OBJECTIVE

Few peripheral metabolites have been shown to be associated with mood in healthy individuals or patients with central nervous system diseases. During military basic combat training (BCT), mood state, physical performance and body composition substantially improve, providing an opportunity to examine relationships between mood and nutritional and hormonal biomarkers.

METHODS

Thirty-five females enrolled in U.S. Marine BCT, an intense physically and mentally challenging 12-week course, were studied. Every 4 weeks, mood was assessed with the Profile of Mood States (POMS), as were nutritional, metabolic and hormonal plasma markers.

RESULTS

Mood and fitness improved over BCT, and there were substantial changes in biochemical markers. Multiple regression demonstrated that, in combination, cholesterol (HDL, LDL), fructosamine, triglycerides, free fatty acids (FFA), dehydroepiandrosterone-sulfate (DHEA-S), ACTH, and substance P accounted for 44% of variation in anxiety, 40% confusion, 37% fatigue, 27% depression and 40% in total mood (p < .0001). Increased HDL, FFA, DHEA-S, and substance P were associated with degraded mood (p < .05). Increased LDL, triglycerides, fructosamine, and ACTH were associated with improved mood (p < .05). Other markers, including glucose, cortisol, and C-reactive protein were not associated with mood.

CONCLUSIONS

Normal human mood state was associated with 8 plasma markers. Increased HDL and lower LDL, which are associated with improved cardiovascular status, were associated with negative affect. Fructosamine and substance P, not previously known to be related to mood, were associated with it. We are not aware of any biological parameters that in aggregate predict such a substantial proportion of variation in normal mood.