Compound reduced anxiety-like behavior after trauma in aged mice
Experiments in 15-month-old mice given hydroxytyrosol for 30 or 50 days also found more new neurons, but no improvement in distinguishing similar settings.
Limit: The main behavioral comparison involved only 10 mice per group
Edited by Boris Djordjevic · AgingResearch.News
In an animal experiment, researchers gave 15-month-old C57BL/6J mice hydroxytyrosol, a compound found in olive oil, in drinking water at 100 milligrams per kilogram of body weight daily for 30 or 50 days. Controls received plain water. A fear-discrimination task involving footshocks included 10 mice per group.
Hydroxytyrosol reduced heightened fear responses and anxiety-like behavior after the stressful experience, but did not improve discrimination between similar settings. It also increased new neuron production in both studied regions of the dentate gyrus, a brain area involved in memory, and reduced inflammation there. The compound preserved the stability of certain gut bacterial families. However, overall bacterial diversity and composition remained stable in both treated and untreated stressed mice.
Why it matters
New neuron production declines with age. The authors suggest that hydroxytyrosol may support resilience to traumatic stress in aging mice by increasing new neuron production and altering interactions between gut microbes and the brain.
Caveats
Researchers assigned groups by body weight without formal randomization, and the main behavioral comparison involved 10 mice per group. These mouse results do not establish effectiveness in people with posttraumatic stress disorder.
The paper
National Research Council
Journal of Neurochemistry, Apr 30, 2026, Open access
doi.org/10.1111/jnc.70448PubMed 42059580
Corrected, May 14, 2026
