From what I've heard/read telomere length as the anti-aging curing may be a bit overrated, because we actually want to prevent cognitive degeneration (who cares if you live longer if you can't think as well). There's a very interesting ongoing study called the Lothian Birth Cohort Study, where they tested cognitive functioning in 11 year olds born in Edinburgh in the years 1921 and 1936. In the late 1990s/early 2000s the individuals were tracked down (now in their 70-80s) and researchers did extensive, extensive testing to try to explain variances in cognitive functioning between their scores at age 11 and now (why did some people lose ability/others gain?)

I talked to the director of this massive study and he said there was no correlation with cognitive functioning and telomere length [1] and the entire thing may be a bit overrated. Interestingly enough though, he said there there was a strong correlation with DNA methylation[2] with increased methylation associated with worse cognitive aging.

Very interestingly, DNA methylation decreased for Scott after his time in space...

[1] https://www.ncbi.nlm.nih.gov/pubmed/21194798 [2] https://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?...