Efficacy of Fish Oil or Olive Oil Supplementation on the Health Effects of Ozone Exposure in Healthy Young Subjects (OMEGOZ)
![]() |
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. |
ClinicalTrials.gov Identifier: NCT03395119 |
Recruitment Status :
Completed
First Posted : January 10, 2018
Last Update Posted : January 15, 2021
|
- Study Details
- Tabular View
- No Results Posted
- Disclaimer
- How to Read a Study Record
Purpose: A growing body of epidemiological data suggests an increased risk of cardiovascular events associated with air pollution. One of the common air pollutants, ozone, has been shown to induce oxidative stress and inflammation in the cardiovascular and respiratory systems. This proposed study is to examine the efficacy of fish oil and olive oil in modulating cardiovascular and pulmonary functions after ozone exposure. The objective is to understand the mechanistic basis for the health effects of ozone relative to those air pollutants. Treatment groups will include forty healthy young adults who will be given dietary supplementation of fish oil or olive oil. A control group will consist of 20 healthy volunteers who will receive no supplements. After 4 weeks, subjects will be exposed to clean air for 2 hours on the first day, then ozone for 2 hours on the second day. Cardiac rhythm, pulmonary function, vascular responses, endothelial function, and markers of coagulation and airway inflammation pre- and post- ozone exposure will be measured. This study is designed to build on the previous nutritional supplement interventional studies (UNC IRB # 07-0190 and UNC IRB # 11-1807), in order to understand the mechanism of action of particulate pollutants in comparison to that of ozone, a known oxidant air contaminant.
Participants: A total of sixty healthy 18-35 year-old male and female subjects will be involved in the study.
Procedures (methods): Forty healthy young adults will receive dietary supplementation consisting of fish oil or olive oil for 4 weeks. The control group includes 20 healthy volunteers who will receive no supplements in the study. After 4 weeks of supplementation or control regiment, each subject will be exposed to clean air for 2 hours on the first day, then ozone for 2 hours on the second day.
Condition or disease | Intervention/treatment | Phase |
---|---|---|
Healthy Dietary Supplement | Drug: Ozone Dietary Supplement: Fish Oil Dietary Supplement: Olive Oil | Phase 1 |

Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 44 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Double (Participant, Investigator) |
Masking Description: | Both participant and investigators are blinded for the assignment of dietary supplementation of fish oil, olive oil or control. |
Primary Purpose: | Basic Science |
Official Title: | Efficacy of Fish Oil or Olive Oil Supplementation on the Health Effects of Ozone Exposure in Healthy Young Subjects |
Actual Study Start Date : | December 18, 2017 |
Actual Primary Completion Date : | December 18, 2020 |
Actual Study Completion Date : | December 18, 2020 |

Arm | Intervention/treatment |
---|---|
Sham Comparator: No Supplements
The control group includes 20 healthy volunteers who will receive no supplements in the study. After 4 weeks, subjects will be exposed to clean air for 2 hours on the first day, then ozone for 2 hours on the second day
|
Drug: Ozone
After the four-week supplementation period, each subject will be blindly exposed on consecutive days to filtered air for 2 hours and to 0.3 ppm ozone for 2 hours, while undergoing intermittent moderate exercise (minute ventilation of 20 L/min/m²).
Other Name: Filtered air |
Experimental: Fish oil
Twenty healthy young adults will receive fish oil supplements for 4 weeks. After 4 weeks, subjects will be exposed to clean air for 2 hours on the first day, then ozone for 2 hours on the second day
|
Drug: Ozone
After the four-week supplementation period, each subject will be blindly exposed on consecutive days to filtered air for 2 hours and to 0.3 ppm ozone for 2 hours, while undergoing intermittent moderate exercise (minute ventilation of 20 L/min/m²).
Other Name: Filtered air Dietary Supplement: Fish Oil 3 (1-gram) soft-gels daily Commercially available, enteric-coated, soft-gels formulated to deliver >60% eicosapentaenoic/docosahexaenoic acids (EPA/DHA)
Other Name: omega-3 fatty acids (eicosapentaenoic/docosahexaenoic) |
Experimental: Olive oil
Twenty healthy young adults will receive olive oil supplements for 4 weeks. After 4 weeks, subjects will be exposed to clean air for 2 hours on the first day, then ozone for 2 hours on the second day
|
Drug: Ozone
After the four-week supplementation period, each subject will be blindly exposed on consecutive days to filtered air for 2 hours and to 0.3 ppm ozone for 2 hours, while undergoing intermittent moderate exercise (minute ventilation of 20 L/min/m²).
