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DIFFERENTIAL EFFECTS OF LOW-DOSE AND HIGH-DOSE BETA-CAROTENE SUPPLEMENTION AND THE SIGNS OF PHOTOAGING AND TYPE I PROCOLLAGEN GENE EXPRESSION IN HUMAN SKIN IN VIVO CHO S, LEE DH, WON C ET AL. Danielle Selden and Siona Sammartino
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Vit A Background Retinoids (animal tissues) Retinol, Retinal, Retinoic Acid, Retinyl Esters Pro-Vitamin A Carotenoids (plant derived) Beta-Carotene Beta-Cryptoxanthin Alpha-Carotene Relevant Functions: ***Antioxidant Regulation of Gene Expression (RA)
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Purpose Rationale: Researchers and cosmetic companies are looking for food constituents that can slow cutaneous aging. Previous studies (antioxidant vs pro-oxidant roles) Purpose: To establish how two different dosages of β - carotene affect Photoaging by measuring Facial wrinkles Elasticity UV-Induced DNA Damage Collagen Production and Degradation Visual Changes
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Approach/Methods/Study Design Methods: In-vivo Subjects: 30, healthy females between the ages of 49-68 Mean age 56 Randomized to two groups 30 mg/day of beta-carotene 90 mg/day of beta-carotene Baseline status used for control Duration=90 Days Exclusion Criteria: 2 weeks prior: no use of topical corticosteroids or retinoids 1 month prior: systemic steroid, vitamin intake, phototherapy Smokers
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Approach/Methods/Study Design Measurements At Baseline & Completion Facial Wrinkles & Elasticity Measured Objectively Photographs of face and visiometer technology Facial Erythema and Pigmentation Buttock Skin Type 1 procollagen, matrix metalloproteinase-1, fibrillin-1 mRNA levels and UV-induced thymine dimer and 8-hydroxy-2’- deoxyguanosine formation Other Tools
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Result Highlights 29 subjects completed study Facial wrinkles and elasticity were improved in low- dose beta-carotene group For Wrinkles Measured by Skin Replica and Visiometer For Elasticity Cutometer Clinically visible in some Oxidative damage in UV-Irradiated skin was reduced in low-dose beta-carotene group Assessed via 8-OHdG immunostaining Reduced staining in low-dose group
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Facial Wrinkle Results Baseline90 Days
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8-OHdG Staining 30 mg/day 90 mg/day Baseline 90 Days
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Author’s Conclusions and Implications Wrinkles were improved in 3/5 categories for low dose groups only Low dose beta-carotene showed anti-oxidant effects High dose is inconclusive Need further study Overall, Prevention and repair of photoaging can be achieved by only 30 mg/day of beta-carotene, as shown by reduced wrinkles, increased elasticity in photoaged facial skin, up-regulated pro-collagen expression and reduced UV induced cutaneous DNA damage Doses at 90 mg/day may have deleterious effects
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Limitations Lack of tissue serum and tissue beta-carotene levels pre and post-supplementation Not a Double Blinded Study No Placebo Diet? Fat intake? Small sample size (30 participants) Population?
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Conclusions Too many limitations Author’s did acknowledge this Further research needed for pro-oxidant effects of high dose beta-carotene Author’s acknowledged this Sets the stage for further research Anti-oxidant effects of lose dose beta-carotene seems to be effective Whole foods diet vs. supplementation
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Questions? Q: What primary function of vitamin A can explain the outcomes of this study? Q: After hearing the results of this study, would you promote the usage of beta-carotene supplementation in low-doses in your practice? Why or why not?
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References Cho S, Lee DH, Won C et al. Differential effects of low-dose and high-dose beta-carotene supplementation on the signs of photoaging and type I procollagen gene expression in human skin in vivo. Dermatology. 2010;221:160-171.
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