Effects of fatty and lean fish intake on blood pressure in subjects with coronary heart disease using multiple medications

Background Intake of fish and long-chain n-3 fatty acids has been of wide interest due to their beneficial effects on cardiovascular risk factors and lower coronary heart disease (CHD) risk. Aim of the study The aim of this pilot study was to examine the effects of fatty fish and lean (white) fish on fatty acid composition of serum lipids and cardiovascular risk factors in subjects with CHD using multiple drugs for this condition. Methods The study was an 8-week controlled, parallel intervention. Inclusion criteria were myocardial infarction or unstable ischemic attack, age under 70 years, use of betablockers and presence of sinus rhythm. The subjects were randomized to one of the following groups: 4 meals/week fatty fish (n = 11), 4 meals/week lean fish (n = 12) and control diet including lean meat (n = 10). Results The mean (+/- SD) of reported fish meals per week was 4.3 +/- 0.4, 4.7 +/- 1.1 and 0.6 +/- 0.4 in the groups, respectively. The proportions of eicosapentaenoic and docosahexaenoic acids in serum lipids increased in the fatty fish group only (P < 0.05). Systolic and diastolic blood pressure levels decreased in the lean fish group (0 vs. 8 week: 3.5 +/- 3.2 and 4.6 +/- 3.6%, respectively, P < 0.05). Serum total triglyceride concentration did not significantly change. HDL cholesterol concentration change differed among groups but without significant post hoc differences. Apolipoprotein A-1 concentration decreased in the control group (0 vs. 8 week, P < 0.05). Coagulation factors, 25-hydroxy vitamin D, and heart rate variability (24 h Holter) did not change among the groups. Conclusions Our results suggest that intake of lean fish at least four times per week could reduce blood pressure levels in CHD patients.