The Juice Study: Sensitivity of Skin Carotenoid Status to Detect Change in Intake

Study Overview
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Brief Summary
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This study is designed to see if drinking a tomato-based vegetable juice will increase skin carotenoids.

Detailed Description
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The US Dietary Guidelines for Americans recommends that individuals consume approximately 2-4 c of vegetables each day to reduce risk of chronic disease, but current methods for assessing intake are either inaccurate (self-report) or invasive (blood carotenoid levels). Recent research indicates that skin carotenoid status may be a useful biomarker of vegetable intake, but the sensitivity to dose in unknown. In this study, we propose to test the dose-response of skin carotenoids to consumption of 3 different levels of vegetable juice (with a control group receiving water). We will test skin carotenoids in two ways: using resonance Raman spectroscopy (RRS), which we have previously validated, and with a new technique, pressure mediated reflection spectroscopy (RS; the Veggie Meter). We will compare the two techniques during an 8-week provided tomato-based juice intervention. Skin carotenoid readings will be compared to blood carotenoid concentrations and single nucleotide polymorphisms (SNPs) of genes related to the uptake, transport, and metabolism of carotenoids will be examined in blood and saliva.

Official Title
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Sensitivity of Skin Carotenoid Status to Detect Changes in Intake of Varying Levels of Vegetables

Conditions
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Overweight

Intervention / Treatment
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* Other: High dose vegetable juice
* Other: Medium dose vegetable juice
* Other: Low dose vegetable juice
* Other: Control bottled water


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI 18.5-29.9 kg/m2 Exclusion Criteria: weigh less than 110 lbs currently dieting to lose weight allergic to tomatoes or vegetables pregnant, lactating, or planning to become pregnant currently use tobacco products or vape eat more that 2 cups of vegetables per day have high blood sugar (≥200 mg/dL) have high blood pressure (≥140/90 mm Hg) have a medical condition such as diabetes or high blood pressure taking medication that lowers cholesterol or triglycerides

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High dose vegetable juice<br>Subject will consume high dose vegetable juice daily for 8 weeks. | Other: High dose vegetable juice<br>* High dose (13 fl oz) vegetable juice<br>|
| Experimental: Medium dose vegetable juice<br>Subject will consume medium dose vegetable juice daily for 8 weeks. | Other: Medium dose vegetable juice<br>* Medium dose (10 fl oz) vegetable juice<br>|
| Experimental: Low dose vegetable juice<br>Subject will consume low dose vegetable juice daily for 8 weeks. | Other: Low dose vegetable juice<br>* Low dose (5.5 fl oz) vegetable juice<br>|
| Other: Control bottled water<br>Subject will consume control bottled water daily for 8 weeks. | Other: Control bottled water<br>* Control (12 fl oz) bottled water<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in skin carotenoid concentration as measured by pressure-mediated reflection spectroscopy (RS) | Pressure-mediated reflection spectroscopy (RS) is used to measure tissue carotenoids. RS intensity can be used as a measure for total carotenoid content in the measured tissue volume. | 0, 4, 8 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Usual intake of carotenoid-rich foods and beverages | A 44-item food frequency questionnaire of the top carotenoid-rich foods and beverages will be developed to measure carotenoid intake from a person's usual diet. | 0,4,8 weeks |