Olive Oil Polyphenols and Cardiovascular Health Biomarkers
- Conditions
- OverweightNormal WeightObeseHealthy
- Interventions
- Dietary Supplement: Low-polyphenol olive oilDietary Supplement: High-polyphenol olive oil
- Registration Number
- NCT04149288
- Lead Sponsor
- University of California, Davis
- Brief Summary
The purpose of this research is to investigate whether consuming two different kinds of olive oil will change risk factors related to cardiovascular disease, including levels of good and bad cholesterol, levels of inflammation, and levels of gene expression.
- Detailed Description
The purpose of this research is to investigate whether consuming two different kinds of olive oil will change risk factors related to cardiovascular disease, including levels of good and bad cholesterol, levels of inflammation, and levels of gene expression. Healthy individuals aged 20-45 with a BMI over 20 kg/m2 are eligible to participate. The study involves 5 visits (1 initial screening and 4 study visits) and will last about 8 weeks. There is a 2-week run-in period before starting the study, followed by two diet intervention periods each lasting two weeks, separated by a two-week washout period.
Participation in this study will involve an initial two-week run in period to become accustomed to the study diet. After this two week period, participants will be randomly selected to start either a high-polyphenol olive oil (extra virgin olive oil) or a low-polyphenol olive oil (refined olive oil); participants will consume the other oil during the second dietary intervention period lasting 2 weeks. During each phase of the study, participants will be asked to come to the University of California, Davis campus after a 10-12 hour overnight fast. At each visit, body measurements will be taken, a serving of olive oil and bread will be eaten, and three urine and blood samples will be collected over the course of 4 hours. Each study visit will involve three blood draws by a trained nurse or phlebotomist.
During the 8 weeks of the study, all olive products such as olives, olive oil, and olive containing products will need to be avoided. The study will provide olive oil to be eaten at home for each intervention phase. Additionally, the investigators will ask that nuts and high-polyphenol foods (mostly fruits and vegetables) be avoided in the diet. Detailed food diaries will be filled out and brought to study visits.
Recruitment & Eligibility
- Status
- ACTIVE_NOT_RECRUITING
- Sex
- All
- Target Recruitment
- 44
- Generally healthy male and female subjects within the range of 20-45 years of age and BMI range of 18.5-29.9 kg/m2 for the healthy weight/overweight group and ≥ 30 kg/m2 for the obese group will be recruited.
- Adults unable to consent, individuals who are not yet adults (infants, children, teenagers), pregnant or lactating women, women planning to become pregnant in the next two months and prisoners will be specifically excluded
- Documented chronic diseases including diabetes, thyroid disease, kidney disease, metabolic syndrome, active cancer, previous cardiovascular events, history of gastric bypass or other GI issues related to fat absorption
- History of dyslipidemia or abnormal blood glucose levels (total cholesterol >240 mg/dL, elevated fasting blood glucose levels >125 mg/dL)
- Allergy to olives, inability to tolerate gluten or multiple allergies/intolerances that would significantly limit food intake
- Smoker or living with a smoker, illicit drug use, consuming >1 alcoholic drink/day, vaporizer and/or electronic cigarette use
- Extreme dietary or exercise patterns
- Recent weight fluctuations (>10% in the last 6 months)
- Taking prescription lipid medications or supplements that may affect lipoprotein metabolism, >1 g of fish oil/day, antioxidant supplements, cannabidiol (CBD) oil
- Taking exogenous hormones (e.g. hormonal birth control)
- Poor venous access
- Unwillingness to comply with study protocol
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Arm && Interventions
Group Intervention Description Low-polyphenol olive oil Low-polyphenol olive oil Participants will consume 40 mL of low-polyphenol olive oil each day at home for 2 weeks. High-polyphenol olive oil High-polyphenol olive oil Participants will consume 40 mL of high-polyphenol olive oil each day at home for 2 weeks.
- Primary Outcome Measures
Name Time Method Assessing the influence of olive oil polyphenols on circulating oxidized LDL Through study completion, an average of 8 weeks Measure for changes in circulating levels of oxidized LDL in separated plasma at each study time point (baseline, 2 hour, 4 hour) using a commercially available ELISA kit; measured in units of U/L at each of the 4 study visits.
Assessing the influence of olive oil polyphenols on cholesterol efflux Through study completion, an average of 8 weeks Cholesterol efflux will be measured by assessing changes in reverse cholesterol transport rate in separated serum at each study time point (baseline, 2 hour, 4 hour) using a commercially available assay kit at each of the 4 study visits.
Assessing the influence of olive oil polyphenols on paraoxonase-1 (PON-1) activity Through study completion, an average of 8 weeks Measure for changes in PON-1 activity in separated plasma at each study time point (baseline, 2 hour, 4 hour) at each of the 4 study visits. Activity will be calculated based on linear rates of hydrolysis of phenyl acetate to phenol.
Assessing the influence of olive oil polyphenols on cholesterol ester transfer protein activity (CETP) Through study completion, an average of 8 weeks Changes in CETP activity will be measured at each study time point (baseline, 2 hour, 4 hour) in plasma at each of the 4 study visits. The isolated plasma will be co-incubated with donor and acceptor molecules using a commercially available assay kit.
Assessing the influence of olive oil polyphenols on blood lipid measurements Through study completion, an average of 8 weeks Measure for changes in the levels of HDL and LDL in separated plasma; measured in units of mg/dL. Blood will be assessed for the fasting (baseline) sample only at each of the 4 study visits.
Assessing the influence of olive oil polyphenols on peripheral blood mononuclear cells (PBMC) using ex vivo stimulation assays Through study completion, an average of 8 weeks Measurement of changes in PBMC derived cytokines as a marker of inflammation at each study time point (baseline, 2 hour, 4 hour) at each of the 4 study visits. Assessment will be based on an increase or decrease in concentration in pg/ml.
- Secondary Outcome Measures
Name Time Method Assessing the influence of olive oil polyphenols on gene expression in mirco RNA in PBMCs Through study completion, an average of 8 weeks Measure level of gene expression in micro RNA from PBMCs at each study time point (baseline, 2 hour, 4 ) at each of the 4 study visits. Assessment will be based on fold change between study arms.
Trial Locations
- Locations (1)
Ragle Human Nutrition Center
🇺🇸Davis, California, United States