Molecular Hydrogen as an Emerging Candidate for Preventing
We recently published a paper describing that drinking hydrogen water (water infused with hydrogen gas) improved Alzheimer’s Disease Assessment Scale-cognitive subscale (ADAS-cog) scores in subjects with mild cognitive impairment (MCI) in apolipoprotein E4 (APOE4) genotype-carriers by a randomized, double-blind, placebo-controlled clinical trial . In the present mini-review, we introduce molecular hydrogen (H2) as an emerging candidate for preventing Alzheimer’s disease (AD).
AD is a progressive multi-factorial neurodegenerative disorder, in which oxidative stress is widely accepted as one of the causative factors. Currently, no effective treatment is available likely because complicated multiple factors are involved in the pathophysiology of AD. Single modality of a specific target strategy for treating AD may not be successful, and future therapies based on a multiple-target strategy are needed to address the multiple aspects of AD and block its progression.
For a long time, H2 was believed to be a biologically inert and nonfunctional molecule in the body; however, we overturned this concept by demonstrating that H2 protected cultured cells and the brain against excess oxidative stress and proposed its potential for preventive and therapeutic applications. Subsequently, there have been about 1,000 papers published on 170 kinds of animal disease models and more than 30 clinical studies on the use of H2. These studies have revealed that H2 acts as a therapeutic and preventive antioxidant with multiple functions, including anti-inflammation, anti-allergy, anti-cell death, and stimulation of energy metabolism, all of which contribute to its marked efficacy in a variety of diseases. Figure 1 summarizes publications reporting the clinical efficacies by H2 on various kinds of human diseases. As a molecular mechanism by which H2 exerts the multiple functions, H2 might regulate various gene expression levels in indirect manners under transcription factors such as including NFAT and Nrf2.
H2 seems to differ from conventional pharmaceutical drugs because unlike H2 most drugs have specificity for and to act on their exact targets. Owing to its multiple functions and great efficacy coupled with its lack of adverse effects, H2 has great potential for preventing AD.
There are several methods to ingest or consume H2; inhaling H2 gas, drinking H2-dissolved in water (H2-water), injecting H2-dissolved in saline (H2-saline), taking an H2 bath, or dropping H2-saline into the eyes.