Effectiveness of Dietary Supplement for Skin Moisturizing in Healthy Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Abstract

BackgroundThe dietary supplement industry offers many oral cosmetics that purportedly assist in skin moisturization often with unclear evidence supporting efficacy and safety. To update the accessible proofs pertaining to the safety and effectiveness of oral dietary supplements to facilitate skin moisturizing via an all-around review and meta-analysis.MethodsThree on-line databases [Pubmed, Embase, and Cochrane Library (CENTRAL)] were retrieved from January 2000 to November 2021. An overall 66 randomized controlled trials (RCTs) of skin care were recognized. Meta-analysis was performed for dietary supplements with four or more available research.ResultsOral collagen or ceramide resulted in a statistically significant increase in skin hydration and a decrease in transepidermal water loss (TEWL) compared to placebo. No benefits regarding the improvement of skin conditions in terms of water content and TEWL were observed for lactic acid bacteria or Lactobacillus fermented foods. A statistically significant and positive effect on skin hydration was observed for both hyaluronan and procyanidin, with an unknown effect on TEWL due to insufficient RCTs. There was a non-significant improvement in the water content of stratum corneum for astaxanthin based on subgroup analyses. Among the dietary supplements trialed in ≤ 3 RCTs, the judgment regarding their effects on skin moisturizing was prevented by inconsistent conclusions as well as insufficient research. All food supplements were safe throughout the research (normally ≤ 24 weeks).ConclusionOral dietary supplements, including collagen, ceramides, hyaluronan, and procyanidin, were proven to be effective for skin moisturization. At present, for skin moisturization, the proofs supporting the recommendation of other dietary supplements, such as lactic acid bacteria and astaxanthin, are insufficient.Systematic Review Registrationhttp://www.crd.york.ac.uk/PROSPERO/ identifier CRD42021290818

Efficacy and Safety of the Genistein Nutraceutical Product Containing Vitamin E, Vitamin B3, and Ceramide on Skin Health in Postmenopausal Women: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

“…In addition, our results are supported by the fact that the topical application of 4% genistein has been shown to increase skin thickness and blood vessels [ 26 ], the concentration of hyaluronic acid, glycosaminoglycan, and fibroblasts in the dermis [ 27 ], as well as the amount of type I and type III facial collagen [ 17 ], all of which are factors leading to a reduction in skin wrinkles. Moreover, apart from genistein, the GEN product contained some other active substances, including vitamin E [ 12 , 28 ], vitamin B3 [ 19 , 29 ], and ceramide [ 20 , 30 ], all of which have evidence indicating their anti-wrinkle properties [ 31 ].…”

“…Ceramides, which are sphingolipids presenting in the intercellular space of the stratum corneum, play an essential role in structuring and maintaining the barrier property of the epidermis and exhibit a certain level of efficacy in improving skin dryness [ 15 , 16 ]. Although there are several in vitro and in vivo studies on the benefits of genistein [ 17 ], vitamin E [ 18 ], vitamin B3 [ 19 ], and ceramide [ 20 ] alone, limited studies have been conducted to assess the effects of their combined regimen on facial skin.…”

Adjuvant treatment with yupingfeng granules for recurrent respiratory tract infections in children: A systematic review and meta-analysis

“…The difference in outcome after the trial intervention was calculated as the difference between the baseline and endpoint values. Since the included studies did not report the baseline-final correlation coefficient (Corr), we chose the commonly utilized value of 0.5 as the Corr value ( 26 , 27 ). We performed a meta-analysis when at least four studies included the same outcome measure and showed 95% CIs for statistical results, with P < 0.05 representing statistical significance.…”

Effects of Oral Collagen for Skin Anti-Aging: A Systematic Review and Meta-Analysis

“…Cao et al reported that the concentration of moisture in the skin of mice treated with collagen peptides (CPs) was significantly higher compared with that of the control mice (p < 0.05) [55]. Sun et al revealed that collagen as a single supplement showed remarkable effects on skin hydration, with an SMD of 0.77 (95% CI 0.60, 0.94; p < 0.00001) compared with a placebo [56].…”