Review of select dietary supplement interventions for endothelial dysfunction

Abstract

Dietary supplements (DS) have been purported to affect endothelial function and reduce cardiovascular disease risk. A systematic PubMed search (January 2000 to July 2011) identified 586 clinical trials that utilized DS, along with a standardized vascular function measure, in healthy and at risk subjects. 56 randomized controlled trials met the selection criteria for folic acid, omega‐3 fatty acids, cocoa, and isoflavones. The review utilized scoring criteria for design quality (Jadad, 1996), DS test material quality (CONSORT botanical guidelines; Gagnier, 2006), and nutrient reporting guidelines (Chung, 2009). Preliminary results: mean Jadad scores were 3.62, 3.12, 3.33, 3.60 (out of 5), for folic acid, omega‐3 fatty acids, cocoa, and isoflavones, respectively. For DS receiving a CONSORT score, cocoa and isoflavones, 92.6% of papers reported the DS proprietary name, 44.4% reported dosage, duration, and rationale for dose used, and only 14.8% reported chemical analysis prior to use. All four DS received a nutrient quality score. 73.2% of the papers reported the DS source or supplier, 60.7% reported dosage and duration, 53.6% provided baseline nutrient biomarker assessment, and 32.1% provided baseline nutrient assessment. While Jadad scores were comparable across DS, nutrient quality scores ranked higher for cocoa and isoflavones compared to folic acid and omega‐3 fatty acids (p<0.05).