Research from Saudi Arabia has revealed a concerning link between anxiety, insomnia, and reduced levels of natural killer (NK) cells in young women. Published in the journal Frontiers in Immunology, the study highlights how these mental health issues can impair immune function, potentially increasing susceptibility to various diseases.
Natural killer cells play a vital role in the immune system, acting as the body’s first line of defense against pathogens and infected cells. When their levels are diminished, the risk of immune dysfunction rises, which could lead to an array of health problems. With anxiety disorders and insomnia becoming increasingly prevalent, the study aimed to explore their impact on NK cell levels among young female university students.
Dr. Renad Alhamawi, an assistant professor of immunology and immunotherapy at Taibah University, led the investigation. She stated, “We found that in students with insomnia symptoms, the count and percentage of total NK cells and their sub-populations were declined.” Similarly, those with anxiety symptoms exhibited a lower number of circulatory NK cells compared to their symptom-free counterparts.
Study Overview and Findings
The study involved 60 female students, aged between 17 and 23 years old, who completed questionnaires assessing their sociodemographic data along with their anxiety and insomnia symptoms. The results were striking: approximately 53% of participants reported sleep disturbances indicative of insomnia, while 75% experienced anxiety symptoms. Among these, about 17% and 13% reported moderate and severe symptoms, respectively.
Participants also provided blood samples to measure NK cell levels. The results indicated that students with anxiety symptoms had a significantly lower percentage of circulatory NK cells and their subtypes. The severity of anxiety symptoms correlated with NK cell decline; those with moderate to severe anxiety had a notably reduced percentage of these vital immune cells.
In students exhibiting insomnia symptoms, higher anxiety scores were negatively associated with the proportion of total peripheral NK cells. This suggests that the dual burden of anxiety and insomnia can severely compromise immune function.
Implications for Health and Future Research
The implications of reduced NK cell levels are significant, as they can lead to increased vulnerability to diseases, including chronic conditions and mental health disorders such as depression. Dr. Alhamawi emphasized the importance of understanding how psychological stressors affect immune cell distribution and activity. She noted, “Understanding these mechanisms may provide valuable insights into the pathways underlying inflammation and tumorigenesis.”
Despite its important findings, the study has limitations. It focused exclusively on young women, a group disproportionately affected by anxiety and sleep disorders, which may limit the broader applicability of its results. Future research is essential to explore these associations across different demographics, including various age groups and genders.
Previous studies have shown that adopting healthy lifestyles—such as engaging in regular physical activity, practicing stress reduction techniques, and maintaining a balanced diet—can enhance NK cell function. Conversely, the effects of anxiety and insomnia disrupt multiple body systems and may contribute to chronic and inflammatory diseases, ultimately undermining health and quality of life.
The research underscores the need for holistic approaches to health that consider both mental and physical well-being. As Dr. Alhamawi concluded, “Such impacts ultimately compromise overall health and quality of life.”
For further details, the study can be accessed through DOI: 10.3389/fimmu.2025.1698155.
