AgingNCT06879626
Effect of Snacks on Aging
A study testing Pecan and Pretzel in people with Aging, run by University of California, Los Angeles at 1 site in United States.
Trial summary
The purpose of this study is to determine if daily consumption of 2 oz of pecans compared to 3.5 oz pretzel snacks for 12 weeks will 1) contribute to the body's ability to protect itself from oxidative damage (caused by oxygen radicals created by ultraviolet (UV) B light) by evaluating skin resistance to UV light… Read more about this study
- Who is it for?
- Ages 55 to 75 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Aging
- What is being tested?
- Pecan and Pretzel
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteUnited States
- Study dates
- 19 May 2025to 31 Dec 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 55 to 75 years
- Women only
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Female
- Generally healthy
- Aged 55-75 years
- BMI 18.5-34.9 kg/m2
- Fitzpatrick Skin type II-IV
- Consume a typical Western diet (low in polyphenols-rich foods and fiber)
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- Willing to maintain habitual dietary and exercise patterns for the study duration
- Willing to maintain normal skin care products and pattern for the duration of the study
- Willing to come to study visits without any makeup and skin products on
- Subjects must read and sign the Institutional Review Board-approved written informed consent prior to the initiation of any study specific procedures or enrollment. A subject will be excluded for any condition that might compromise the ability to give truly informed consent.
Who cannot join
- Vegetarian/vegan
- Known nut allergy
- Skin-related prescription medication, supplements or non-prescription cosmeceutical agents
- Initiation of topical or oral prescription steroids and/or anti-inflammatory medications within 30 days prior to study enrollment
- Excessive exposure to either natural or artificial sunlight
- Screening laboratory values outside of the normal range that is considered clinically significant for study participation by the investigator
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- Documented chronic disease
- Taking medications or supplements known to affect gut microbiota composition (antibiotics within the past 3 months, probiotics, fiber, etc.)
- Taking exogenous hormones (e.g. hormone replacement therapy)
- Recent weight fluctuations (>10% in the last 6 months)
- Smoker or living with a smoker
- Use of >20 g of alcohol per day
- Unable or unwilling to comply with the study protocol (including unwillingness to avoid nuts for the whole duration of the study)
- Unable to provide consent
- Pregnancy and/or lactation
Trial locations and contacts
1 site in 1 country.
United States1 site
UCLA Center for Human Nutrition
Los Angeles, California, 90095
About this study
Official title: Effect of Pecan Consumption on Aging
The purpose of this study is to determine if daily consumption of 2 oz of pecans compared to 3.5 oz pretzel snacks for 12 weeks will 1) contribute to the body's ability to protect itself from oxidative damage (caused by oxygen radicals created by ultraviolet (UV) B light) by evaluating skin resistance to UV light irritation, skin fats/oils degradation and "rusting", and oxidative damage to the skin genes; and 2) explore the mechanisms of how snack consumption may affect aging by analyzing blood markers of aging as well as the microbes living in the gut (gut microbiome).
Read the detailed description
Oxidative stress plays a significant role in the aging process. Antioxidant potential of tree nuts, including pecans, has been previously reported. However, very few studies have evaluated the antioxidant effects and their underlying mechanisms of nut consumption in the aging population. Skin is the largest organ and is the first body part to exhibit signs of aging. Human skin exposed to solar ultraviolet radiation (UVR) experiences a dramatic increase in production of reactive oxygen species (ROS) and inflammation. Moreover, skin aging is associated with increased levels of oxidative stress. Investigators previously showed that almond and pomegranate consumption can improve the antioxidant defense of skin by reducing UV-induced damage. In addition, the prebiotic properties of nuts and other bioactive-rich foods have been of great interest lately, current study team and others have reported the gut microbiome modulating effects of tree nut consumption. Based on this evidence and other published data, it is being proposed that pecans, due to their bioactive compound content, may have the potential to contribute to whole body antioxidant protection, modulate the gut microbiome and affect the aging process. The aim of this study is to evaluate the effects of incorporating 2 oz of pecans into diet compared to isocaloric pretzel snacks daily for 12 weeks 1) on whole body antioxidant capacity by evaluating skin resistance to UV irritation, lipid oxidation, and oxidative DNA damage; and 2) explore the mechanism of how pecan consumption affects aging by analyzing circulating biomarkers of aging as well as the gut microbiome. This will be a two-arm, randomized, placebo-controlled intervention study in 60 middle-aged and older generally healthy non-vegetarian/vegan women (age 55-75 years, Fitzpatrick's skin types II-IV). Investigating the effects of pecan consumption on skin antioxidant defense and systemic oxidative status will uncover valuable new insights into whether bioactive compounds in pecans can contribute to the total body antioxidant capacity and affect the aging process.
