Efficacy and Safety of Oral Green Tea Preparations in Skin Ailments: A Systematic Review of Clinical Studies

Abstract

Green-tea-based products and their polyphenols, especially epigallocatechin-3-gallate, have attracted great attention over the years as possible nutraceuticals, due to their promising bioactivities, especially antioxidant and anti-inflammatory, which could be exploited in several diseases, including skin ailments. In this context, the present study aimed at reviewing clinical evidence about the benefits of the oral administration of green tea preparations and its polyphenols to relieve skin disorders, to point out the current knowledge, and to suggest possible novel strategies to effectively exploit the properties of green tea, also managing safety risks. To this end, a systematic review of the existing literature was carried out, using the PRISMA method. Few studies, including five focused on UV-induced erythema and skin alterations, three on photoaging, two on antioxidant skin defenses, and one on acne and genodermatosis, were retrieved. Despite several benefits, clinical evidence only supports the use of oral green tea preparations to protect skin from damage induced by ultraviolet radiation; in other cases, conflicting results and methodological limits of clinical trials do not allow one to clarify their efficacy. Therefore, their application as adjuvant or alternative sunscreen-protective interventions could be encouraged, in compliance with the safety recommendations.

Nanogel Containing Gamma-Oryzanol-Loaded Nanostructured Lipid Carriers and TiO2/MBBT: A Synergistic Nanotechnological Approach of Potent Natural Antioxidants and Nanosized UV Filters for Skin Protection

“…Furthermore, natural defense mechanisms alone are not sufficient to protect the skin and its cells against such harmful effects of UV radiation. Hence, the inflammatory and oxidative effects of UV radiation on human skin will lead to an increased propensity for the development of several skin diseases, such as atopic dermatitis, psoriasis, acne, and even skin cancer, and are also the main cause of premature/accelerated aging and the development of a decreased capacity for skin regeneration ( Figure 1 ) [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ].…”

Plant Polyphenols and Human Health: Novel Findings for Future Therapeutic Developments

“…At both preclinical and clinical levels, promising benefits have been also highlighted for the oral supplementation of green tea polyphenols in skin ailments, especially with respect to photoprotection, which are likely due to their promising antioxidant, anti-inflammatory, and immunomodulatory effects. However, some issues regarding the clinical efficacy and safety profiles of these preparations remain to be clarified, thus encouraging further studies on the topic [30].…”