Does Brain Size Shrink Over Time?

PHILADELPHIA (CBS) - Does a person's brain shrink as they age?

It is an interesting question. We could look at MRIs to find out but one of the problems with many studies that look at x-rays, MRIs, or diagnostic heart tests is that people who are getting the studies performed are already ill with certain medical conditions. In other words, they have abnormalities in the studies and the message becomes everyone in a certain age group has the abnormality which may or may not be true.

A report in the journal Neuropsychology makes that point. In this article, researchers discovered that the scientific belief that older brains are substantially smaller than younger brains may stem from studies that did not screen out people who had undetected, slowly declining brain disease.

According to the new study which looks at people who were healthy for nine years, healthy people without mental decline had similar sized brains as younger people. It was only those who had mental decline who had the smaller brains.

Reported By Dr. Brian McDonough, KYW Newsradio Medical Editor