“…Fifty‐four studies met the inclusion criteria. Study designs included: n = 13 RCT’s, 23,25,31,38,42,49,55,56,61,62,70,73,77 n = 37 cohort studies, 20‐22,24,26‐30,32‐37,39‐41,43,45,47‐49,51‐54,57‐60,64,66‐68,71,72 n = 2 case‐control studies, 44,63 n = 1 nonintervention case series study 46 and n = 1 nonrandomized cross‐sectional over trial 65 . Four authors reported results of the same study in different papers 21,22,39,40,45,47,49,50 and therefore results from these studies were described, but only one set of each results was used within any meta‐analysis.…”