A Randomized Controlled Trial to Determine the Effects of Curcumin and Epigallocatechin Gallate Supplementation on Serum Brain Derived Neurotrophic Factor and Mood Disturbance in Adults

Abstract

Mood disorders such as depression, anxiety, stress, and sleep disturbances are becoming increasingly prevalent. Brain-Derived Neurotrophic Factor (BDNF), a neurotrophin involved in neuroplasticity and neuronal health, has emerged as a promising biomarker associated with psychiatric and mood related conditions. The research on and use of alternative treatments for such conditions are increasing with nutritional compounds like epigallocatechin-3-gallate (EGCG) and curcumin demonstrating potential neuroprotective and mood-modulating effects. This study aimed to evaluate the impact of supplementation with these two compounds on mood disorder symptomology and serum BDNF in a young adult population with moderate depression symptoms. This was a randomized double-blinded placebo-controlled trial (RCT) where eligible participants were randomized to consume EGCG (350mg/day) and curcumin (1,330mg/day) or placebo capsules for 8-weeks. Mood outcomes were measured using the Depression, Anxiety and Stress Scale (DASS-21) and Generalized Anxiety Disorder (GAD-7), sleep was assessed using the Global Sleep Assessment Questionnaire (GSAQ), and physical activity was measured with the International Physical Activity Questionnaire (IPAQ), all assessed at baseline, Week 4 and Week 8 with dietary intake and serum BDNF measured at baseline and Week 8. Individuals that were ineligible for the RCT due to low DASS-21 scores (controls) were recruited and matched to case participants by age, sex, and race for a case-control study. Results indicated significant improvements in mood (DASS-21 Composite, DASS-21 Depression, DASS-21 Stress, DASS-21 Anxiety, GAD-7, p < .001 for all), sleep (p < .001) and physical activity scores (p < .01) across all RCT participants with no significant difference between supplement and placebo groups. Mean serum BDNF levels did increase on average over the intervention in both groups but not to a statistically significant amount with no group by time interactions found. Correlation analysis revealed significant positive correlations between sugar intake (g/kg body weight) and mood symptoms in the intervention group at Week 8, further highlighting dietary impacts on mental health. Healthy Eating Index (HEI) scores for fruit and vegetable intake were included to control for dietary polyphenol intake. Higher baseline fruit and vegetable intake was associated with lower depression, anxiety, and stress scores at select timepoints. However, changes in fruit and vegetable intake during the intervention were not significantly related to changes in mood symptomology, which suggests that dietary improvements did not account for any mood changes that were observed over the 8-week period. In the case-control study, the cases group had significantly higher mood disturbance scores compared to the matched controls (DASS-21 Composite and all subscales, as well as GAD-7, p < .001 for all). Physical activity levels of the cases group were significantly lower than the controls (p < .037). There were significant differences found in serum BDNF between the groups, with cases showing significantly lower levels versus controls (p <.001). Healthy Eating Index (HEI) scores in the case-control analysis showed that baseline fruit and vegetable intake did not significantly predict mood symptom severity with no differences in diet quality observed between cases and controls. This indicates comparable baseline dietary pattern with minimal confounding from polyphenol intake in mood outcome comparisons. This study found that although the supplement group demonstrated significant reductions in mood disturbance and sleep disturbance scores, concurrent improvements in the placebo group indicate that the supplement had no effect. Several factors may have contributed to these null results and can be addressed in future studies. Additional research is warranted to delineate the specific roles of EGCG and curcumin, particularly in relation to BDNF modulation.