Lifestyle, Jan 2: Anxiety and sleep problems such as insomnia may be linked to a reduction in key immune cells, potentially leaving the body less capable of fighting disease, according to a new study conducted among young women.
Researchers from Taibah University in Saudi Arabia found that symptoms of anxiety and insomnia were associated with lower levels of natural killer (NK) cells — a crucial component of the immune system responsible for identifying and destroying pathogens, infected cells and abnormal cells.
The study, published in Frontiers in Immunology, involved 60 female university students. Participants completed standardised questionnaires to assess anxiety levels and sleep quality, while blood samples were analysed to measure NK cell counts.
The results showed that students reporting insomnia had a lower overall number of natural killer cells. Those experiencing anxiety symptoms had fewer NK cells circulating in their bloodstream, with the most pronounced decline observed among participants with moderate to severe anxiety.
Researchers noted that around 75 per cent of participants showed symptoms of generalised anxiety disorder to varying degrees, while more than half reported experiencing insomnia. Students with higher anxiety scores consistently exhibited reduced NK cell levels, especially when anxiety and insomnia occurred together.
A decline in natural killer cells can weaken immune defences and may increase susceptibility to infections, cancer and certain mental health conditions, including depression, the researchers said.
The findings highlight how mental health challenges and sleep disturbances can have direct physiological effects on the immune system. The research team said the study could help inform future strategies aimed at preventing immune-related illnesses and certain cancers by addressing anxiety and sleep disorders early.