- Conditions
- Aging
- Being tested
- Pecan, Pretzel
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PecanOther
2 oz of whole raw pecans
PretzelOther
3.5 oz of pretzel snacks daily
| Study group | Role | What they receive |
|---|---|---|
| Pecan arm | Experimental | Participats in this arm will be comsuming 2 oz of pecans daily for 12 wekks Receives: Other: Pecan |
| Pretzel arm | Experimental | Participants in this arm will consume 3.5 oz of pretzel snacks daily for 12 weeks Receives: Other: Pretzel |
What is being measured
The primary outcome is the main question the study is designed to answer.
Minimal Erythema Dose (MED)
To determine the minimal erythema dose (MED) at the inner arm, skin UVB dose and treatment time will be determined based on overall skin type classification. Based on overall skin type classification we will use the National Biological UVB mJ chart to determine the dose and sequential exposure times for each skin patch. A sleeve with 6 cutout patches will be placed on participant's arm. Using the Dermalight 90 handheld device (National Biological, Beachwood, OH) each cutout test area on the inner arm of subjects will be exposed to a defined dose of narrow band ultraviolet B (NB-UVB) light delivered by the UV exposure between 270 and 400 nm. Each cutout window will be exposed to an increasing dose. To evaluate the minimal erythema dose (MED) participants will need to return 24 hours later to determine which skin patch showed minimal erythema (pink color). Although 6 cutouts will be made, this is a single outcome measure as the all 6 cutouts will all be measuring MED in mJ/cm^2.
Measured: At baseline and 12 weeks
Secondary outcomes (4)
Skin characteristics
skin elasticity (Cutometer Dual MPA 580) in N/m
Measured: At baseline and 12 weeks
Skin characteristics
hydration (Corneometer CM 825) in AU
Measured: At baseline and 12 weeks
Skin characteristics
color (Mexameter MX18) in AU
Measured: At baseline and 12 weeks
Skin characteristics
skin gloss (SkinGlossymeter GL200) in GU
Measured: At baseline and 12 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Mar 2025
- Study start19 May 2025
- Primary completion12 Jun 2026
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for AgingStudies of the same condition, open and under way.
- More trials run by University of California, Los AngelesThe 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
- Double blind
- Who is masked
- Investigator, Outcomes assessor
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of California, Los Angeles
- Sponsor type
- University, hospital or other
- Collaborators
- American Pecan Promotion Board
- Responsible party
- Principal investigator, Zhaoping Li, University of California, Los Angeles
- Investigators
- Zhaoping Li, MD, PhD, Principal investigator, University of California, Los Angeles
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06879626
- Sponsor's protocol ID
- IRB-25-0037
- Status last verified
- Jul 2026
- First submitted
- 11 Feb 2025
- Last updated
- 31 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Data analysis will be performed in-house.
Study at a glance
From the registry record, last updated by the sponsor on 31 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Pecan Consumption on Aging
- ClinicalTrials.gov ID
- NCT06879626
- Acronym / sponsor ID
- IRB-25-0037
- Conditions
- Aging
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- University of California, Los AngelesUniversity, hospital or other
- Collaborators
- American Pecan Promotion Board
- Study start
- 19 May 2025 (actual)
- Primary completion
- 12 Jun 2026 (actual)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 17 Mar 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.
The purpose of this study is to determine if daily consumption of 2 oz of pecans compared to 3.5 oz pretzel snacks for 12 weeks will 1) contribute to the body's ability to protect itself from oxidative damage (caused by oxygen radicals created by ultraviolet (UV) B light) by evaluating skin resistance to UV light irritation, skin fats/oils degradation and "rusting", and oxidative damage to the skin genes; and 2) explore the mechanisms of how snack consumption may affect aging by analyzing blood markers of aging as well as the microbes living in the gut (gut microbiome).
