Summary
A study by researchers at Texas A&M University College of Medicine has found that shift work schedules causing circadian rhythm dysregulation during early adulthood can accelerate cognitive decline in middle age. Using an animal model, the study revealed that disruptions in circadian rhythms led to earlier memory and learning deficits and long-term neuroinflammation. These findings suggest that shift work may be an independent risk factor for cognitive impairment and neurodegenerative diseases. Future research will focus on treatments targeting immune cell regulation to mitigate these effects.
Key Takeaways
- Shift Work and Accelerated Cognitive Decline: Circadian rhythm dysregulation caused by shift work during early adulthood significantly accelerates cognitive decline by middle age, earlier than typically expected.
- Neuroinflammation and Brain Health: Disrupted circadian rhythms are linked to long-term changes in immune cells and microglia in the brain, driving inflammatory processes associated with neurodegenerative diseases.
- Potential Interventions: Future studies will explore immune cell-targeted treatments to address the impact of circadian rhythm dysregulation on cognitive aging.
Shift work may have lasting effects on cognitive health, according to researchers at Texas A&M University College of Medicine, who have published a study exploring possible links between dysregulation of circadian or 24-hour body rhythms and cognitive impairment during aging in the Journal of Neuroinflammation.
Conducted by David Earnest, PhD, Karienn de Souza, PhD, and M. Karen Newell-Rogers, PhD, the study indicates that circadian rhythm alterations in response to shift work-like schedules during early adulthood persisted into middle age.
According to Earnest, past clinical literature suggests that people with abnormal work or social schedules are more susceptible to an array of health disorders, including cardiovascular disease, diabetes, and cancer. With De Souza’s expertise in cognition and aging and Earnest’s in how internal body clocks control circadian rhythms and sleep, Earnest says discussions naturally veered toward expanding upon previous research to explore the potential link between shift work and health later in life, specifically related to memory and cognitive decline.
Focus on Early Adulthood and Shift Work Schedules
Earnest says he and de Souza used an animal model to focus this research on the time of life equivalent of young adults aged 18–26—when people are most likely to engage in shift work based on human demographics.
“We were interested in following up on our previous observations examining associations between age-related changes in cognition and circadian rhythms to determine whether or not circadian rhythm dysregulation by itself is a long-term risk factor for accelerated cognitive decline later in life,” Earnest says in a release.
Results indicate circadian rhythm dysregulation dramatically accelerates cognitive decline at middle age—much earlier than learning and memory deficits usually occur—and is linked with long-term alterations in the regulation of immune cells and cells in the brain called microglia that contribute to inflammatory processes associated with neurodegenerative diseases.
Implications for Preventing Neurodegenerative Diseases
In turn, these findings suggest shift-work-related dysregulation of circadian rhythms, independent of aging and other variables associated with dementia, is a long-term risk factor for activation of neuroinflammatory immune cells and accelerated decline in learning and memory during aging.
Earnest believes this study illuminates critical information in the fight to prevent, treat, and cure dementia. “I’ve published a lot of studies in my research career over the last 35 years,” Earnest says in a release. “But this might be some of the most significant research findings I’ve published in my life.”
Future studies will examine the possible impact of treatments targeting the regulation of different immune cells to modulate the impact of circadian rhythm dysregulation on cognitive decline later in life.
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