likely to be from the lower socioeconomic levels, and therefore more likely to have poor growth rates," Moceri said. Researchers also found th
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American Academy of Neurology
24-Jan-2000