This study examined the effects of garlic and fish oil supplementation (alone and in combination) on serum lipids and lipoproteins in hypercholesterolemic subjects. The main purpose was to assess the potential for garlic supplementation, when given in combination with a fish body oil concentrate, to provide a nutritional regimen for simultaneously controlling elevated total cholesterol, LDL- cholesterol, and triglyceride levels. Also it was of interest to determine if garlic could offset the fish oil-induced rise in LDL-cholesterol which has been commonly observed.

After an initial run-in phase, 50 male subjects with moderate hypercholesterolemia were randomized for 12 weeks to one of 4 groups; (1) a control (full placebo) group consisting of garlic placebo (GP), 900 mg/d, plus vegetable oil placebo (OP), 12 g/d (GP/OP), (2) garlic (G), 900 mg/d (Kwai m), plus OP, 12 g/d (G/OP); (3) GP, 900 mg/d, plus fish oil (FO), 12 g/d (G/FO). Lipid/lipoprotein measurements on fasting samples were performed at 0, 3, 6, 9 and 12 weeks as were blood pressures. Mean total serum cholesterol level at entry was 252 mg/dl (6.55 mmol/L) whereas LDL- cholesterol was 170 mg/dl (4.42 mmol/L).

In the control group (GP/OP), mean serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and fasting triglycerides (TG) were not significantly changed in relation to baseline. Mean group TC levels were significantly lower by 12 weeks with G/OP (-11.5%, p<.001) and with G/FO (- 12.2% or -31 mg/dl, p<.001) when compared with control. In the group taking GP/FO, mean group TC levels were not significantly changed. Mean group LDL-C levels were reduced with G/OP (-14.2%,p<001) when compared with control. In the group taking fish oil (GP/FO), mean LDL-C levels were significantly raised (+8.5%,p<.005) whereas the presence of garlic (G/FO group) provided a reduction (-9.5%,p<0.01). Mean group TG levels were reduced with G/FO (- 34.3%,p<.001) and by GP/FO (-37.3%, p<.001) when compared to control. In the group taking G/OP, mean group TG levels were not significantly changed. Mean group serum high-density lipoprotein cholesterol (HDL-C) levels were not significantly elevated under any treatment when compared to the controls although garlic alone (G/OP) and garlic plus fish oil (G/FO) provided significantly lower rates of TC/HDL-C. Mean blood pressure decreased by 2.4% in all but the control (full placebo) group. Food records indicated no significant differences in macro-nutrient dietary intakes across the groups. Compliance was monitored by supplement counts and fatty acid analyses of omega-3 fatty acids in serum phospholipid.

Garlic supplementation alone (G/OP) significantly decreased both TC and LDL-C levels while fish oil supplementation alone (GP/FO) significantly decreased TG levels and increased LDL-C levels. The combination of garlic plus fish oil (G/FO) prevented the moderate fish oil-induced rise in LDL-C and gave an overall decrease. Co-administration of garlic and fish oil for 12 weeks was generally well- tolerated over the experimental period and exhibited a beneficial effect on serum lipid and lipoprotein levels by providing a combined lowering of TC, LDL-C, and TG levels as well as a lowering of TC/HDL and LDL-C/HDL-C ratios in the hypercholesterolemic subjects.