Air Pollution Exposure, Airway Inflammation, Oxidative Stress
Conditions
Keywords
Air pollution, Nutrition intervention, Oxidative stress, Exhaled nitric oxide, FeNO, Exhaled breath condensate, Hydrogen peroxide, Particulate matter, Nitrogen dioxide, Ozone, Cardiometabolic health
Brief summary
This pilot clinical trial will evaluate the feasibility and potential health effects of a nutrition-based intervention among adults living in communities affected by air pollution near the Port of Savannah, Georgia. Participants will be assigned to either a nutrition intervention group or a control group. The intervention group will receive biweekly grocery deliveries emphasizing foods naturally rich in antioxidants and anti-inflammatory nutrients, including vitamins C and E, omega-3 fatty acids, and polyphenols. The control group will continue their usual dietary practices during the study period. The study will evaluate whether the nutritional intervention is associated with changes in selected respiratory, oxidative stress, and cardiometabolic health indicators. Assessments will include fractional exhaled nitric oxide (FeNO) as a marker of airway inflammation, hydrogen peroxide (H₂O₂) in exhaled breath condensate as a marker of oxidative stress, systolic and diastolic blood pressure, resting heart rate, and glycated hemoglobin (HbA1c). Indoor concentrations of particulate matter (PM), nitrogen dioxide (NO₂), and ozone (O₃) will also be monitored to characterize participants' household air-pollution exposures. Measurements will be collected at baseline and at subsequent study assessments, as specified for each outcome. Findings from this pilot study will be used to evaluate feasibility, estimate changes in health outcomes, and inform the design of a larger clinical trial investigating nutritional approaches to potentially reduce health effects associated with air-pollution exposure.
Detailed description
Exposure to air pollution is associated with oxidative stress and inflammatory responses that may contribute to adverse respiratory and cardiovascular health effects. Nutritional factors may influence antioxidant defenses and inflammatory pathways; however, relatively little intervention research has examined whether improving dietary intake can modify biological responses among individuals experiencing ongoing environmental air-pollution exposures. This pilot clinical trial will investigate the feasibility and potential effects of a food-based nutritional intervention among adults residing in communities affected by air pollution near the Port of Savannah, Georgia. The study will include 20 participants, who will be assigned to a nutrition intervention group or a control group according to the study's approved allocation procedure. Participants in the intervention group will receive biweekly grocery deliveries emphasizing foods naturally rich in antioxidant and anti-inflammatory dietary components, including vitamins C and E, omega-3 fatty acids, and polyphenols. Participants assigned to the control group will maintain their usual dietary practices during the active study period. Intervention feasibility and adherence will also be evaluated to inform the design and implementation of a future larger-scale trial. Respiratory and oxidative-stress assessments will include fractional exhaled nitric oxide (FeNO), measured using a NIOX Mini device, and hydrogen peroxide (H₂O₂) measured in exhaled breath condensate collected using an RTube® collection system. Cardiometabolic assessments will include systolic and diastolic blood pressure and resting heart rate measured using a validated automatic upper-arm blood pressure monitor. HbA1c will be assessed at baseline and the final assessment as an exploratory measure of longer-term glycemic status. Indoor particulate matter (PM), nitrogen dioxide (NO₂), and ozone (O₃) will also be monitored to characterize household air-pollution exposures. Study assessments will be performed at baseline and at subsequent study time points according to the protocol. Changes in respiratory, oxidative-stress, and cardiometabolic measures will be compared over time and between study groups. Because this is a pilot study, the findings will primarily be used to evaluate study feasibility, intervention adherence, outcome variability, and preliminary effect estimates rather than to establish definitive clinical efficacy. The results will provide information needed to refine the intervention, outcome-selection strategy, and study procedures and to estimate parameters needed for the design of a larger clinical trial.
Interventions
OTHERAntioxidant- and Nutrient-Rich Food-Based Nutrition Intervention
Participants assigned to the intervention will receive biweekly grocery deliveries containing selected foods naturally rich in antioxidant and anti-inflammatory dietary components, including vitamins C and E, omega-3 fatty acids, and polyphenols. Participants will receive guidance on incorporating the provided foods into their usual dietary patterns. The intervention is designed to increase consumption of nutrient-rich foods and to evaluate the feasibility and potential effects of this dietary approach on respiratory inflammation, oxidative stress, and cardiometabolic outcomes among adults living in a community affected by air pollution.
