Saturated Fat The Cochrane Collaboration 2012 Review

Hooper L, Summerbell CD, Thompson R, et al. Reduced or modified dietary fat for preventing cardiovascular disease. Cochrane Database Syst Rev. 2012;5:CD002137.

It should be noted though that none of the subgroups are statistically significant

Note: Total Mortality should always be taken into consideration

Sensitivity Analyses

Excluding studies with systematic difference in care (Overall Analysis)

Nine Data-Sets Included: Veterans Admin 1969 (1), Rose 1965 (1), NDHS (4), Minnesota Coron (2), PREMIER 2003 (1).

Excluding studies with systematic differences in diet other than fat (Overall Analysis)

Fourteen Data-Seta Included: Veterans Admin 1969 (1), Rose 1965 (1), NDHS (4), Minnesota Coron (2), MRC 1968 (1), Houtsmuller 1979 (1), Ball 1965 (1), Black 1994 (1), Ley 2004 (1), DART 1989 (1).

Excluding studies with systematic differences in diet other than fat (Modified Fat intake) (Excludes Oslo Diet-Heart 1966)

Excluding studies with systematic differences in diet other than fat (Reduced and Modified Fat intake) (Included: DART 1989 and NDHS Open)

Studies of at least two years duration

Eleven Data-Sets Included: Veterans Admin 1969 (1), Oslo Diet-Heart 1966 (1), MRC 1968 (1), Ball 1965 (1), Ley 2004 (1), DO IT 2006 (1), STARS 1992 (1), MeDiet 2002 (1), Houtsmuller 1979 (1), WHI (2). Eight at high risk for systematic differences in care (unclear risk in two), and six at high risk for dietary differences other than fat, including two studies with significant weight differences between groups.

Similar considerations apply to the other few significant subgroup findings for combined cardiovascular events

Most objective analysis - modified fat intake subgroup for the endpoint of total mortality: seven data-sets totaling over 1000 deaths, five at low risk for systematic differences in care, all at low risk for dietary differences other than fat, and included three double blinded trials.

Meta-regression

Note: This analysis excluded the Finnish Mental Hospital

Hooper’s review did not have information at the time for cause-specific endpoints from a trial where CHD/CV events were increased in the unsaturated fat group: Ramsden CE, Hibbeln JR, Majchrzak SF, Davis JM. n-6 fatty acid-specific and mixed polyunsaturate dietary interventions have different effects on CHD risk: a meta-analysis of randomised controlled trials. Br J Nutr. 2010;104(11):1586-600.

Conclusions:

• Changes in dietary fat had no effect on total mortality and cardiovascular mortality. This was also true of every sensitivity and subgroup analysis.• A statistically significant finding was found for the composite endpoint

“combined cardiovascular events”, which included softer events more susceptible to bias, and the significance of which disappeared in sensitivity analyses.• There were no significant reductions in any individual outcome (total

or non-fatal myocardial infarction, stroke, cancer deaths or diagnoses, diabetes diagnoses).