Betterhumans reports on modest healthy life extension in mice, achieved by boosting their protection from damaging free radicals. "Rabinovitch and colleagues focused on the enzyme catalase, which helps convert hydrogen peroxide into water and oxygen. This is important because hydrogen peroxide is a waste product of metabolism that can be a precursor of free radicals. The researchers studied mice with a genetic variation that made them produce extra human catalase. ... Mice with higher catalase levels in the mitochondria had about a 20% increase in average and maximum lifespan." Scientists have already shown that life extension at this level is quite plausible through manipulation of metabolic processes.