Sherrie
26-12-2010, 08:24 AM
n-6 Fatty acid-specific and mixed polyunsaturate dietary interventions have different effects on CHD risk: a meta-analysis of randomised controlled trials
Christopher E. Ramsden et al
Randomised controlled trials (RCT) of mixed n-6 and n-3 PUFA diets, and meta-analyses of their CHD outcomes, have been considered decisive
evidence in specifically advising consumption of ‘at least 5–10% of energy as n-6 PUFA’.
Here we (1) performed an extensive literature search and extracted detailed dietary and outcome data enabling a critical examination of all RCT that increased PUFA and reported relevant CHD outcomes; (2) determined if dietary interventions increased n-6 PUFA with specificity, or increased both n-3 and n-6 PUFA (i.e. mixed n-3/n-6 PUFA diets); (3) compared mixed n-3/n-6 PUFA to n-6 specific PUFA diets on relevant CHD outcomes in meta-analyses; (4) evaluated the potential confounding role of trans-fatty acids (TFA).
n-3 PUFA intakes were increased substantially in four of eight datasets, and the n-6 PUFA linoleic acid was raised with specificity in four datasets. n-3 and n-6 PUFA replaced a combination of TFA and SFA in all eight datasets. For non-fatal myocardial infarction (MI) þ CHD death, the pooled risk reduction for mixed n-3/n-6 PUFA diets was 22% (risk ratio (RR) 0·78; 95% CI 0·65, 0·93) compared to an increased risk of 13% for n-6 specific PUFA diets (RR 1·13; 95% CI 0·84, 1·53).
Risk of non-fatal MI þ CHD death was significantly higher in n-6 specific PUFA diets compared to mixed n-3/n-6 PUFA diets (P¼0·02). RCT that substituted n-6 PUFA for TFA and SFA without simultaneously increasing n-3 PUFA produced an increase in risk of death that approached statistical significance (RR 1·16; 95% CI 0·95, 1·42).
Advice to specifically increase n-6 PUFA intake, based on mixed n-3/n-6 RCT data, is unlikely to provide the intended benefits, and may actually increase the risks of CHD and death.
Full Text: Christopher E. Ramsden, Joseph R. Hibbeln, Sharon F. Majchrzak and John M. Davis (2010). <i>n</i>-6 Fatty acid-specific and mixed polyunsaturate dietary interventions have different effects on CHD risk: a meta-analysis of randomised controlled trials. British Journal of Nutrition, 104, pp 1586-1600 doi:10.1017/S0007114510004010 (http://www.canibaisereis.com/download/ramsden-pufa-meta-analysis-chd.pdf)
Christopher E. Ramsden et al
Randomised controlled trials (RCT) of mixed n-6 and n-3 PUFA diets, and meta-analyses of their CHD outcomes, have been considered decisive
evidence in specifically advising consumption of ‘at least 5–10% of energy as n-6 PUFA’.
Here we (1) performed an extensive literature search and extracted detailed dietary and outcome data enabling a critical examination of all RCT that increased PUFA and reported relevant CHD outcomes; (2) determined if dietary interventions increased n-6 PUFA with specificity, or increased both n-3 and n-6 PUFA (i.e. mixed n-3/n-6 PUFA diets); (3) compared mixed n-3/n-6 PUFA to n-6 specific PUFA diets on relevant CHD outcomes in meta-analyses; (4) evaluated the potential confounding role of trans-fatty acids (TFA).
n-3 PUFA intakes were increased substantially in four of eight datasets, and the n-6 PUFA linoleic acid was raised with specificity in four datasets. n-3 and n-6 PUFA replaced a combination of TFA and SFA in all eight datasets. For non-fatal myocardial infarction (MI) þ CHD death, the pooled risk reduction for mixed n-3/n-6 PUFA diets was 22% (risk ratio (RR) 0·78; 95% CI 0·65, 0·93) compared to an increased risk of 13% for n-6 specific PUFA diets (RR 1·13; 95% CI 0·84, 1·53).
Risk of non-fatal MI þ CHD death was significantly higher in n-6 specific PUFA diets compared to mixed n-3/n-6 PUFA diets (P¼0·02). RCT that substituted n-6 PUFA for TFA and SFA without simultaneously increasing n-3 PUFA produced an increase in risk of death that approached statistical significance (RR 1·16; 95% CI 0·95, 1·42).
Advice to specifically increase n-6 PUFA intake, based on mixed n-3/n-6 RCT data, is unlikely to provide the intended benefits, and may actually increase the risks of CHD and death.
Full Text: Christopher E. Ramsden, Joseph R. Hibbeln, Sharon F. Majchrzak and John M. Davis (2010). <i>n</i>-6 Fatty acid-specific and mixed polyunsaturate dietary interventions have different effects on CHD risk: a meta-analysis of randomised controlled trials. British Journal of Nutrition, 104, pp 1586-1600 doi:10.1017/S0007114510004010 (http://www.canibaisereis.com/download/ramsden-pufa-meta-analysis-chd.pdf)