Abstract
Does trans-fatty acid intake affect blood cholesterol?
Food health relationship Increased trans-fatty acid intake increases LDL cholesterol and reduces HDL cholesterol
Proposed GRADE rating High
Component Notes
Body of evidence A 2010 systematic review and meta-analysis of randomised controlled trials was updated to include 11 relevant studies up to March 2014. The findings are generally consistent with the previous evidence.
Consistency The updated results of the meta-analysis showed small but significant increases in LDL cholesterol and decreases in HDL cholesterol when cis mono-unsaturated fat is replaced with trans fat on an isoenergy basis. Sensitivity analyses did not change the direction of these effects.
Causality Randomised controlled trials provide a strong study design for causal evidence. Substantial clustering around low intakes limited the ability of this review to assess potential threshold, dose response or nonlinear relationships. In addition, some studies used high intakes not realistically attainable within a normal diet.
Plausibility The mechanisms whereby trans-fatty acids contribute to changes in blood lipid profiles remain uncertain. Several potential mechanisms exist, including increased plasma activity of cholesteryl ester transfer protein enzyme which has been proposed to be the driver of decreased HDL and increased LDL cholesterol levels.
Generalisability There appears to be little risk associated with the low level of trans-fatty acid intakes reported in Australia and New Zealand in 2009. Populations covered by reviewed studies covered a wide range of ages and included both healthy and hyperlipidemic subjects, although results cannot be generalised to children or people who are acutely ill.
Food health relationship Increased trans-fatty acid intake increases LDL cholesterol and reduces HDL cholesterol
Proposed GRADE rating High
Component Notes
Body of evidence A 2010 systematic review and meta-analysis of randomised controlled trials was updated to include 11 relevant studies up to March 2014. The findings are generally consistent with the previous evidence.
Consistency The updated results of the meta-analysis showed small but significant increases in LDL cholesterol and decreases in HDL cholesterol when cis mono-unsaturated fat is replaced with trans fat on an isoenergy basis. Sensitivity analyses did not change the direction of these effects.
Causality Randomised controlled trials provide a strong study design for causal evidence. Substantial clustering around low intakes limited the ability of this review to assess potential threshold, dose response or nonlinear relationships. In addition, some studies used high intakes not realistically attainable within a normal diet.
Plausibility The mechanisms whereby trans-fatty acids contribute to changes in blood lipid profiles remain uncertain. Several potential mechanisms exist, including increased plasma activity of cholesteryl ester transfer protein enzyme which has been proposed to be the driver of decreased HDL and increased LDL cholesterol levels.
Generalisability There appears to be little risk associated with the low level of trans-fatty acid intakes reported in Australia and New Zealand in 2009. Populations covered by reviewed studies covered a wide range of ages and included both healthy and hyperlipidemic subjects, although results cannot be generalised to children or people who are acutely ill.
Original language | English |
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Publisher | Food Standards Australia New Zealand |
Commissioning body | Food Standards Australia New Zealand |
Number of pages | 57 |
Publication status | Published - 2014 |