The reporting quality of SRs has improved 3 y after publication of SR reporting st and ards , but the reporting of nutrition variables has not .
Improved adherence to consensus methods and reporting st and ards should improve the utility of nutrition SRs
BACKGROUND The quality of nutrition-related systematic review s ( SRs ) is an unstudied but important factor affecting their usefulness .
OBJECTIVES The objectives were to evaluate the reporting quality of published SRs and to identify areas of improvement .
Higher baseline serum concentrations of vitamin E are associated with lower total and cause-specific mortality in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study.
BACKGROUND A meta- analysis of 19 trials suggested a small increase in the risk of all-cause mortality with high-dose vitamin E supplementation . Little is known , however , about the relation between mortality and circulating concentrations of vitamin E result ing from dietary intake , low-dose supplementation , or both . OBJECTIVE We examined whether baseline serum alpha-tocopherol concentrations are associated with total and cause-specific mortality . DESIGN A prospect i ve cohort study of 29 092 Finnish male smokers aged 50 - 69 y who participated in the Alpha-Tocopherol , Beta-Carotene Cancer Prevention ( ATBC ) Study was carried out . Fasting serum alpha-tocopherol was measured at baseline by using HPLC . Only 10 % of participants reported vitamin E supplement use at baseline , and thus serum concentrations of vitamin E mainly reflected dietary intake and other host factors . Risks of total and cause-specific mortality were estimated by using proportional hazards models . RESULTS During up to 19 y of follow-up , 13 380 deaths ( including 4518 and 5776 due to cancer and cardiovascular disease , respectively ) were identified . Men in the higher quintiles of serum alpha-tocopherol had significantly lower risks of total and cause-specific mortality than did those in the lowest quintile [ relative risk ( RR ) = 0.82 ( 95 % CI : 0.78 , 0.86 ) for total mortality and 0.79 ( 0.72 , 0.86 ) , 0.81 ( 0.75 , 0.88 ) , and 0.70 ( 0.63 , 0.79 ) for deaths due to cancer , cardiovascular disease , and other causes , respectively ; P for trend for all < 0.0001 ] . Cubic regression spline analysis of continuous serum alpha-tocopherol values indicated greater risk reductions with increasing concentrations up to approximately 13 - 14 mg/L , after which no further benefit was noted . CONCLUSION Higher circulating concentrations of alpha-tocopherol within the normal range are associated with significantly lower total and cause-specific mortality in older male smokers
The reporting quality of SRs has improved 3 y after publication of SR reporting st and ards , but the reporting of nutrition variables has not .
Improved adherence to consensus methods and reporting st and ards should improve the utility of nutrition SRs
BACKGROUND The quality of nutrition-related systematic review s ( SRs ) is an unstudied but important factor affecting their usefulness .
OBJECTIVES The objectives were to evaluate the reporting quality of published SRs and to identify areas of improvement .