Major depressive disorder is a widespread condition that affects daily functioning, worsens other health issues, and lowers quality of life. While a high-salt diet has been linked to depression, the exact connection or cause is still unknown.
A new study suggests that a high-salt diet (HSD) induces depression-like symptoms in mice. High-salt diet produces a protein called IL-17A, which acts as a contributor to depression.
This study highlights salt reduction as a potential way to prevent mental illness. It also opens doors to new treatments targeting IL-17A to address depression.
Researchers found that gamma-delta T cells (γδT cells) are a significant source of IL-17A in mice fed a high-salt diet, producing about 40%. Removing these cells greatly reduced depression-like symptoms, suggesting another possible treatment option.
High salt intake is widespread in the Western diet, with fast foods often containing much more salt than home-cooked meals. This is a public health concern, as high-salt diets (HSD) are linked to diseases like heart issues, autoimmune disorders, and neurodivergent conditions.
Major depressive disorder, another major public health issue affecting 15-18% of people, has also been associated with HSD, though its exact role in causing depression was unclear.
In this study, researchers fed mice a normal diet or an HSD for five weeks. Compared to the mice on a normal diet, the mice on the high-salt diet showed signs of depression-like behavior, such as reduced exploration and increased inactivity. This suggests a connection between excessive salt intake and depressive symptoms.
The team also investigated whether HSD induced IL-17A production in mice in this study. A high-salt diet (HSD) raises IL-17A levels in the spleen, blood, and brain, which is linked to anxiety and depression-like behaviors.
However, mice that couldn’t produce IL-17A didn’t show these symptoms, confirming its role in depression-like effects. These results align with evidence showing HSD is linked to severe depression, while low sodium intake is associated with better mood.
Researchers hope this inspires more studies into immune-related causes of depression and leads to treatments targeting IL-17A or γδT cells. Dr. Chen’s team plans to validate these findings in humans and explore how HSD activates γδT17 cells.
Journal Reference
- Di Lu, Wenjie Chen, Wenhui Sun, Chuan Wei, Xuan Xie, Na Li, Haiyan Yan, Ying Chen, Yue Wu, Zhigang Lei et al. High-salt diet drives depression-like behavior in mice by inducing IL-17A production. The Journal of Immunology. DOI: 10.1093/jimmun/vkaf019
Source: Tech Explorist
