Association of dietary, circulating, and supplement fatty acids with coronary risk: a systematic review and meta-analysis.
BACKGROUND
Guidelines advocate changes in fatty acid consumption to promote cardiovascular health.


OBJECTIVE
To summarize evidence about associations between fatty acids and coronary disease.


METHODS
MEDLINE, Science Citation Index, and Cochrane Central Register of Controlled Trials through July 2013.


METHODS
Prospective, observational studies and randomized, controlled trials.


METHODS
Investigators extracted data about study characteristics and assessed study biases.


RESULTS
There were 32 observational studies (530,525 participants) of fatty acids from dietary intake; 17 observational studies (25,721 participants) of fatty acid biomarkers; and 27 randomized, controlled trials (103,052 participants) of fatty acid supplementation. In observational studies, relative risks for coronary disease were 1.02 (95% CI, 0.97 to 1.07) for saturated, 0.99 (CI, 0.89 to 1.09) for monounsaturated, 0.93 (CI, 0.84 to 1.02) for long-chain ω-3 polyunsaturated, 1.01 (CI, 0.96 to 1.07) for ω-6 polyunsaturated, and 1.16 (CI, 1.06 to 1.27) for trans fatty acids when the top and bottom thirds of baseline dietary fatty acid intake were compared. Corresponding estimates for circulating fatty acids were 1.06 (CI, 0.86 to 1.30), 1.06 (CI, 0.97 to 1.17), 0.84 (CI, 0.63 to 1.11), 0.94 (CI, 0.84 to 1.06), and 1.05 (CI, 0.76 to 1.44), respectively. There was heterogeneity of the associations among individual circulating fatty acids and coronary disease. In randomized, controlled trials, relative risks for coronary disease were 0.97 (CI, 0.69 to 1.36) for α-linolenic, 0.94 (CI, 0.86 to 1.03) for long-chain ω-3 polyunsaturated, and 0.89 (CI, 0.71 to 1.12) for ω-6 polyunsaturated fatty acid supplementations.


CONCLUSIONS
Potential biases from preferential publication and selective reporting.


CONCLUSIONS
Current evidence does not clearly support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of total saturated fats.


BACKGROUND
British Heart Foundation, Medical Research Council, Cambridge National Institute for Health Research Biomedical Research Centre, and Gates Cambridge.
Rajiv
R
Chowdhury
Samantha
S
Warnakula
Setor
S
Kunutsor
Francesca
F
Crowe
Heather A
HA
Ward
Laura
L
Johnson
Oscar H
OH
Franco
Adam S
AS
Butterworth
Nita G
NG
Forouhi
Simon G
SG
Thompson
Kay-Tee
KT
Khaw
Dariush
D
Mozaffarian
John
J
Danesh
Emanuele
E
Di Angelantonio
D015415:Biomarkers / Q000097:blood; D003327:Coronary Disease / Q000097:blood* / Q000453:epidemiology*; D018752:Diet, Fat-Restricted; D004041:Dietary Fats / Q000097:blood*; D019587:Dietary Supplements; D005227:Fatty Acids / Q000097:blood*; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage; D006801:Humans; D012307:Risk Factors
D015415:Biomarkers; D004041:Dietary Fats; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated