TY - JOUR
T1 - Evidence from randomised controlled trials did not support the introduction of dietary fat guidelines in 1977 and 1983
T2 - A systematic review and meta-analysis
AU - Harcombe, Zoë
AU - Baker, Julien S.
AU - Cooper, Stephen Mark
AU - Davies, Bruce
AU - Sculthorpe, Nicholas
AU - DiNicolantonio, James J.
AU - Grace, Fergal
PY - 2015/2/9
Y1 - 2015/2/9
N2 - Objectives: National dietary guidelines were introduced in 1977 and 1983, by the US and UK governments, respectively, with the ambition of reducing coronary heart disease (CHD) by reducing fat intake. To date, no analysis of the evidence base for these recommendations has been undertaken. The present study examines the evidence from randomised controlled trials (RCTs) available to the US and UK regulatory committees at their respective points of implementation. Methods: A systematic review and meta-analysis were undertaken of RCTs, published prior to 1983, which examined the relationship between dietary fat, serum cholesterol and the development of CHD. Results: 2467 males participated in six dietary trials: five secondary prevention studies and one including healthy participants. There were 370 deaths from allcause mortality in the intervention and control groups. The risk ratio (RR) from meta-analysis was 0.996 (95% CI 0.865 to 1.147). There were 207 and 216 deaths from CHD in the intervention and control groups, respectively. The RR was 0.989 (95% CI 0.784 to 1.247). There were no differences in all-cause mortality and non-significant differences in CHD mortality, resulting from the dietary interventions. The reductions in mean serum cholesterol levels were significantly higher in the intervention groups; this did not result in significant differences in CHD or all-cause mortality. Government dietary fat recommendations were untested in any trial prior to being introduced. Conclusions: Dietary recommendations were introduced for 220 million US and 56 million UK citizens by 1983, in the absence of supporting evidence from RCTs.
AB - Objectives: National dietary guidelines were introduced in 1977 and 1983, by the US and UK governments, respectively, with the ambition of reducing coronary heart disease (CHD) by reducing fat intake. To date, no analysis of the evidence base for these recommendations has been undertaken. The present study examines the evidence from randomised controlled trials (RCTs) available to the US and UK regulatory committees at their respective points of implementation. Methods: A systematic review and meta-analysis were undertaken of RCTs, published prior to 1983, which examined the relationship between dietary fat, serum cholesterol and the development of CHD. Results: 2467 males participated in six dietary trials: five secondary prevention studies and one including healthy participants. There were 370 deaths from allcause mortality in the intervention and control groups. The risk ratio (RR) from meta-analysis was 0.996 (95% CI 0.865 to 1.147). There were 207 and 216 deaths from CHD in the intervention and control groups, respectively. The RR was 0.989 (95% CI 0.784 to 1.247). There were no differences in all-cause mortality and non-significant differences in CHD mortality, resulting from the dietary interventions. The reductions in mean serum cholesterol levels were significantly higher in the intervention groups; this did not result in significant differences in CHD or all-cause mortality. Government dietary fat recommendations were untested in any trial prior to being introduced. Conclusions: Dietary recommendations were introduced for 220 million US and 56 million UK citizens by 1983, in the absence of supporting evidence from RCTs.
UR - http://www.scopus.com/inward/record.url?scp=84983003384&partnerID=8YFLogxK
U2 - 10.1136/openhrt-2014-000196
DO - 10.1136/openhrt-2014-000196
M3 - Review article
AN - SCOPUS:84983003384
SN - 2053-3624
VL - 2
JO - Open Heart
JF - Open Heart
IS - 1
ER -