Two-month period of 500 mg lecithin-based delivery form of quercetin daily dietary supplementation counterbalances chronic fatigue symptoms: A double-blind placebo controlled clinical trial.

Background: Chronic fatigue (CF) is a complex phenomenon without clear etiology that may require long-term treatment, but to date, no specific therapy has been identified for it. Some botanicals might be helpful in the management of CF. Among these botanicals, quercetin demonstrates its capacity to modulate multiple biological pathways and acknowledged major properties in CF: antioxidant, anti-inflammatory, immunomodulating, improving exercise endurance, enhancing mitochondrial biogenesis, repairing mitochondrial dysfunction.

Purpose: Given this background, the aim of this study was to evaluate if a 2-month period of daily Quercetin Phytosome™ 500 mg supplementation is of benefit for the relief of CF.

Methods: The primary end point has been the evaluation of fatigue, by Fatigue Impact Scale (FIS-40). The secondary end points have been the assessment of sleep, by Pittsburgh Sleep Quality Index (PSQI), evaluation of muscle performance, by short physical performance battery and by wearable armband-shaped sensor in order to evaluate the number of steps, body composition, by DXA and quality of life by Short-Form 12-Item Health Survey (SF-12).

Results: Seventy-eight subjects (42 F; 36 M) (mean age 56 ± 9) reporting CF symptoms, completed the study (placebo/supplement 38/40). The FIS-40 mean difference changes between groups (supplement minus placebo) was - 10.583 points (CI95% -11.985; -9.182) (p < 0.001). Also, statistically significant changes between groups have been recorded in Pittsburgh Sleep Quality Index - 2.040 points (CI95%: -2.770; -1.309), p < 0.01), number of steps 1443.152 (CI95%: 1199.556; 1686.749), and SPPB (score) 0.248 (CI95%: 0.105; 0.391) (p < 0.001).

Conclusion: The quercetin supplementation counterbalances CF symptoms.