Other Name: Filtered air Dietary Supplement: Olive Oil 3 soft-gels daily Commercially available soft-gels containing 1 gram of USDA organic certified, cold pressed, extra virgin, olive oil
Other Name: extra virgin olive oil |
- Change in forced expired volume in the first second (FEV1) from air exposure (Day 1) to ozone exposure (Day 2) [ Time Frame: Day 1, Day 2 ]FEV1 is determined by spirometry
- endothelial cell function 1 hour post-exposure [ Time Frame: 1 hour pre-exposure, 1 hour post-exposure ]Brachial artery ultrasound will be used to evaluate flow-mediated dilatation which will be performed in the Human Studies Facility (HSF) at U.S. Environmental Protection Agency (EPA) using an ultrasound instrument. The diameter of the brachial artery will be measured at baseline and during reactive hyperemia.
- endothelial cell function 18 hour post-exposure [ Time Frame: 1 hour pre-exposure, 18 hour post-exposure ]Brachial artery ultrasound will be used to evaluate flow-mediated dilatation which will be performed in the HSF at EPA using an ultrasound instrument. The diameter of the brachial artery will be measured at baseline and during reactive hyperemia.
- diameters of retinal arteries and veins 1 hour post-exposure [ Time Frame: 30 min pre-exposure, 1 hour post-exposure ]Retinal images will be taken using an FDA-approved, commercially available, non-mydriatic fundus camera. Images will be taken from both eyes.
- diameters of retinal arteries and veins 18 hour post-exposure [ Time Frame: 30 min pre-exposure, 18 hour post-exposure ]Retinal images will be taken using an FDA-approved, commercially available, non-mydriatic fundus camera. Images will be taken from both eyes.
- airway inflammation 4 hour post-exposure [ Time Frame: 6 weeks prior to the exposure, 4 hour post-exposure ]Sputum induction will be performed to determine the airway inflammation.
- Heart rate variability 1 hour post-exposure [ Time Frame: 1 hour pre-exposure, 1 hour post-exposure ]Heart rate variability will be collected by the Holter monitor.
- Heart rate variability 18 hour post-exposure [ Time Frame: 1 hour pre-exposure, 18 hour post-exposure ]Heart rate variability will be collected by the Holter monitor.
- Blood fatty acids 2 hour post-exposure [ Time Frame: 6 weeks prior to the exposure, 2 hours pre-exposure ]Blood sample will be collected for fatty acids analysis
- Blood fatty acids 30 min post-exposure [ Time Frame: 2 hour pre-exposure, 30 min post-exposure ]Blood sample will be collected for fatty acids analysis
- Blood fatty acids 18 hour post-exposure [ Time Frame: 2-hour pre-exposure, 18 hour post-exposure ]Blood sample will be collected for fatty acids analysis
- Blood cholesterol 2 hour post-exposure [ Time Frame: 6 weeks prior to the exposure, 2 hours pre-exposure ]Blood sample will be collected for measuring the cholesterol level
- Blood cholesterol 30 min post-exposure [ Time Frame: 2 hour pre-exposure, 30 min post-exposure ]Blood sample will be collected for measuring the cholesterol level
- Blood cholesterol 18 hour post-exposure [ Time Frame: 2-hour pre-exposure, 18 hour post-exposure ]Blood sample will be collected for measuring the cholesterol level
- Forced expired volume in the first second (FEV1) 18 hour post-exposure [ Time Frame: immediate post-exposure to ozone within 30 min, 18 hour post-exposure ]Forced expired volume in the first second (FEV1) is determined by the spirometry

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 18 Years to 35 Years (Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
- Age 18-35 years old healthy male and female (19≤BMI≤30).
- Physical conditioning allowing intermittent, moderate exercise for 2 hours, and ability to complete the exposure exercise regimen chosen to induce a minute ventilation rate of 20 L/min/m² for 15 minutes without exceeding 80% of predicted maximal heart rate.
- Normal resting electrocardiography (ECG)
- Normal lung function
- Oxygen saturation greater than 94% at the time of physical exam.
