Why do food change in color, flavor and nutrient content, when exposed to air? Why do fats in foods become rancid causing the food to go bad?
The culprit is Oxidation.
The same Oxidation is also taking place in our body all the time producing Free Radicals.
Our body produces natural Antioxidants to counter these free radicals all the time.
When there is an imbalance between the Free Radicals and Antioxidants produced, Oxidative Stress occurs.
Persistent Oxidative Stress is now clinically linked to age-related chronic diseases (e.g. diabetes, cardiovascular diseases, chronic obstructive pulmonary diseases, chronic kidney disease, etc. 
Persistent Oxidative Stress is also linked to sarcopenia (loss of lean muscle mass) and frailty.
 Ilaria Liguori et.al., Oxidative stress, aging, and diseases, Clinical Interventions in Aging, 2018:13
When Persistent Oxidative Stress happens, our body needs some help. The best help you can offer is to use H2:iD Molecular Hydrogen. Scientists have discovered the Antioxidant + Anti-Inflammatory + Cytoprotecting + Signal Modulation effect of Molecular Hydrogen
 individual variability in results may occur. Consult your physician to help you review your blood test results. Some individuals may take longer time to see positive results.