The Effects of Sucrose Consumption on Left-Frontal Asymmetry and Anger in Persons with Fibromyalgia Syndrome

Objectives: Previous studies suggest that a carbohydrate-restricted diet ameliorates chronic and idiopathic post-prandial [PP] mood symptoms in persons with fibromyalgia syndrome [FMS]. These studies, however, shed no light on the PP effects of carbohydrate on mood and its electroencephalographic correlates. The present study measured the effects of sucrose on electroencephalogram [EEG] and mood self-report measures in persons with FMS and age-matched healthy normal controls [HNC]. Methods: The present investigation sought to determine the relationships between reported mood, relative left-frontal EEG asymmetry [rLFA] in the alpha band, and blood glucose at baseline and four PP epochs following ingestion of pure sucrose in female participants with FMS [N = 8] and HNC [N = 10]. Results: The FMS and HNC showed equivalent patterns of blood glucose throughout the study, but FMS patients showed elevated levels of depression, anger, and other indicators of distress at all time points. An interaction emerged for high alpha [8-12 Hz] rLFA between experimental epoch and participant group, indicating increased rLFA for the FMS group at post-prandial 60 minutes. The pattern of increased rLFA correlated with anger for the FMS group only. At baseline, rLFA was negatively correlated with depressive sympomatology for the HNC group, and uncorrelated in the FMS group. Conclusions: Results support previous findings of decoupling of mood and EEG in persons with elevated depression levels, as well as a unique EEG response to carbohydrates for the FMS participants. These results are discussed in terms of an approach-withdrawal model of affect.