- Individuals whose blood omega-3 index is 5% or lower at the time of screening.
Exclusion Criteria:
- Individuals with a history of acute or chronic cardiovascular disease, chronic respiratory disease, cancer (possible exception for history of non-melanoma skin cancer), rheumatologic disease, neuromuscular disease, or immunodeficiency state.
- Individuals with a cardiovascular disease risk score greater than 10% using the American College of Cardiology and the American Heart Association Atherosclerotic Cardiovascular Disease risk calculator. (Based on the 10-year risk of heart disease or stroke using the Atherosclerotic Cardiovascular Disease algorithm published in 2013 American College of Cardiology/American Heart Association Guideline on the Assessment of Cardiovascular risk.)
- Uncontrolled hypertension (>150 systolic, >90 diastolic).
- Individuals who are diabetic (previously diagnosed or with hemoglobin A1c level >6.4%).
- Individuals with asthma or a history of asthma.
- Individuals who are allergic to chemical vapors or gases.
- Individuals who have skin allergy to tape or electrodes.
- Individuals is pregnant, attempting to become pregnant or breastfeeding.
- Individuals who are currently smoking (including vaping, hookah and e-cigarette) or have smoking history within 1 year of study (defined as more than 1 pk/yr in the past year) or have a greater than/equal to a 5 pack year smoking history.
- Individuals living with a smoker who smokes inside the house.
- Individuals who are regularly exposed to high levels of vapors, dust, gases, or fumes.
- Individuals that do not understand or speak English.
- Individuals that are unable to perform the exercise required for the study.
- Individuals who are taking Î2-blocker medications.
- Individuals who are allergic to fish or omega-3 fatty acids, or are on prescription of taking omega-3 fish oil as therapy.
- Individuals that are unwilling or unable to stop taking medications that may impact the results of ozone challenge for the duration of the study. Medications not specifically mentioned here may be reviewed by the investigators prior to an individuals inclusion in the study.
- Individuals who are unwilling or unable to stop taking any current dietary supplements for the duration of the study. Prebiotics and probiotics are acceptable.
- Individuals who are unwilling or unable to adhere to study specific dietary restrictions (see details under A.4.2 dietary instruction).
- Individuals who have unspecified illnesses, which in the judgment of the investigators might increase the risk associated with ozone inhalation will be a basis for exclusion.
- Individuals with bleeding/clotting disorders.
- Individuals who are not willing to participate the induced sputum procedure on the training day.
Temporary exclusion criteria:
- Individuals who have recent (within 6 month) abdominal and/or eye surgery, or with any types of hernia, as well as any other contraindications for raised intra-abdominal pressure.
- Individuals who have had an acute respiratory illness within 4 weeks.
- Individuals who are currently taking systemic steroids, oral anticoagulants, over-the counter pain medications (such as aspirin, Advil, Aleve) or nonsteroidal anti-inflammatory drugs, or have taken these medications within the last 14 days.
- Individuals who have active allergies.
Use of other medications will be evaluated on a case-by-case basis. There is the potential that an individuals current medication use will preclude them from participating in the study at the current time, but they may be reassessed and potentially rescheduled for participation at a later time.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03395119
United States, North Carolina | |
U.S. Environmental Protection Agency Human Studies Facility | |
Chapel Hill, North Carolina, United States, 27514 |
Principal Investigator: | James Samet, PhD | Environmental Protection Agency, University of North Carolina at Chapel Hil |
Responsible Party: | University of North Carolina, Chapel Hill |
ClinicalTrials.gov Identifier: | NCT03395119 |
Other Study ID Numbers: |
15-2960 |
First Posted: | January 10, 2018 Key Record Dates |
Last Update Posted: | January 15, 2021 |
Last Verified: | January 2021 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | Yes |
Plan Description: | Deidentified individual data will be shared through the U.S. EPA's ScienceHub database. ScienceHub is used to upload and store datasets associated with journal articles. Non-sensitive datasets are then made publicly accessible via the Environmental Dataset Gateway in fulfillment of the EPA's requirement to adhere to the Office of Management and Budget's Open Data Policy. |
Time Frame: | Data will be available in ScienceHub after the publication of the study is completed. |
Access Criteria: | Data will be available to the public |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Ozone exposure Healthy Adults |