Recent research results suggest that long-term exposure to adrenal stress hormones may boost brain aging in later life.

Writing in the journal Nature Neuroscience, scientists at the University of Kentucky in Lexington looked at the results of memory tests taken by elderly patients with high levels of the stress hormone cortisol, released by adrenal glands when the body is stressed. That high-level group scored lower than others with reduced levels of the hormone, researchers say.

The level of hormone released apparently affects the total volume of the brain's hippocampus -- a major source of recall and memory function -- in later life. Those with high levels had a hippocampus volume 14 percent less than those with lower levels, researchers found.

The study results suggest "chronic stress may accelerate hippocampal deterioration," said the researchers.