Reflection spectroscopy-assessed skin carotenoids are sensitive to change in carotenoid intake in a six-week randomized controlled feeding trial in a racially/ethnically diverse sample

Authors: JILLCOT PITTS, S - East Carolina University; MORAN, N - Children'S Nutrition Research Center (CNRC); LASKA, M - University Of Minnesota; WU, Q - East Carolina University; HARNACK, L - University Of Minnesota; MOE, S - University Of Minnesota; CARR-MANTHE, P - University Of Minnesota; GATES, E - East Carolina University; CHANG, J - Baylor College Of Medicine; ZAIDI, Y - Baylor College Of Medicine; GELINEAU, A - University Of Minnesota; BERG, L - University Of Minnesota; CRAFT, N - Craft Nutrition Consulting

Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/13/2023
Publication Date: 4/3/2023
Citation: Jillcot Pitts, S., Moran, N.E., Laska, M.N., Wu, Q., Harnack, L., Moe, S., Carr-Manthe, P., Gates, E., Chang, J., Zaidi, Y., Gelineau, A., Berg, L., Craft, N.E. 2023. Reflection spectroscopy-assessed skin carotenoids are sensitive to change in carotenoid intake in a six-week randomized controlled feeding trial in a racially/ethnically diverse sample. Journal of Nutrition. 153:1133-1142. https://doi.org/10.1016/j.tjnut.2023.02.017.
DOI: https://doi.org/10.1016/j.tjnut.2023.02.017

Interpretive Summary: Assessing what the population eats is critical for carefully studying the relationship between nutrition and health. Optical skin carotenoid measurements can provide an assessment of carotenoid intake. Carotenoids are red, orange, yellow components found predominantly in fruits and vegetables. In this study, adults consumed low, medium or higher amounts of carotenoids in a fruit and vegetable juice for 6 weeks to mimic the amount of change one might expect with the addition of more vegetables in the diet. This controlled trial found that skin carotenoid and plasma carotenoid measurements increase in diverse US adults in response to controlled increases of carotenoid intake. Skin carotenoid biomarkers demonstrate robustness in diverse populations and defined responses over a fixed amount of time, making them an appealing biomarker to measure in nutrition research and health monitoring studies.

Technical Abstract: Reflection spectroscopy, utilized by the Veggie Meter®, is a less expensive, non-invasive method to quantify skin carotenoids and is a valid approximation of FV intake. However, it is unknown to what degree Veggie Meter®-assessed skin carotenoid score change is responsive to changes in carotenoid intake. To evaluate Veggie Meter®-assessed skin carotenoid score response in a 6-week randomized controlled trial of a carotenoid-containing juice to determine if the Veggie Meter® can be used to detect nutritionally-relevant changes in carotenoid intake; and to compare skin and plasma carotenoid responses to the 6-week trial. In this 6-week trial, participants (n = 162) who self-identified as one of four US racial/ethnic groups (25% Black, 25% Asian, 27% non-Hispanic White, 23% Hispanic) were randomized to a control group, receiving negligible carotenoids (177 mL apple juice/day), moderate-dose group, receiving 4 mg total carotenoids/day (177 mL orange-carrot juice/d), or high-dose group, receiving 8 mg total carotenoids/day (355 mL orange-carrot juice/d). Skin carotenoid score and plasma total carotenoid concentrations (alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, lutein, zeaxanthin) were assessed at baseline, three weeks, and six weeks (n=158 completed the trial). Repeated measures linear models were used to examine skin and plasma carotenoids over time and between groups. At six weeks, participants in the high-dose and moderate-dose groups had significantly higher mean skin carotenoid scores (414.0 (standard deviation = 100.6), 369.7 (standard deviation = 100.3), respectively) compared to those in the control group (305.2 (100.5)). In the high dose group, there was a 42% change in skin carotenoids from baseline (mean=290.4) to 6-week follow-up (increase of 123, 123/290 = 42.4%). There was a 61% change in the plasma carotenoids in the high dose group. In conclusion, the Veggie Meter® is sensitive to increases in daily carotenoid intake in diverse racial/ethnic groups over a 6-week period.