Association of candidate single nucleotide polymorphism genotypes with plasma and skin carotenoid concentrations in adults provided a lycopene-rich juice

Authors: NORMAN, ANNA - Baylor College Of Medicine; PALMER, DANIEL - University Of North Dakota; MORAN, NANCY - Baylor College Of Medicine; Roemmich, James; Casperson, Shanon

Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/22/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Carotenoids are the pigments which give fruits and vegetables their yellow, orange, and red color and are deposited in the skin when consumed. In human skin, carotenoids protect against UV radiation to prevent skin damage and protect the skin’s elasticity and moisture. While consuming carotenoid-rich fruits and vegetables is the major contributing factor, genetic variation can also influence carotenoid absorption and tissue accumulation. Therefore, we investigated common variants in genes previously associated with carotenoid metabolism to determine their relationship with skin carotenoid accumulation in response to greater carotenoid consumption. We provided adults a serving of carotenoid-rich vegetable juice that was consumed daily for 8 weeks. The findings from this study suggest that some genotypes predict baseline and post-intervention skin carotenoid concentrations. These novel findings expand upon the understanding of how genetic variation affects inter-individual variation in skin carotenoid phenotypes in humans.

Technical Abstract: Background: Carotenoids are fat-soluble phytochemicals with biological roles, including UV protective functions in skin. Spectroscopic skin carotenoid measurements can also serve as a noninvasive biomarker for carotenoid consumption. Single nucleotide polymorphisms (SNPs) in metabolic genes are associated with human plasma carotenoid concentrations, however their relationship with skin carotenoid concentrations is unknown. Objectives: The objective of this study was to determine the relationship between 13 candidate SNPs with skin and plasma carotenoid concentrations before and after a carotenoid-rich tomato juice intervention. Methods: In this randomized, controlled trial, participants (n=80) were provided with lycopene-rich vegetable juice providing low (13.1 mg), medium (23.9 mg), and high (31.0 mg) daily total carotenoid doses for 8-weeks. Plasma carotenoid concentrations were measured by HPLC and skin carotenoid score was assessed by reflection spectroscopy (Veggie Meter ™) at baseline and end of study. Thirteen candidate SNPs in 5 genes (BCO1, CD36, SCARB1, SETD7, ABCA1) were genotyped from blood using PCR-based assays. Multiple linear regression models tested the effects of the intervention and SNP genotypes on concentrations of skin and plasma carotenoids throughout the study. Mixed models tested the effects of the intervention, visit, interaction between intervention and visit, and SNP genotype on skin and plasma carotenoids. Baseline carotenoid intake, BMI, gender, and age are covariates in all models. Results: Genotypes for BCO1 rs7500996 (p=0.0446) and CD36 rs1527479 (p=0.0049) were associated with skin carotenoid concentrations when baseline and the final week of the intervention were used. BCO1 rs12934922 (p=0.0427) and CD36 rs1527479 (p=0.0335) genotypes were associated with baseline skin carotenoid concentrations. BCO1 rs4889286 (p=0.0061) and BCO1 rs4889293 (p=0.0482) were associated with plasma lutein & zeaxanthin concentrations. Conclusions: These novel associations between SNPs and skin carotenoid concentrations expand upon the understanding of how genetic variation affects inter-individual variation in skin carotenoid phenotypes in humans.