Two spectroscopy devices can approximate fruit and vegetable intake in a racially and ethnically diverse sample

Authors: JILCOTT PITTS, STEPHANIE - East Carolina University; WU, QIANG - East Carolina University; LASKA, MELISSA - University Of Minnesota; MORAN, NANCY - Children'S Nutrition Research Center (CNRC)

Submitted to: Current Developments in Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/19/2025
Publication Date: 6/4/2025
Citation: Jilcott Pitts, S.B., Wu, Q., Laska, M.N., Moran, N.E. 2025. Two spectroscopy devices can approximate fruit and vegetable intake in a racially and ethnically diverse sample. Current Developments in Nutrition. 9(7). Article 107482. https://doi.org/10.1016/j.cdnut.2025.107482.
DOI: https://doi.org/10.1016/j.cdnut.2025.107482

Interpretive Summary: Carotenoids are colorful orange and yellow compounds in fruits and vegetables that support health. This study looked at two different tools that measure the amount of yellow coloration in the skin to see if they can help estimate how many fruits and vegetables people eat, based on skin carotenoid concentrations. Data collected from two earlier studies was used to compare measurements of skin carotenoids using two devices: the Longevity Link Veggie Meter and a Konica Minolta CM 700D spectrophotometer. Participants were also asked about their diets using surveys. Then, the skin color results were compared between the two devices and with blood levels of carotenoids and reported fruit and vegetable intake. Skin lightness and redness measured by the Konica Minolta spectrophotometer didn’t show strong links to diet or carotenoid levels. But skin yellowness measured by the Konica Minolta spectrophotometer had a strong correlation to carotenoid levels in the skin measured by the Veggie Meter and in the blood, especially for certain carotenoid types like beta-carotene, but not for lycopene. Skin yellowness also agreed with how many fruits and vegetables people said they ate. Both devices can help estimate fruit and vegetable intake. However, they may not work as well for measuring lycopene, a carotenoid found in tomatoes. More research is needed to understand why.

Technical Abstract: To compare the relative validity of two different skin spectrophotometry devices to serve as biomarkers of plasma carotenoid concentrations, self-reported fruit and vegetable intake (FVI), and carotenoid intake, to examine if both devices can be used to approximate FVI. Human skin carotenoid scores (SCS, Veggie Meter®-assessed) and color space measurement data from two prior studies were used. Participants’ skin color space parameters (lightness, redness, and yellowness) were measured using the Konica Minolta CM 700D spectrophotometer. Self-reported diet was assessed using food frequency questionnaires. We analyzed data from the two prior studies to examine correlations of skin lightness, redness, and yellowness parameters with SCS, plasma carotenoids, and FVI and carotenoid intake. Skin lightness and redness demonstrated weak correlations with skin carotenoids (r = -0.15-0.14), plasma carotenoids (r = -0.19-0.21), and FV and carotenoid intake (r = -0.14-0.13). Conversely, skin yellowness demonstrated statistically significant (p < 0.05/63) correlations with SCS ranging from r = 0.60 to r = 0.67. The correlations between skin yellowness and total plasma carotenoids (r = 0.46-0.57), plasma a-carotene (r = 0.38-0.54), ß-carotene (r = 0.50-0.57), a- and B-cryptoxanthin (r = 0.38-0.43), and lutein and zeaxanthin (r = 0.30-0.48) were all statistically significant (p < 0.00079), but the correlation between skin yellowness and plasma lycopene was not statistically significant (r = 0.06 - 0.17). There were positive, statistically significant correlations between skin yellowness and FVI in Study 1 (r = 0.27), as well as positive, statistically significant correlations between changes in skin yellowness with changes in SCS (r = 0.51), changes in total plasma carotenoids (r = 0.45), and changes in plasma a-carotene (r = 0.51) and B-carotene (r = 0.45). Both devices can be used to approximate FVI. More research is needed to understand reasons the devices may not detect plasma lycopene well.