It's Never Too Late: Calorie Restriction is Effective in Older Mammals

Interestingness: 6

By Michael Rae, in Rejuvenation Research, May 2004, 7(1): 3-8. doi:10.1089/154916804323105026.

This is the first issue where the journal is actually called Rejuvenation Research.  It seemed to be a bit of a rebranding to try to disassociate from the general anti-aging crowd, and also when they switched from Michael Fossel to Aubrey de Grey as editor.  From the looks of this issue, it's a very positive change.

Most of this short review paper concerns itself with details of genetic profiles of calorie restricted (CR) vs all you want to eat (AD) mice, molecular differences shown, and potential problems with studies regarding CR and CR-mimetics.

There are two interesting bits for me. One is a graph showing proportion increase in lifespan in mice vs number of days under CR.  There is a reasonable straight line of best fit, with 45% increase in lifespan reached at around 1800 days on CR.

The other interesting bit is a table showing percentage of increased lifespan on mice when CR was started at weaning (1 month), 12 months (two of these), and 19 months.  Mean lifespans for these studies on the CR branch were 43, 37, 33 and 35 months respectively.  These represented 130, 119, 113 and 115 percent of control lifespans for each one.  Also, they lived 31, 18, 16 and 40 percent longer than controls from the point of starting CR.  Those are big numbers for percentage increase from starting point.

(That 19% longer on average vs 18% longer on average of remaining time for the second study seems dodgy to me.  It'd seem to imply the mice that did CR were already living 18% longer prior to start of CR).