Consumption of extra-virgin olive oil has beneficial effects on cardiovascular risk factors. The purpose of this study is to compare the effects of extra-virgin olive oil and refined olive oil, in adjunct to conventional medical treatment, in improving liver enzymes, plasma lipid profile and inflammatory markers in patients with cardiovascular risk factors.

A randomized placebo controlled clinical trial will be conducted in Rajaie Cardiovascular Center in Tehran, Iran. After review of the inclusion and exclusion criteria and explanation of the design of the study, written consent form will be completed. The participants are 40 eligible patients, aged 20-75 years. Intervention group will be received 25 mL/d extra-virgin olive oil and control group will be received 25 mL/d refined olive oil for 6 weeks. Fasting blood sample will be taken to measure lipid profile, liver enzymes and inflammatory markers (Interleukine-6 [IL-6] and Interleukine-10 [IL-10] and C-Reactive Protein [CRP]).

Inclusion Criteria:

1. patients with at least one of the cardiovascular risk factors (hypertension, hyperlipidemia, diabetes mellitus) candidate for angiography
2. willing to participation in the study

Exclusion Criteria:

1. Continuous consumption of any supplement with anti-inflammatory or antioxidant properties such as Omega-3, vitamin E, vitamin C and Selenium in last month
2. َChronic kidney disease stage 5
3. Any change in disease treatment plan such as change in type and dose of lipid lowering drugs or surgical operation