Detailed description
Oxidative stress plays a significant role in the aging process. Antioxidant potential of tree nuts, including pecans, has been previously reported. However, very few studies have evaluated the antioxidant effects and their underlying mechanisms of nut consumption in the aging population. Skin is the largest organ and is the first body part to exhibit signs of aging. Human skin exposed to solar ultraviolet radiation (UVR) experiences a dramatic increase in production of reactive oxygen species (ROS) and inflammation. Moreover, skin aging is associated with increased levels of oxidative stress. Investigators previously showed that almond and pomegranate consumption can improve the antioxidant defense of skin by reducing UV-induced damage. In addition, the prebiotic properties of nuts and other bioactive-rich foods have been of great interest lately, current study team and others have reported the gut microbiome modulating effects of tree nut consumption. Based on this evidence and other published data, it is being proposed that pecans, due to their bioactive compound content, may have the potential to contribute to whole body antioxidant protection, modulate the gut microbiome and affect the aging process. The aim of this study is to evaluate the effects of incorporating 2 oz of pecans into diet compared to isocaloric pretzel snacks daily for 12 weeks 1) on whole body antioxidant capacity by evaluating skin resistance to UV irritation, lipid oxidation, and oxidative DNA damage; and 2) explore the mechanism of how pecan consumption affects aging by analyzing circulating biomarkers of aging as well as the gut microbiome. This will be a two-arm, randomized, placebo-controlled intervention study in 60 middle-aged and older generally healthy non-vegetarian/vegan women (age 55-75 years, Fitzpatrick's skin types II-IV). Investigating the effects of pecan consumption on skin antioxidant defense and systemic oxidative status will uncover valuable new insights into whether bioactive compounds in pecans can contribute to the total body antioxidant capacity and affect the aging process.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Pecan arm | Experimental | Other: PecanParticipats in this arm will be comsuming 2 oz of pecans daily for 12 wekks |
| Pretzel arm | Experimental | Other: PretzelParticipants in this arm will consume 3.5 oz of pretzel snacks daily for 12 weeks |
Who may qualify
- Ages
- 55 to 75 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (10 listed)
- Female
- Generally healthy
- Aged 55-75 years
- BMI 18.5-34.9 kg/m2
- Fitzpatrick Skin type II-IV
Key exclusion criteria (15 listed)
- Vegetarian/vegan
- Known nut allergy
- Skin-related prescription medication, supplements or non-prescription cosmeceutical agents
- Initiation of topical or oral prescription steroids and/or anti-inflammatory medications within 30 days prior to study enrollment
- Excessive exposure to either natural or artificial sunlight
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 |
|---|---|---|
| Pecan2 oz of whole raw pecans | Other | Pecan arm |
| Pretzel3.5 oz of pretzel snacks daily | Other | Pretzel arm |
Primary outcome
Minimal Erythema Dose (MED)
Time frame: At baseline and 12 weeks
To determine the minimal erythema dose (MED) at the inner arm, skin UVB dose and treatment time will be determined based on overall skin type classification. Based on overall skin type classification we will use the National Biological UVB mJ chart to determine the dose and sequential exposure times for each skin patch. A sleeve with 6 cutout patches will be placed on participant's arm. Using the Dermalight 90 handheld device (National Biological, Beachwood, OH) each cutout test area on the inner arm of subjects will be exposed to a defined dose of narrow band ultraviolet B (NB-UVB) light delivered by the UV exposure between 270 and 400 nm. Each cutout window will be exposed to an increasing dose. To evaluate the minimal erythema dose (MED) participants will need to return 24 hours later to determine which skin patch showed minimal erythema (pink color). Although 6 cutouts will be made, this is a single outcome measure as the all 6 cutouts will all be measuring MED in mJ/cm^2.
4 secondary outcomes
Skin characteristics
Time frame: At baseline and 12 weeks
Skin characteristics
Time frame: At baseline and 12 weeks
Skin characteristics
Time frame: At baseline and 12 weeks
Skin characteristics
Time frame: At baseline and 12 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 31 Jul 2026.
- Individual participant dataSharing planned: No. Data analysis will be performed in-house.
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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.
Zhaoping Li, MD, PhD principal investigator
University of California, Los Angeles
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Pecan and Pretzel in people with Aging, run by University of California, Los Angeles 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 10 inclusion and 15 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: under way, not looking for participants, as of the sponsor's last update on 31 Jul 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?
This study is still under way. Results are not available in the source record yet.
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?
Minimal Erythema Dose (MED) (time frame: At baseline and 12 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 31 Jul 2026.