chowdhury et al, 2014, ann int med
DESCRIPTION
Association of Dietary, Circulating, and Supplement Fatty Acids With Coronary Risk A Systematic Review and Meta-analysis. Chowdhury et al, 2014, Ann Int Med. (Quick) paper summary. Aim: Associations between fatty acids and coronary disease Method: Meta-analysis of prospective trials - PowerPoint PPT PresentationTRANSCRIPT
Association of Dietary, Circulating, and
Supplement Fatty Acids With
Coronary RiskA Systematic Review and Meta-analysis
Chowdhury et al, 2014, Ann Int Med
(Quick) paper summary• Aim: Associations between fatty acids and
coronary disease• Method: Meta-analysis of prospective trials
• Dietary FA intake• Biomarkers of plasma FAs• Intervention (supplementation) trials
• Results (later)• Conclusions: ”Evidence does not clearly
support CV guidelines that encourage high consumption of polyunsaturated FAs, and low consumption of total SFAs”
Media interpretation of the paper
Media dramatization of the paper
Scientist backlash?• Complaints• Controversy • Calls (for retraction):
Not universal…..
Resolution to the 3-way
Proposed resolution
1. Consider the history of the paper2. Read the results3. Consider the methodology
• What was done• What was not done
4. Consider the original studies5. Consider other research
1. History of the paper
2. Read the results• (now there is a novelty).
2. Read the results• Plasma SFAs
2. Read the results• Plasma MUFAs
2. Read the results• Plasma PUFAs (ω-3)(remember – EVERYTHING we knew about diet was wrong).
2. Read the results• Plasma PUFAs (ω-6)
2. Read the results• Intervention (supplementation) trials
2. Read the results• Self-reported habitual intake of total SFA
not associated with cardiac events• Self-reported habitual intake of total MUFA
not associated with cardiac events• Self-reported habitual intake of α-linolenic
not associated with cardiac events• Self-reported habitual intake of LC ω-3
protective• Self-reported habitual intake of Total ω -6
not associated with cardiac events• Total trans fat associated
2. Read the results• Plasma SFAs: only 17:0 protective. 14:0;
15:0, 16:0, 15:0, 18:0 not associated• Total MUFA not associated• All LC ω-3 strongly protective individually• No evidence that total LC ω -3 associated• Protective effect of ARA, no association
with other ω-6
2. Read the results• Intervention trials showed no effect of
supplementation for α-linolenic, total LC ω-6, or ω-6
My first conclusions• Different FAs have different associations
with outcomes• Those most associated with a protective
effect have not been measured in the diet, nor studied in interventions
• But, no evidence that total saturated fat (intake / plasma) associated with events
• Convincing evidence that some ω-3 protective, although this has not been studied in an intervention trial.
In defense of the authors:• … do not clearly support .. guidelines that
promote high consumption of ω-6 PUFA and … reduced consumption of SFA
• LC ω -3 PUFAs in primary prevention• odd-chain SFAs (…milk or dairy
consumption) may have less deleterious effects
3. Consider the methodology
The development of cardiac events
The development of cardiac events
3. Consider the methodlogy
3. Consider the methodology
• Nutrient density substitution models convey information on dietary substitution; associations do not.
4. Consider the original samples• Timeframe• Participants & baseline characteristics• Event rate was up to 42%
Acknowledgements• Dariush Mozaffarian*• Brian Steffen*• American Heart Association*
*The views expressed in this presentation are not necessarily the views of the organizations / individuals
Further discussion• Is this an irresponsible paper? • If so – who was irresponsible?• Should we reconsider guidelines on
saturated fat?• Do YOU know what the guidelines are?• What about other outcomes?• The role of carbohydrates