Many laboratory studies have shown that H2 gas, even in the small quantities present in H2-saturated water, can reduce cytotoxic oxygen species in artificially-induced cell damage in cell cultures or in rats:Hydrogen acts as a therapeutic antioxidant: Nature Medicine 13, 688 - 694 (2007) A ...
The settlers cut down the trees to clear lands, make boats and provide rolling logs to move the idols of their ancestors into place. The problem was that they brought rats with them. The rats ate palm seeds so no new palm trees grew. Eventually they stripped the island of all its trees...