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

Not Applicable

Completed

• Conditions: Overweight
• Interventions: Other: Low dose vegetable juice; Other: High dose vegetable juice; Other: Control bottled water; Other: Medium dose vegetable juice

• Registration Number: NCT03202043
• Lead Sponsor: USDA Grand Forks Human Nutrition Research Center

Brief Summary

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

Detailed Description

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.

Study Timeline

• Study First Submitted: 2017-06-26
• Study First Submitted QC: 2017-06-26
• Study First Posted: 2017-06-28
• Study Start: 2018-04-06
• Primary Completion: 2019-05-21
• Study Completion: 2019-05-21
• Status Verified: 2022-05
• Last Update Submitted: 2022-05-09
• Last Update Posted: 2022-05-16

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 80

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Low dose vegetable juice	Low dose vegetable juice	Subject will consume low dose vegetable juice daily for 8 weeks.
High dose vegetable juice	High dose vegetable juice	Subject will consume high dose vegetable juice daily for 8 weeks.
Control bottled water	Control bottled water	Subject will consume control bottled water daily for 8 weeks.
Medium dose vegetable juice	Medium dose vegetable juice	Subject will consume medium dose vegetable juice daily for 8 weeks.

Primary Outcome Measures

Name	Time	Method
Change in skin carotenoid concentration as measured by pressure-mediated reflection spectroscopy (RS)	0, 4, 8 weeks	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.

Secondary Outcome Measures

Name	Time	Method
Usual intake of carotenoid-rich foods and beverages	0,4,8 weeks	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.

Trial Locations

Locations (1)

USDA Grand Forks Human Nutrition Research Center; 🇺🇸 Grand Forks, North Dakota, United States