Effects of dietary saturated, monounsaturated, and n-3 fatty acids on blood pressure in healthy subjects.
BACKGROUND
The quantity and quality of fats consumed in the diet influence the risk of cardiovascular disease (CVD). Although the effect of diet on plasma lipids and lipoproteins is well documented, less information exists on the role of fats on blood pressure (BP).


OBJECTIVE
The objective was to evaluate the effects of different types of dietary fat on BP in healthy subjects.


METHODS
Healthy subjects (n = 162) were randomly assigned for 3 mo to follow 1 of 2 isoenergetic diets: 1 rich in monounsaturated fatty acids (MUFA diet) and the other rich in saturated fatty acids (SFA diet). Each group was further randomly assigned to receive supplementation with fish oil (3.6 g n-3 fatty acids/d) or placebo.


RESULTS
Systolic BP (SBP) and diastolic BP (DBP) decreased with the MUFA diet [-2.2% (P = 0.009) and -3.8% (P = 0.0001), respectively] but did not change with the SFA diet [-1.0% (P = 0.2084) and -1.1% (P = 0.2116)]. The MUFA diet caused a significantly lower DBP than did the SFA diet (P = 0.0475). Interestingly, the favorable effects of MUFA on DBP disappeared at a total fat intake above the median (>37% of energy). The addition of n-3 fatty acids influenced neither SBP nor DBP.


CONCLUSIONS
Changing the proportions of dietary fat by decreasing SFAs and increasing MUFAs decreased diastolic BP. Interestingly, the beneficial effect on BP induced by fat quality was negated by the consumption of a high total fat intake. The addition of n-3 fatty acids to the diet had no significant effect on BP.
Rasmussen
Birthe M
BM
Department of Clinical Endocrinology and Metabolism C, Aarhus University Hospital, Aarhus, Denmark.
Vessby
Bengt
B
Uusitupa
Matti
M
Berglund
Lars
L
Pedersen
Eva
E
Riccardi
Gabrielle
G
Rivellese
Angela A
AA
Tapsell
Linda
L
Hermansen
Kjeld
K
D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D004041:Dietary Fats / Q000008:administration & dosage*; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage; D002149:Energy Intake / Q000502:physiology; D005227:Fatty Acids / Q000008:administration & dosage*; D005229:Fatty Acids, Monounsaturated / Q000008:administration & dosage*; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D005260:Female; D005395:Fish Oils; D006801:Humans; D008297:Male; D008875:Middle Aged
D004041:Dietary Fats; D004042:Dietary Fats, Unsaturated; D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D015525:Fatty Acids, Omega-3; D005395:Fish Oils