Savannah Environmental Nutrition Study (SENS): Nutrition Intervention to Reduce Air Pollution-Related Airway Inflammation and Oxidative Stress

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.

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