Skin carotenoid status and plasma carotenoids: biomarkers of dietary carotenoids, fruits and vegetables for middle-aged and older Singaporean adults

Skin carotenoid status (SCS) measured by resonance Raman spectroscopy (RRS) may serve as an emerging alternative measurement for dietary carotenoid, fruit and vegetable (FV) intake although its application had not been assessed in a middle-aged and older population in Asia. This cross-sectional study aims to concurrently examine the use of SCS and plasma carotenoids to measure FV and carotenoid intake in a middle-aged and older population, taking into consideration potential socio-demographic and nutritional confounders. The study recruited 103 middle-aged and older adults (mean age: 58 years) in Singapore. Dietary carotenoids and FV, plasma carotenoid concentration and SCS were measured using 3-d food records, HPLC and a biophotonic scanner which utilised RRS, respectively. Adjusted for statistically defined socio-demographic covariates sex, age, BMI, prescription medication and cigarette smoking, plasma carotenoids and SCS showed positive associations with dietary total carotenoids (beta (plasma): 0 center dot 020 (95 % CI 0 center dot 000, 0 center dot 040) mu mol/l/mg, P = 0 center dot 05; beta (skin): 265 (95 % CI 23, 506) arbitrary units/mg, P = 0 center dot 03) and FV (beta (plasma): 0 center dot 076 (95 % CI 0 center dot 021, 0 center dot 132) mu mol/l per FV serving, P = 0 center dot 008; beta (skin): 1036 (95 % CI 363, 1708) arbitrary units/FV serving, P = 0 center dot 003). The associations of SCS with dietary carotenoid and FV intake were null with the inclusion of dietary PUFA, fibre and vitamin C as nutritional covariates (P > 0 center dot 05). This suggests a potential influence of these nutritional factors on carotenoid circulation and deposition in the skin. In conclusion, SCS, similar to plasma carotenoids, may serve as a biomarker for both dietary carotenoid and FV intake in a middle-aged and older Singaporean population.

Automated summary

Skin carotenoid status (SCS) measured by resonance Raman spectroscopy (RRS) and plasma carotenoids can serve as biomarkers for dietary carotenoid and fruit and vegetable (FV) intake in middle-aged and older Singaporeans, taking into account potential confounders like socio-demographics and nutritional factors.