Job stress may be doing more than raising your blood pressure — it could be aging your brain more quickly and causing poor memory.

Colorado State University researchers found older workers with high levels of job stress had smaller volumes in a certain part of the brain than people with less stress. The study’s high-stress participants also did not perform as well on memory tasks.

It is the first time that job stress has been associated cognitive and brain aging. The findings appeared recently in the journal Frontiers in Human Neuroscience.

The research focused on physical demands at work such as lifting boxes or moving heavy items. Because leisure-time aerobic exercise has found to be beneficial, the researchers also introduced controls in the study to account for those activities.

During the study, they evaluated job habits and brain-imaging data from adults age 60 to 79 years old with normal cognition.

What they found was a clear difference: People who did physical activity in their leisure time had a larger hippocampus, the part of the brain that is associated with learning, emotions and formation of new memories. Among those who faced physical stress at work, hippocampus volume tended to be smaller. Job complexity and psychological work stress did not appear to be contributing factors.

The findings are somewhat new territory: Most approaches to cognitive decline have focused on leisure-time exercise and interventions — not the potentially negative effects of job stress.

Because caring for people with cognitive impairment is so expensive, researchers say the findings could have a major impact if brain health can be better supported in middle-age workers.