Sponsors
Georgia Southern University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Intervention model description
Participants will be randomly assigned to one of two parallel study groups: a nutrition intervention group or a control group. Participants in the intervention group will receive biweekly grocery deliveries emphasizing foods naturally rich in antioxidant and anti-inflammatory dietary components, including vitamins C and E, omega-3 fatty acids, and polyphenols. Participants in the control group will maintain their usual dietary practices during the active study period. Respiratory, oxidative-stress, cardiometabolic, and environmental exposure measures will be assessed according to the study protocol and compared between groups and over time.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Residing in Port Wentworth or the Savannah main Channel at a 3-mile radius for the prior 12 months and not planning to move during the study. * Non-smoking status (or specified ANY smoking history) * Absence of pre-existing chronic respiratory conditions (Asthma, Chronic Obstructive Pulmonary Disease, Seasonal respiratory allergies that require the use of antihistamines or immunosuppressants more than once a month, Chronic Bronchitis, and Heart Failure or any condition that would put participants at a greater risk than other participants for a pre-existing condition. * Willingness and ability to participate in home monitoring protocols * Willingness to receive and use grocery delivery for the nutrition intervention * Willingness and ability to follow the study procedures * Own a refrigerator * Allow investigators to do 1.5 hour home visits, and several calls and texts * Having a kitchen and the ability to prepare, cook meals, and eat them at home * Living in a household with 4 or fewer people
Exclusion criteria
* Individuals unable to follow study procedures * Antihistamines or any immunosuppressors, ongoing cancer treatment or within the past 5 years * Individuals unable to read, speak, and/or understand English or Spanish * Any food allergy * Strong dislike to most vegetables or fruits * Having ever been diagnosed with an eating disorder or autoimmune disorder * Being currently treated for any type of cancer * Households with 5 or more people living in the same space
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Participant Retention Rate | Baseline through Week 12. | Through the Final Assessment Participant retention will be assessed as the proportion of enrolled participants who complete the study through the final Week 12 assessment. Retention rate will be calculated as the number of enrolled participants who complete the final assessment, divided by the total number of participants enrolled at baseline, multiplied by 100. A retention rate of ≥80% will be considered evidence of acceptable feasibility for a future larger-scale trial. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change From Baseline in Fractional Exhaled Nitric Oxide (FeNO) | Baseline, approximately Week 6, and Week 12 | Fractional exhaled nitric oxide (FeNO) will be measured in parts per billion (ppb) using the NIOX Mini device as a non-invasive marker of airway inflammation. FeNO will be assessed using standardized procedures, and changes over time will be compared between the nutrition intervention and control groups. |
| Change From Baseline in Hydrogen Peroxide (H₂O₂) Concentration in Exhaled Breath Condensate | Baseline, approximately Week 6, and Week 12 | Hydrogen peroxide (H₂O₂) concentration in exhaled breath condensate (EBC) will be measured as a non-invasive marker of respiratory oxidative stress. EBC will be collected using the RTube® collection system, and H₂O₂ concentration will be quantified using the Amplex™ Red Hydrogen Peroxide/Peroxidase Assay with fluorescence detection. H₂O₂ concentrations will be reported in micromolar (µM) units. Changes from baseline will be evaluated over the intervention period and compared between the nutrition intervention and control groups. |
| Change From Baseline in Systolic Blood Pressure | Baseline, approximately Week 6, and Week 12 | Systolic blood pressure will be measured in millimeters of mercury (mmHg) using a validated automatic upper-arm blood pressure monitor. Participants will obtain two measurements approximately one minute apart after at least five minutes of seated rest, and the average of the two measurements will be used for analysis. |
| Change From Baseline in Diastolic Blood Pressure | Baseline, approximately Week 6, and Week 12 | Diastolic blood pressure will be measured in millimeters of mercury (mmHg) using a validated automatic upper-arm blood pressure monitor. Two measurements approximately one minute apart will be obtained after at least five minutes of seated rest, and the average will be used for analysis. |
| Change From Baseline in Resting Heart Rate | Baseline, approximately Week 6, and Week 12 | Resting heart rate will be measured in beats per minute (bpm) using a validated automatic upper-arm blood pressure monitor after the participant has rested quietly in a seated position for at least five minutes. Two resting heart rate measurements will be obtained approximately one minute apart, and the mean of the two measurements will be used as the resting heart rate value for each assessment. |
| Change From Baseline in Glycated Hemoglobin (HbA1c) | Baseline and Week 12 | Glycated hemoglobin (HbA1c) will be measured using an FDA-cleared point-of-care finger-stick testing system as an exploratory marker of longer-term glycemic status. HbA1c will be reported as a percentage. |
| Recruitment/Accrual Rate | From initiation of recruitment through completion of study enrollment, approximately 6 months. | Recruitment rate will be assessed as the proportion of individuals determined to be eligible for the study who enroll and complete the baseline assessment. The recruitment rate will be calculated as the number of eligible individuals enrolled divided by the total number of eligible individuals approached/invited to participate, multiplied by 100. Recruitment feasibility will be evaluated against a prespecified target of ≥70% enrollment of eligible individuals. |
| Adherence to the Food-Based Nutrition Intervention | Throughout the 12-week intervention. | Intervention adherence and fidelity will be evaluated among participants assigned to the nutrition intervention group. Delivery fidelity will be assessed as the proportion of scheduled biweekly grocery deliveries successfully completed during the 12-week intervention. Participant adherence will be assessed using study records and participant-reported consumption of the targeted foods provided through the intervention. These measures will be used to determine whether the food-based nutrition intervention can be delivered as planned and followed by participants in preparation for a future larger-scale clinical trial. |
Countries
United States
Contacts
CONTACTAtin Adhikari, PhD
Outcome results
None listed