Depression inhibits the anti-inflammatory effects of leisure time physical activity and light to moderate alcohol consumption.

Light to moderate alcohol consumption and leisure time physical activity (LTPA) are independently associated with lower levels of high sensitivity C-reactive protein (CRP), a predictor of cardiometabolic risk. In contrast, depression, ranging from low mood disturbance to major depressive disorder, has been associated with elevated CRP. To test the hypothesis that depression attenuates the anti-inflammatory effects of LTPA and alcohol consumption, the current study tested the moderating effect of severity of depressive symptomatology on the relation of alcohol consumption and LTPA to CRP in 222 healthy adult men and women (18-65 years of age). Given the known effects of gender on inflammation, we also examined the effects of gender on the tested interactions. Depression was assessed using the Beck Depression Inventory. Frequency of alcohol consumption, hours of LTPA per week and other coronary risk/protective factors were assessed via self-report and structured interview. Fasting blood samples were used to measure CRP and lipids. As predicted, the interaction between LTPA and depressive symptomatology was significant (F=5.29, p<.03) such that lower CRP was associated with the combination of decreased depressive symptomatology and increased LTPA. Among those with increased depressive symptoms, increased LTPA was not associated with higher CRP. Similarly, depression interacted with alcohol consumption in predicting CRP in men but not women (F=5.03, p<.008) such that for men light to moderate alcohol consumption was associated with lower CRP but only among those with decreased depressive symptoms. Light to moderate alcohol consumption was not associated with lower CRP in those with increased depressive symptom severity. The pattern of the interactions between anti-inflammatory activities such as light to moderate alcohol consumption and LTPA and psychological distress as indexed by severity of depressive symptomatology suggests an important new avenue for future research.