The effects of canola and olive oils on insulin resistance, inflammation and oxidative stress in women with type 2 diabetes: a randomized and controlled trial.

BACKGROUND

A number of studies have shown that consumption of vegetable oils may improve diabetes complications including inflammatory response and oxidative stress, but no study has been done on the effects of canola oil (CO) and olive oil (OO) consumption in patients with type 2 diabetes. This clinical trial was done to compare the effects of CO and OO on insulin resistance, inflammation and oxidative stress in women with type 2 diabetes.

METHODS

This randomized controlled clinical trial was done on 77 type 2 diabetic women. 4 weeks before the intervention, lipid-lowering drugs intakes were cut under the supervision of an endocrinologist. The participants were randomly divided into 2 intervention groups (Balanced diet +30 g/day CO or OO) and one control group (Balanced diet +30 g/day of sunflower oil (SFO)). Dietary intakes were assessed using three 24-h food records at baseline and at weeks 4 and 8 of the interventions. At baseline and after 8 weeks, height, weight, waist circumference, fasting blood sugar (FBS), serum insulin, C-reactive protein (CRP) and malondialdehyde (MDA) were measured.

RESULTS

After the intervention in the inter-group analysis, CRP level was reduced significantly in CO and OO groups but no significant changes were observed in other factors. CRP reductions were also significant between all of the groups but not for other factors.

CONCLUSIONS

Replacing CO and OO with SFO as part of daily dietary fat in the diet of people with type 2 diabetes is recommended for reducing Inflammation and Oxidative Stress. This study is approved by the Ethics Committee of Shiraz University of Medical Sciences (IR.SUMS.REC.1394.27) and is recorded in the Iranian Registry of Clinical Trials (IRCT2015062722818N1).