ARVO 2023: Hydrogen-rich water in the treatment of retinal degeneration

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Reviewed by Ruri Sugiyama, MD

Ruri Sugiyama, MD, the lead study author from Nihon University, Tokyo, Japan, reported that hydrogen-rich water may have a place in treatment of retinal degeneration. The team of investigators found that the hydrogen-rich water significantly improved the retinal blood flow (RBF) dysregulation in type 2 diabetic mice. She reported the findings at the Association for Research in Vision and Ophthalmology annual meeting.

Dr. Sugiyama explained that molecular hydrogen reduces oxidants such as hydroxyradical and peroxynitrite, which have high oxidative activity. This was demonstrated in a previous study that showed that mice that drank hydrogen water had neuroprotective effects against retinal degeneration.¹

The researchers took their study a step further to determine the effects of hydrogen water on RBF dysregulation in diabetes, which has not been investigated. They analyzed the changes in the RBF in response to flicker stimulation and systemic hyperoxia, which are the indices of retinal neurovascular coupling in diabetic mice.

Twelve db/db obesity-induced diabetic male mice with a mutation in the leptin receptor were included. One group of 6 mice had access to non-hydrogenated water, and a second group of 6 mice had access to hydrogen-rich water (1.2-1.6 parts/million) from age 6 weeks. The following parameters were evaluated every 2 weeks from ages 8 to 14 weeks: body weight, blood glucose level, intraocular pressure (IOP), and blood pressure. Every 2 weeks, laser speckle flowgraphy-micro was used to measure the RBF in the vascular area of the optic disc as the mean blur rate in the resting state and in the responses to flicker stimulation and hyperoxia. The investigators also evaluated the glial activation based on immunofluorescence, she explained.

The blood pressure, body weight, IOP, and RBF in the resting state did not differ markedly between the groups. The blood glucose level was significantly lower in the hydrogen-rich water group at the end of the study (p=0.03), although the level remained high (median, 427 mg/dL).

Importantly, the RBF in response to flicker stimulation and hyperoxia improved significantly in the hydrogen water group compared with the controls group from 8 weeks of age and persisted throughout the study. The increased expression of glial fibrillary acidic protein decreased in the hydrogen-rich water group, the investigators reported.

The research team concluded that the RBF dysregulation improved significantly as the result of intake of hydrogen-rich water in the mice with type 2 diabetes. They also speculated that hydrogen may benefit the dysregulated retinal neurovascular coupling due to activation of retinal glial cells.

Reference:

1. Igarashi T, Ohsawa I, Kobayashi M, et al. Drinking hydrogen water improves photoreceptor structure and function in retinal degeneration in 6 mice. Sci Rep. 2022;10 :12:13610.