Dietary lipids and blood cholesterol: quantitative meta-analysis of metabolic ward studies.
OBJECTIVE
To determine the quantitative importance of dietary fatty acids and dietary cholesterol to blood concentrations of total, low density lipoprotein, and high density lipoprotein cholesterol.


METHODS
Meta-analysis of metabolic ward studies of solid food diets in healthy volunteers.


METHODS
395 dietary experiments (median duration 1 month) among 129 groups of individuals.


RESULTS
Isocaloric replacement of saturated fats by complex carbohydrates for 10% of dietary calories resulted in blood total cholesterol falling by 0.52 (SE 0.03) mmol/l and low density lipoprotein cholesterol falling by 0.36 (0.05) mmol/l. Isocaloric replacement of complex carbohydrates by polyunsaturated fats for 5% of dietary calories resulted in total cholesterol falling by a further 0.13 (0.02) mmol/l and low density lipoprotein cholesterol falling by 0.11 (0.02) mmol/l. Similar replacement of carbohydrates by monounsaturated fats produced no significant effect on total or low density lipoprotein cholesterol. Avoiding 200 mg/day dietary cholesterol further decreased blood total cholesterol by 0.13 (0.02) mmol/l and low density lipoprotein cholesterol by 0.10 (0.02) mmol/l.


CONCLUSIONS
In typical British diets replacing 60% of saturated fats by other fats and avoiding 60% of dietary cholesterol would reduce blood total cholesterol by about 0.8 mmol/l (that is, by 10-15%), with four fifths of this reduction being in low density lipoprotein cholesterol.
Clarke
R
R
Clinical Trial Service Unit, Radcliffe Infirmary, Oxford.
Frost
C
C
Collins
R
R
Appleby
P
P
Peto
R
R
D002791:Cholesterol, Dietary / Q000378:metabolism*; D008076:Cholesterol, HDL / Q000097:blood*; D018592:Cross-Over Studies; D004032:Diet; D004041:Dietary Fats / Q000378:metabolism*; D002149:Energy Intake; D006801:Humans; D008077:Lipoproteins, LDL / Q000097:blood*; D015999:Multivariate Analysis; D016032:Randomized Controlled Trials as Topic
D002791:Cholesterol, Dietary; D008076:Cholesterol, HDL; D004041:Dietary Fats; D008077:Lipoproteins, LDL