In addition to biological factors, lifestyle choices play an important role in the association between mental health and chronic, low-grade inflammation, found a new study published in the journal Brain, Behavior, and Immunity.
The research is based on the Moli-sani Study which includes over 24,000 people from a small region in central Italy called Molise, and utilises a wealth of psychometric scales, lifestyle/medical information, and blood markers.
“This may give us important information on the underpinnings of a number of chronic health conditions like cancer, cardiovascular disease and diabetes, which are often comorbid with depression and represent a notable burden in terms of public health in Western societies,” said co-author on the study Alessandro Gialluisi.
Combing through the data, Gialluisi and his team found that low-grade inflammation is not only robustly correlated with depressive symptoms and reduced overall mental well-being, but also depends – at least in part – on lifestyle factors, such as smoking, physical activity, and diet.
“It looks quite clear that lifestyle influences the relationship between systemic inflammation and depressive symptoms and (to a lesser extent) mental wellbeing. On the other hand, being affected by chronic health conditions did not seem to have a significant influence on this link,” explained Gialluisi.
After taking lifestyle factors out of the equation, certain biomarkers of inflammation were found to retain their entanglement with mental health, which suggests that genetics and/or other biological factors may also be at play.
Limitations of the study include its cohort, rather than longitudinal, nature (which is not conducive to causal inference), as well as the lack of proposed biological mechanisms, although that has more to do with the paucity of knowledge in this area overall.
On the last point, Gialluisi and his team are currently working on potential molecular and genetic mechanisms, and making further inroads into the role of low-grade inflammation with regards to depressive symptomatology.
“We are currently further investigating the link between low-grade systemic inflammation and mental health, especially its genetic and molecular bases and the implications on the risk of chronic conditions which are highly comorbid with depression. We will hopefully have new results ready for publication soon, so stay tuned,” promised Gialluisi.