March 29, 2004 -- A compound derived from licorice root may help slow the effects of aging on the brain and keep mental skills sharp.
Researchers found the compound, known as carbenoxolone, appears to inhibit an enzyme in the brain that is involved in making stress-related hormones, which have been associated with age-related mental decline.
The study, published in the online early edition of the Proceedings of the National Academy of Sciences, showed daily supplementation with the compound improved verbal fluency in healthy elderly men and improved verbal memory in older adults with diabetes.
Although this was a small study and more research is needed to confirm the results, researchers say the licorice root compound may offer a new way to help prevent the normal decline in memory and other cognitive skills people experience as they grow older.
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Licorice Root May Fight Effects of Aging on Brain
Researchers say previous human and animal studies have shown that differences in cognitive function can be attributed to differences in long-term exposure to hormones produced by the adrenal glands, such as cortisol.
In the study, researchers examined whether inhibiting levels of an enzyme required to increase the activity of these hormones with the licorice root compound might have any effect on cognitive function.
A group of 10 healthy men aged 55-75 years and 12 older adults with diabetes were randomly assigned to take either 100 mg of carbenoxolone per day or a placebo. Neither group had dementia or other impairment, but had only the expected age-related changes in mental function.
After four weeks, researchers found healthy men that took the supplement performed better on a word association test that assessed their verbal fluency skills.
After six weeks of using the compound, the verbal memory skills among the people with diabetes improved, according to various list learning and paragraph recall tests.
Previous studies have suggested that the licorice root compound might increase insulin sensitivity and improve diabetes, but glucose control levels remained unchanged during the study in this group.
Cortisol levels in the blood also remained unchanged in the study. Researchers say those results suggest that carbenoxolone may act directly on brain cells and reduce the amount of the hormone circulating in the brain to prevent or slow age-related declines in cognitive function.