HealthyNCT06944210
Evaluation of the Antioxidant and Anti-Inflammatory Capacities of the 'Rosy Red Valencia' and 'Olinda Valencia' Sweet Orange Varieties in Healthy Subjects
A study testing 'Rosy Red Valencia' sweet orange and 'Olinda Valencia' sweet oranges in people with Healthy, run by University of California, Davis at 1 site in United States.
Trial 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… Read more about this study
- Who is it for?
- Ages 25 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- 'Rosy Red Valencia' sweet orange and 'Olinda Valencia' sweet oranges
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 17 May 2025to 6 Mar 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 25 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy men and women
- Age Range: 25-40 years
- Body mass index (BMI) with values between 21 and 29.9 kg^m2
- Willingness to accept randomization, undergo the testing and intervention procedures, and deliver blood and stool samples
- Willingness to refrain from consuming foods rich in lycopene, phytoene, and phytofluene and limit the intake of some polyphenol-rich foods
- Willingness to discontinue the use of antioxidant supplements (such as carotenoid, polyphenol supplements), prebiotics and/or probiotics
Who cannot join
- 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)
Show all 10Show fewer
- 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.
Trial locations and contacts
1 site in 1 country.
United States1 site
Nutrition Department, Ragle Facility, University of California Davis
Davis, California, 95616
About this study
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.
Read the 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.
- Conditions
- Healthy
- Being tested
- 'Rosy Red Valencia' sweet orange, 'Olinda Valencia' sweet oranges
- Keywords
- Oranges, Lycopene, Healthy, Oxidative stress, Inflammation, gene expression
- Medical subject headings
- Inflammation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
'Rosy Red Valencia' sweet orangeOther
The participants consume 2 'Rosy Red Valencia' sweet oranges daily for 4 weeks
'Olinda Valencia' sweet orangesOther
The participants consume 2 'Olinda Valencia' sweet oranges daily for 4 weeks
| Study group | Role | What they receive |
|---|---|---|
| 'Rosy Red Valencia' sweet orange variety | Experimental | The participants of this group consume 'Rosy Red Valencia' sweet oranges Receives: Other: 'Rosy Red Valencia' sweet orange |
| 'Olinda Valencia' sweet orange variety | Experimental | The participants of this group consume 'Olinda Valencia' sweet oranges Receives: Other: 'Olinda Valencia' sweet oranges |
What is being measured
The primary outcome is the main question the study is designed to answer.
Levels of lycopene and noncolored carotenoids
Levels in plasma
Measured: 0, 1 day, 4 weeks
Secondary outcomes (6)
Oxidative stress
Oxidative stress marker DNA/RNA oxidative damage assessed in blood samples from participants by a commercial kit
Measured: 0, 1 day, 4 weeks
Inflammation
Levels of inflammatory marker CRP assessed in blood samples from participants using commercial assay kits.
Measured: 0, 1 day, 4 weeks
Gene expression
Gene expression in Peripheral Blood Mononuclear Cells (PBMCs)
Measured: 0, 1 day, 4 weeks
Microbiota composition
From stool samples
Measured: 0, 4 weeks
Lipid/metabolic profile
Measured in blood samples
Measured: 0, 4 weeks
Systolic and diastolic blood pressure
Measured by automated sphygmomanometer
Measured: 0, 4 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Apr 2025
- Study start17 May 2025
- Primary completion1 Oct 2025
- Study completion6 Mar 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HealthyStudies of the same condition, open and under way.
- More trials run by University of California, DavisThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of California, Davis
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Gerardo G Macknezie, PhD, Study director, Univeristy of California Davis
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06944210
- Sponsor's protocol ID
- 22923441
- Status last verified
- Mar 2026
- First submitted
- 17 Apr 2025
- Last updated
- 11 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 11 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of the Antioxidant and Anti-Inflammatory Capacities of the 'Rosy Red Valencia' and 'Olinda Valencia' Sweet Orange Varieties in Healthy Subjects
- ClinicalTrials.gov ID
- NCT06944210
- Acronym / sponsor ID
- 22923441
- Conditions
- Healthy
- Keywords
- Oranges, Lycopene, Healthy, Oxidative stress, Inflammation, gene expression
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- University of California, DavisUniversity, hospital or other
- Study start
- 17 May 2025 (actual)
- Primary completion
- 1 Oct 2025 (actual)
- Study completion
- 6 Mar 2026 (actual)
- First posted
- 25 Apr 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| 'Rosy Red Valencia' sweet orange variety | Experimental | Other: 'Rosy Red Valencia' sweet orangeThe participants of this group consume 'Rosy Red Valencia' sweet oranges |
| 'Olinda Valencia' sweet orange variety | Experimental | Other: 'Olinda Valencia' sweet orangesThe participants of this group consume 'Olinda Valencia' sweet oranges |
Who may qualify
- Ages
- 25 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (6 listed)
- Healthy men and women
- Age Range: 25-40 years
- Body mass index (BMI) with values between 21 and 29.9 kg^m2
- Willingness to accept randomization, undergo the testing and intervention procedures, and deliver blood and stool samples
- Willingness to refrain from consuming foods rich in lycopene, phytoene, and phytofluene and limit the intake of some polyphenol-rich foods
Key exclusion criteria (10 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 'Rosy Red Valencia' sweet orangeThe participants consume 2 'Rosy Red Valencia' sweet oranges daily for 4 weeks | Other | 'Rosy Red Valencia' sweet orange variety |
| 'Olinda Valencia' sweet orangesThe participants consume 2 'Olinda Valencia' sweet oranges daily for 4 weeks | Other | 'Olinda Valencia' sweet orange variety |
Primary outcome
Levels of lycopene and noncolored carotenoids
Time frame: 0, 1 day, 4 weeks
Levels in plasma
6 secondary outcomes
Oxidative stress
Time frame: 0, 1 day, 4 weeks
Inflammation
Time frame: 0, 1 day, 4 weeks
Gene expression
Time frame: 0, 1 day, 4 weeks
Microbiota composition
Time frame: 0, 4 weeks
Lipid/metabolic profile
Time frame: 0, 4 weeks
Systolic and diastolic blood pressure
Time frame: 0, 4 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Mar 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Gerardo G Macknezie, PhD study director
Univeristy of California Davis
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing 'Rosy Red Valencia' sweet orange and 'Olinda Valencia' sweet oranges in people with Healthy, run by University of California, Davis at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 11 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Levels of lycopene and noncolored carotenoids (time frame: 0, 1 day, 4 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Mar 2026.