How Early Does Cognitive Decline Begin? Earlier Than You Think

Chris Parfitt

Those who think signs of cognitive decline start around age 60, a new study has some unwelcome news: Brain function could start lessening beginning at age 45.

The research, published in the British Medical Journal, involved giving cognitive tests to 5,198 men and 2,192 women ages 45 to 70 three times over the course of a decade, reports the L.A. Times. The tests evaluated memory, reasoning, vocabulary, and visual and hearing comprehension.

Declines were seen in all areas except vocabulary, and as people got older, there was a faster drop. Over the 10 years, men ages 45 to 49 experienced a 3.6 percent decline in mental reasoning. Those 65 to 70 saw a 9.6 percent drop.

Women ages 45 to 49 had the same decline as men -- 3.6 percent -- with a 7.4 percent decline by the time they reached ages 65 to 70.

Previous research had suggested that cognitive decline didn't set in until about age 60, but the study's authors noted that this point of view has not been universally accepted.

They wrote that if these declines are happening sooner, as their study suggests, maintaining a healthy lifestyle earlier in life is critical.

That means using diet and exercise

to control diabetes and reduce the risk of cardiovascular disease, both of which have been linked to a higher risk of dementia and Alzheimer's.

"There is emerging consensus that 'what is good for our hearts is also good for our heads,' " they wrote.

As life expectancy continues to increase, the authors said, understanding cognitive aging will be "one of the challenges of this century."

Even more importantly, they added, efforts to convince people to improve their health and lifestyle needs to be targeted at younger ages.

Photo credit: Chris P. via flickr.com