Do men's brains thrink faster than women's brains?

Those who study such things say that as we age, a man's brain shrinks more rapidly than a woman's.
February 14, 1998
BBC - Sci/Tech

New research suggests that the male brain shrinks faster with age than the female brain.

It is not clear exactly how the different shrinking rates affect the way men or women think. Tests have shown men and women perform similarly despite their difference in brain sizes.

But it is thought that this may help to explain why men are more prone to age related problems such as memory loss.

Brain drain

Human brains reach their full size in adolescence and begin shrinking after age 20.

As the brain gets smaller, the amount of fluid between the brain and skull increases.

The American study published in Archives of Neurology found that between the ages of 65 and 95, men had a 30% increase in fluid, but women only had a 1% increase.

But Dr C. Edward Coffey, a neuropsychiatrist at Henry Ford Behavioral Services in Michigan who has been studying brain ageing for five years, said there is no evidence that brain size alone determines a person's ability to function.

Although the brain shrinks at about 10% every 10 years, doctors do not know why.

It could be linked to a build-up of toxins in the brain, or cells could be programmed to die at a certain point.

Dr Coffey said people who have one or more alcoholic drinks per day will accelerate shrinkage. Smoking and high cholesterol are also thought to hurry it along.

Five year study

Dr Coffey used magnetic resonance imaging technology to measure the brain size of 330 healthy men and women. He noticed varying rates of shrinkage particularly among people in their 60s.

"Someone who's 65 might show a little, some might show a lot ... It's a lot like you see older folks behaving. You'll see someone who's sharp as a tack, another who can't find their car keys.

"We're trying to uncover what it is about the different sexes that relate to these different brain changes, and having discovered that, is there anything we can do to change that process?" he said.

The brain shrinkage and fluid increase were mostly seen in the frontal and temporal lobes, which control thinking, planning and memory.

Dr Coffey also found that women are better at holding on to verbal memories, while men are better at non-verbal skills, like map-reading or putting a puzzle together.