Evaluation of the Antioxidant and Anti-Inflammatory Capacities of the 'Rosy Red Valencia' and 'Olinda Valencia' Sweet Orange Varieties in Healthy Subjects

Not Applicable

Recruiting

• Conditions: Healthy

• Registration Number: NCT06944210
• Lead Sponsor: University of California, Davis

Brief Summary

This study aims to evaluate the antioxidant and anti-inflammatory effects of acute and chronic consumption of two sweet orange (Citrus sinensis) varieties-'Rosy Red Valencia', which is rich in carotenoids such as lycopene, phytoene, and phytofluene, and 'Olinda Valencia', which lacks these carotenoids-in healthy adults. In this 4-week, randomized, parallel-arm clinical trial, participants will consume either 'Rosy Red Valencia' or 'Olinda Valencia' oranges daily. The study will assess the effects of sweet orange intake on markers of oxidative stress and inflammation, plasma carotenoid concentrations, gene expression in peripheral blood mononuclear cells, and gut health. Findings from this study may help identify potential health benefits associated with specific carotenoid profiles in sweet oranges and provide insights into their role in modulating inflammation and oxidative stress.

Detailed Description

The health benefits of orange consumption have been described; however, the specific bioactive compounds responsible for these effects, as well as the underlying mechanisms of action, are not fully understood. There are several varieties of sweet oranges, each with a unique phytochemical profile and potentially distinct health-promoting properties. The 'Rosy Red Valencia' sweet orange is enriched in carotenoids such as lycopene, phytoene, and phytofluene, whereas the commonly consumed 'Olinda Valencia' contains negligible levels of these compounds.

This randomized, parallel-arm clinical trial aims to evaluate and compare the antioxidant and anti-inflammatory effects of 'Rosy Red Valencia' and 'Olinda Valencia' sweet orange consumption in healthy men and women. Participants will be randomized to consume one of the two orange varieties twice daily for four weeks.

The study includes both an acute phase (1-day consumption) and a chronic phase (4-week daily consumption). Blood samples will be collected at baseline, after 1 day, and after 4 weeks of consumption to assess changes in plasma carotenoid concentrations, markers of oxidative stress and inflammation, and gene expression profiles in peripheral blood mononuclear cells. Fecal samples will be collected at baseline and after 4 weeks to assess the effects on gut microbiota composition. By evaluating and comparing the biological effects of these two orange varieties, the study aims to elucidate the role of specific carotenoids in mediating the health benefits of sweet orange consumption.

Study Timeline

• Status Verified: 2025-04
• Study Start: 2025-04-17
• Study First Submitted: 2025-04-17
• Study First Submitted QC: 2025-04-17
• Last Update Submitted: 2025-04-17
• Study First Posted: 2025-04-25
• Last Update Posted: 2025-04-25
• Primary Completion: 2025-10-01
• Study Completion: 2026-01-30

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 20

Inclusion Criteria

Not provided

Exclusion Criteria

• Pregnancy/lactation
• History of cardiovascular diseases, diabetes, uncontrolled hypertension, heart failure, stroke, liver, gallbladder, kidney, thyroid disease, gastrointestinal, autoimmune disorder, or cancer.
• Psychiatric disease that interferes with the understanding and implementation of the intervention
• History of eating disorders (such as bulimia nervosa and anorexia nervosa) in the last 5 years
• Current smokers
• Vegan, vegetarian, or other special diets (e.g., keto, paleo)
• Use of antibiotics or laxatives in the previous month
• History of substance abuse or alcohol abuse
• involvement in a weight loss intervention program within the past month or weight change > 10%
• Self-report of allergic reactions to study products or their phytochemicals.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Levels of lycopene and noncolored carotenoids	0, 1 day, 4 weeks	Levels in plasma

Secondary Outcome Measures

Name	Time	Method
Oxidative stress markers	0, 1 day, 4 weeks	Markers of oxidative stress in plasma/ blood cells
Inflammatory markers	0, 1 day, 4 weeks	Markers of inflammation in plasma
Gene expression	0, 1 day, 4 weeks	Gene expression in Peripheral Blood Mononuclear Cells (PBMCs)
Lipid/metabolic profile	0, 4 weeks	Measured in blood samples
Blood pressure	0, 4 weeks
Microbiota composition	0, 4 weeks	From stool samples

Trial Locations

Locations (1)

Nutrition Department, Ragle Facility, University of California Davis; 🇺🇸 Davis, California, United States