July 12th, 2010
04:42 PM ET
Having a big brain is not just fodder for bragging about how smart you are. According to a new study, it may also mean less chance of developing Alzheimer's disease symptoms later in life.
The research, published today in the journal Neurology, found that among patients with Alzheimer's disease symptoms, those who had larger brains did better on cognitive tests - meaning their memory, and their ability to think and understand, was better.
"At the same level of brain atrophy or brain damage, patients with larger heads have better cognitive performance, so they somehow offset those symptoms related to brain damage," said Dr. Robert Perneczky, lead study author and a psychiatrist at the Technical University of Munich in Germany.
Researchers administered cognitive tests and brain scans to 270 patients with symptoms of Alzheimer's disease. The patients' head circumference was measured (as a proxy for brain size, since big heads tend to house big brains) and compared the severity of the brain damage with the scores on cognitive tests.
The fascinating finding - if you were to compare two brains with the same level of nerve cell death, the same level of damage, the same amount of missing brain matter - the person with the big brain would win out in the cognitive testing.
The key may be something called brain reserve, the brain's ability to compensate for brain damage. People with larger heads - and hence larger brains - most likely have more of it. "More brain reserve means that an individual can cope better with nerve cell loss as in with Alzheimer's disease," said Perneczky.
It may be that a larger brain has more matter to give, so that the loss of nerves and synapses (those trusty conveyors of information and memories) is not as potent. Another theory is that that surplus brain tissue may allow the brain to find alternative routes for information by laying down new pathways and networks for information.
All of this is great news for folks who are blessed with genetically big brains, but is there hope for the rest of us? Turns out that the key to having a big brain starts with how you develop during early childhood.
"Our results...underline the importance of optimal neurologic development in early life," said study authors. "Brain size reaches 93 percent of its final size at age 6, and therefore measurements of head circumference mainly reflect brain growth during the first few years."
That means not just genetics, but how we nurture a developing child's brain development, could have implications in the twilight of life when cognitive decline sets in. Proper nutrition and more obvious brain-stimulating activities like cuddling, playing with, and talking to your child are high on the list. (Click here for a guide to healthy child brain development from the Centers for Disease Control and Prevention).
Where does that leave those of us over the age of 6? Experts believe that living an active lifestyle may help to fend off Alzheimer's disease. That means eating a healthy diet, exercising, keeping up a healthy social life and doing "brain exercises" like reading and doing crossword puzzles.
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Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.