Examining Validity and Sensitivity of Pressure-Mediated Reflection Spectroscopy
Condition: Dietary Habits; Diet, Healthy
MeSH terms: Hypersensitivity
Study type: Interventional

Summary: 
      The central goal of this proposal is to examine validity and sensitivity of RS-assessed skin
      carotenoid status as a marker of F&V intake in a racially and ethnically diverse sample of
      individuals. First, investigators will examine the association (RS Device Validity) between
      RS-assessed skin carotenoids and the primary outcomes of objectively-measured plasma
      carotenoids and self-reported F&V consumption across four diverse groups:
      African-American/Black, Asian, White, and Hispanic/Latino (n=213). Then the investigators
      will conduct a randomized controlled trial to define the relative skin carotenoid responses
      (RS Device Sensitivity) across racial-ethnic groups, in comparison with plasma carotenoid
      responses. The investigators will conduct a 6-week randomized controlled trial of a
      carotenoid-containing juice intervention [placebo control, low and high dose juice (N=156).
      Finally, the genetic basis for racial/ethnic group differences in skin carotenoid responses
      to diet will be investigated through hypothesis-driven genomic analysis of participants from
      Aims 1 and 2.
    

Detailed description: 
      A diet rich in fruits and vegetables (F&Vs) is associated with lower risk of
      nutrition-related chronic diseases and all-cause mortality. Despite these benefits, the US
      population under-consumes F&Vs, with particularly low intake in disadvantaged populations.
      Low F&V intake results in higher rates of nutrition-related chronic disease among
      disadvantaged populations when compared with more advantaged populations. Detecting and
      addressing inadequate F&V intake in these populations is needed to reduce such disparities.
      Yet, there is still no commonly used predictive, objective measure of F&V intake for
      surveillance or determination of policy or intervention effectiveness. The current objective,
      "gold standard" marker of F&V intake is blood carotenoid concentration-an expensive,
      time-intensive, and invasive measurement. Traditional methods of self-reported dietary
      assessment are imprecise and have diminished utility in rural and disadvantaged populations
      due to low literacy, numeracy, and internet connectivity. In the past decade, skin carotenoid
      status assessed by non-invasive resonance Raman spectroscopy (RRS) has emerged as a promising
      biomarker of F&V intake. Reflection spectroscopy (RS) is an improvement over RRS, offering
      stronger signals, faster data acquisition, and greater portability in a commercially
      available device (Veggie Meter, Longevity Link Corporation). However, a hurdle impedes use of
      RS in scientific studies: to date, nearly all of the non-invasive skin carotenoid validation
      has been conducted in non-Hispanic whites, primarily by RRS. Therefore, it is critical to
      evaluate RS in racially and ethnically diverse populations. The central goal of this proposal
      is to examine validity and sensitivity of RS-assessed skin carotenoid status as a marker of
      F&V intake in a racially and ethnically diverse sample of individuals. First, the
      investigators will examine the association (RS Device Validity) between RS-assessed skin
      carotenoids and the primary outcomes of objectively-measured plasma carotenoids and
      self-reported F&V consumption across four diverse groups: African-American/Black, Asian,
      White, and Hispanic/Latino (target n = 320 but due to Covid-19, N=213). Then the
      investigators will conduct a randomized controlled trial to define the relative skin
      carotenoid responses (RS Device Sensitivity) across racial-ethnic groups, in comparison with
      plasma carotenoid responses. The investigators will conduct an 6-week randomized controlled
      trial of a carotenoid-containing juice intervention [placebo control, low and high dose juice
      across 4 genetically-stratified racial-ethnic groups (goal n = 156). Finally, the genetic
      basis for racial/ethnic group differences in skin carotenoid responses to diet will be
      investigated through hypothesis-driven genomic analysis of participants from Aims 1 and 2.
      The results of this study will prepare RS for mass deployment in population surveillance
      studies and community-based intervention trials, ultimately leading to more accurate
      determination of the most effective strategies to reduce health disparities related to low
      F&V intake in the United States and beyond.
    

Intervention name(s): High carotenoid juice; Placebo control - Apple juice
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): Juice with high carotenoids; Juice with negligible carotenoids
Intervention MeSH terms: Carotenoids
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: First, investigators will examine the association (RS Device Validity) between RS-assessed skin carotenoids and the primary outcomes of objectively-measured plasma carotenoids and self-reported F&V consumption across four diverse groups: African-American/Black, Asian, White, and Hispanic/Latino. Then investigators will conduct a randomized controlled trial to define the relative skin carotenoid responses (RS Device Sensitivity) across racial-ethnic groups, in comparison with plasma carotenoid responses. Investigators will conduct a 6-week randomized controlled trial of a carotenoid-containing juice intervention [placebo control, low and high dose juice across 4 genetically-stratified racial-ethnic groups (n = 156).
Masking: None (Open Label)
Primary purpose: Prevention