Insomnia and anxiety may weaken immune system in young women: Study

New Delhi: Insomnia and anxiety may significantly weaken the immune system by reducing the body’s natural defence cells, according to a new study conducted among young women. The research suggests that mental health conditions such as poor sleep and persistent anxiety could leave individuals more vulnerable to infections and diseases.

Researchers from Taibah University in Saudi Arabia found that symptoms of insomnia and anxiety were associated with a lower number of natural killer (NK) cells—a crucial component of the immune system responsible for identifying and destroying pathogens, infected cells and even cancerous cells.

The study, published in the journal Frontiers in Immunology, analysed 60 female university students. Participants completed standardised questionnaires to assess levels of anxiety and sleep disturbances, while blood samples were collected to measure the concentration of natural killer cells in their bodies.

The findings revealed that young women reporting insomnia symptoms had a noticeably reduced total count of natural killer cells. Similarly, those experiencing anxiety showed lower levels of circulating NK cells, indicating compromised immune surveillance.

According to the researchers, nearly 75 per cent of participants exhibited symptoms of generalised anxiety disorder (GAD-7) at varying degrees of severity, while more than half reported problems related to insomnia. Students with anxiety symptoms were found to have both a lower percentage and reduced absolute numbers of circulating NK cells compared to those without such symptoms.

The decline was more pronounced among participants with moderate to severe anxiety, who showed a significant reduction in natural killer cells. In contrast, those with minimal or mild anxiety experienced only a marginal decrease. Among students suffering from insomnia, higher anxiety scores were closely linked to an even lower count of NK cells.

A reduced number of natural killer cells can impair immune function, potentially increasing the risk of infections, cancer and mental health conditions such as depression, the researchers noted.

The study highlights the close connection between mental health and immune health and may help scientists better understand how anxiety and sleep disorders affect the body at a physiological level. The findings could also contribute to improved prevention strategies for immune-related disorders and certain cancers, the researchers added.

(with inputs from agencies)