Effects of Dark Chocolate Consumption on Anxiety, Depressive Symptoms and Health-related Quality of Life Status among Cancer Patients

Anxiety and depressive symptoms (AD) are common among cancer patients and have been shown to adversely affect their health-related quality of life (HRQoL). Dark chocolate is popular for its beneficial effects on mood regulations. This study aims to assess the effects of dark chocolate consumption on AD and the HRQoL status among cancer patients. A sample of 133 cancer patients was recruited from three public hospitals in the East Coast Peninsular of Malaysia. The AD was assessed by the Malay Hospital Anxiety and Depression Scale (HADS) while HRQoL was measured via the Malay McGill Quality of Life (MMQoL). Patients were randomly assigned to Intervention Group (IG, n=65) and Control Group (CG, n=68) whereby dark chocolate (50g) was administered to IG while CG consumed mineral water for three consecutive days. Data was analyzed descriptively and score comparisons were conducted using nonparametric tests. No significant difference in AD and HRQoL was detected at baseline between IG and CG (all p>0.05). At follow-up, significant changes in AD and Total MMQoL Score were demonstrated for both groups. Specifically, the AD was significantly reduced after dark chocolate consumption (mean difference: HADS-A= -4.3±2.6, HADS-D= -6.5±2.5 p<0.001). HRQoL-wise, the Total MMQoL Scores was significantly increased in IG compared to CG post-intervention (mean difference = 1.2±1.0, p<0.001). The IG patients who were anxious or depressed at baseline reported lower AD scores and enhanced HRQoL status at follow-up. These findings indicated that a 3-day dark chocolate consumption may reduce AD and thus also improved the HRQoL status in cancer patients.