No, hydrogen cannot serve as a substitute for oxygen in the human body. While hydrogen is a fundamental element and plays various roles in biochemical processes, it does not fulfill the same critical functions that oxygen does.
Oxygen is essential for cellular respiration, a process that occurs in the mitochondria of cells, where it helps convert glucose and other nutrients into energy (ATP). This process is vital for sustaining life, as energy is required for nearly all bodily functions.
Hydrogen, on the other hand, is mainly involved in the formation of water (H2O) in the body and acts as a building block in various organic compounds. It also plays a role in redox reactions but does not participate in the energy generation process in the same effective way that oxygen does.
Moreover, while there has been research into the potential therapeutic benefits of hydrogen as a molecule, these applications do not imply that hydrogen can replace oxygen. In sum, oxygen is irreplaceable when it comes to the metabolic processes that keep us alive.