Canola oil decreases cholesterol and improves endothelial function in patients with peripheral arterial occlusive disease – a pilot study☆

Summary 

Background

Dietary supplementation with omega-3 PUFAs has been shown to reduce cardiovascular morbidity and mortality. This pilot study investigated the effects of supplementation with plant-derived omega-3 and omega-6 PUFAs in patients with atherosclerosis.

Methods

Forty patients with PAD supplemented their usual diet with 2 tablespoons/day of canola oil (n=20) or sunflower oil (n=20), containing 2.24g of α-linolenic acid or 16.24g of linoleic acid, respectively, for 8weeks. Laser Doppler flux (LDF), was assessed at rest and during reactive hyperaemia. Other measurements included parameters of heart rate variability (HRV), markers of plasmatic coagulation, fibrinolysis, platelet activation, inflammation, and lipid and homocysteine levels.

Results

Despite randomization, baseline values for LDF and HRV differed between the two groups. LDL-cholesterol decreased (from 2.74±0.73 to 2.42±0.65mmol/L, p=0.007) with canola oil but not with sunflower oil. The difference in the percent increase of LDF after ischemic challenge increased with canola oil from a median (25th; 75th percentiles) of 75.2% (48.6; 161.2) to 151.7% (117.8; 260.0) (p=0.008) and with sunflower oil from 157.9% (125.4; 229.8) to 178.6% (127.3; 356.3) (p=0.03), whereas a control group did show no change. HRV and other markers did not change.

Conclusions

Canola oil containing omega-3 PUFAs may confer cardiovascular protection by improving endothelial function and lowering LDL-cholesterol, but additional studies are warranted.

Keywords: Peripheral arterial occlusive disease, Atherosclerosis, Polyunsaturated fatty acids, Endothelial function, Canola oil

Abbreviations: %RR50, the percent difference between adjacent RR intervals that were greater than 50msec, ALA, α-linolenic acid, DHA, docosapentaneoic acid, DD, D-dimers, EPA, eicosapentaneoic acid, F1+2, prothrombin fragment 1+2, FMD, flow-mediated dilation, GISSI, gruppo italiano per lo studio della sopravvivenza nell'infarto miocardio, LA, linoleic acid, LDF, laser Doppler flow, NO, nitric oxide, PAD, peripheral artery occlusive disease, PAI-1, plasminogen activator inhibitor-1, PUFA, polyunsaturated fatty acid, rmsSD, the square root of the mean of the sum of the squares of differences between adjacent RR intervals, SDANN, the standard deviation of the normal RR intervals averaged over 5min intervals during the monitoring period, SDNN, the standard deviation of all normal RR intervals observed over the monitoring period, TAT, thombin-antithrombin complex, t-PA, tissue-type plasminogen activator