Determination of S- and/or R-equol in plant-based food products and efficacy of topical or oral 4′,7-isoflavandiol (R/S equol) to improve skin health in adult men, a Placebo-controlled pilot study

Abstract

There were two purposes for this investigation: 1) determine if S- and/or R-equol is present in seven plant-based food products and 2) to establish if topical or oral R/S equol administration improved skin health in adult men. First, the presence of R- and/or S-equol was determined by high performance liquid chromatography (HPLC) in commercial food products. Next, in a small pilot study R/S equol topically applied (once per day) was tested in a split-face study for 7 weeks in men (n = 3). Finally, the oral application of R/S equol (6 mg/day) in men (37 to 56 years of age) via a placebo-controlled pilot study was performed for 12 weeks (n = 11 per treatment group). By HPLC analysis, 6 of the 7 foods tested had S-equol and/or R-equol present. Topically applied R/S equol in a split-face study improved the nasolabial fold/crease by 4 weeks and by 7 weeks the skin wrinkle was almost undetectable in one subject. Finally, in the low dose oral R/S equol placebo-controlled study all five skin parameters displayed improvement over baseline and/or control values. These results suggest that R- and/or S-equol is present in plant-based food products and topical or oral R/S equol improved skin health in men.