A Two-Year, Double-Blind, Randomized Placebo-Controlled Trial of Oral Green Tea Polyphenols on the Long-Term Clinical and Histologic Appearance of Photoaging Skin

Abstract

Long-term supplementation with oral GTPs was not superior to placebo in improving clinical or histologic photoaging parameters after 24 months of use.

Can dietary intake influence perception of and measured appearance? A Systematic Review

“…The age range of participants was 18 to 77 years, with one study not reporting the age of participants. The duration of studies ranged from seven days to a two-year intervention [25]. Fourteen interventions ranged from 8 to 14 weeks, two less than 8 weeks, two were 24 weeks [26,27] and one two-years [25].…”

“…The duration of studies ranged from seven days to a two-year intervention [25]. Fourteen interventions ranged from 8 to 14 weeks, two less than 8 weeks, two were 24 weeks [26,27] and one two-years [25]. Only one study followed up participants after the end of the intervention which was an initial 6-week intervention with a further 6-weeks follow-up [28].…”

“…Polyphenols [27,39], Omega 3 fatty acids [27,32,39], carotenoids [21], [32,36], [27,37] , vitamins E [27,36,37,39] and C [36] [27,37], Lactobacillus (La1) probiotics [29], green tea polyphenols [25,30,33], squalene [31], red ginseng [26] , and flavanol cocoa [34], whilst only one measured the effect derived from whole foods [28] which used foods high in beta-carotene.…”

“…Three studies [25,30,33], which evaluated the effects of green tea supplementation; orally or topically, found no significant differences in facial wrinkling. Another study investigating the…”

“…Thirteen studies had two intervention arms (control/intervention) [25][26][27][29][30][31][32][33][34][35][36][37][38], two had one arm [29] , one had three [39] and one had six intervention arms [28]. The majority of studies (15 out of 17) evaluated the effect of various dietary supplements with several active…”