Effectiveness of Dietary Supplement for Skin Moisturizing in Healthy Adults:

A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Publication Date:
2022-06-02

Institutions involved:

Department of Medical Cosmetology, Hospital of Chengdu University of Traditional Chinese Medicine, China
Dermatology Department, Hospital of Chengdu University of Traditional Chinese Medicine, China
Haisco Pharmaceutical Group Company Ltd., Chengdu, China

Participants:
Participants were healthy adults across multiple studies; specific demographics vary by trial

Duration:
Most included RCTs had durations of ≤24 weeks

Dosage:
Dosages varied across studies; not standardized in the meta-analysis

Learn more

Key Takeaways:

This meta-study frames skin hydration as a key factor in maintaining youthful appearance— that dryness highlights wrinkles, and hydration helps preserve skin smoothness and elasticity.

Procyanidins from apples (and other plants) help your skin hold onto moisture— resulting in a smoother, more youthful appearance from the inside out.

Among dozens of ingredients analyzed, procyanidins were one of only four (alongside hyaluronan, collagen, and ceramides) to show a statistically significant improvement in skin hydration.

Apple Poly Summary:

Why is this study important? This is the first large-scale meta-analysis to evaluate the effectiveness of oral supplements— including procyanidins— for skin hydration. It provides a high-confidence evidence tier for ingestible beauty products, and confirms that procyanidins have a statistically significant benefit for skin moisture.

In Plain English: This study looked at dozens of clinical trials to see which supplements help keep skin hydrated. It found that procyanidins— natural compounds found in apples and other plants— can help improve skin moisture when taken by mouth.

For Medical Professionals: This systematic review and meta-analysis of 66 RCTs found that oral supplementation with procyanidins, hyaluronan, collagen, and ceramides significantly improved skin hydration in healthy adults. Procyanidins demonstrated a statistically significant positive effect on hydration. No safety concerns were reported across trials ≤24 weeks.

Abstract:

Background: The 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.

Methods: Three 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.

Results: Oral 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).

Conclusion: Oral 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 Registration: http://www.crd.york.ac.uk/PROSPERO/ identifier CRD42021290818

Sun, Qian, et al. “Effectiveness of Dietary Supplement for Skin Moisturizing in Healthy Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.” Frontiers in Nutrition, vol. 9, 2022, Article 895192. https://doi.org/10.3389/fnut.2022.895192