This opening session focused on interventions that could help to prevent the damage caused by reactive oxygen species (ROS). ROS are produced as a byproduct of normal mitochondrial function, and can damage mitochondrial DNA and other cellular components – for this reason, they play a central role in some theories of aging.
Vladimir Skulachev spoke about his extensive work with SkQ1, an antioxidant targeted to mitochondria. He reported that SkQ1 supplementation extends median lifespan in several species (including mammals), and slows the development of multiple age-related diseases and conditions. His results to date are summarized in this paper; we have also recently discussed his work here.
Holly Brown-Borg talked about the connections between stress resistance and longevity in Ames dwarf mice, which live around 50% longer than normal mice and show elevated levels of some antioxidants. They are working on detangling the complex changes in pathways that contribute to these differences, focusing on the methionine and glutathione metabolic pathways.
James Joseph talked about his investigations into dietary interventions that could help to protect our brains from oxidative damage. The take-home message: eating berries and walnuts can protect against cognitive decline. He also provided some new insights into their possible mechanisms of action.
Cathy Clarke tested an original and interesting approach to avoiding free radical damage to poly-unsaturated fatty acids, or PUFAs: isotope reinforcement. Yeast mutants deficient in Coenzyme Q, an antioxidant that can terminate destructive radical chain reactions, are highly sensitive to PUFAs: they die shortly after being exposed to them and taking them up. However, if the PUFAs are modified in an unusual way – by replacing some hydrogen atoms with the heavier isotope deuterium – then the antioxidant-deficient yeast take up the modified PUFAs and show normal survival. The basic idea here, explained in an earlier paper, is very simple: heavier isotopes make stronger bonds, so isotope-reinforced PUFAs will be more resistant to free radical attack. Will these results transfer to higher organisms? Is there any chance that the deuterium could get incorporated into other molecules, stabilizing proteins that we want to degrade? The authors plan to follow up this study in worms and mice.
(For an index of coverage of all sessions, see here.)