Acute effects of daily red wine consumption on retinal and cerebral blood flow in healthy young adults and an animal model

Acute effects of a daily dose of red wine may cause deterioration of visual function; however, there is limited information on healthy individuals. This study aims to investigate acute effects of daily red wine consumption on visual function and retinal microvasculature in healthy young adults through a randomized self-controlled design, and to explore the molecular mechanisms using an animal model. In healthy young adults’ study, 27 adults with follow-up at baseline, 0.5 h, and 2 h after consuming 300-mL of either red wine or water underwent blood biochemistry, visual function, morphology and blood flow of retinal and choroidal vasculatures, and cerebral blood flow (CBF) evaluation. Acute red wine consumption caused abnormal changes in retinal function (mERG) that preceded changes in vision. Macular vessel diameter index (VDI) increased significantly at 0.5 h, but decreased significantly at 2 h, despite increased regional CBF following red wine consumption, which was consistent with increased choroidal thickness and decreased retinal thickness. Animal experiments conducted on Brown Norway rats demonstrated a significant decrease in retinal VDI and vessel area density (VAD) associated with increased ROS production following red wine administration, as well as decreased eNOS and increased ET-1 levels in the retina. Consequently, red wine consumption caused abnormal changes in retinal function and microvascular constriction in healthy young adults, and an animal model suggested that the underlying mechanism may involve the regulation of eNOS and ET-1 levels in the retina. These findings imply the potential detrimental effects of drinking habits on individuals with retinal ischemic diseases.