A Halloween-themed blog for the spooky season perhaps, but it isn't quite as off-topic as it first appears. In legend, the vampire sought immortality through blood, whether drinking it or — reputedly in the case of Countess Elizabeth Báthory — bathing in it. Whilst immortality is an admittedly desirable form of longevity, fairness dictates we point out the equally striking longevity impact in the opposite direction that befell the vampire's victim. Now, we'll let that brief waltz through vampire legend serve as prelude to a spattering of longevity-related research on the topic of blood.
The warnings from Oeppen and Vaupel notwithstanding, are we as human beings subject to a species-specific maximum lifespan? This is a debate that has raged for some time, and empirical observations seem to tie with postulates from previous research of around 120 to 125 years. Research from last year into the blood of supercentenarian Hendrikje van Andel-Schipper seems to support this idea, suggesting that a ceiling on the number of times our hematopoietic stem cells can divide may place an upper limit on our lives.
But perhaps the role of blood in lifespan may not always require such deep analysis? The most basic classification of blood divides us into eight types. For a while there has been research debate about whether particular blood types might confer greater or lesser longevity. Indeed, very recent research from Italy seems to contradict previous results from Japan, and, although plausible explanations for longevity differentials appear to exist, it is fair to say that the case remains to be proven.
Finally, leaving the most ghoulish to last, let us picture the scene: with thunder crashing off the rooftops, an ancient creature enters into an unnatural union with a youth, and, by taking their blood, miraculously regains youthful vigour. Weather and architecture aside, the previous sentence is a fairly accurate description of some remarkable longevity research involving mice. Rest assured, Count Squeakula has not risen from the grave! Instead, by surgically conjoining the circulatory systems of pairs of young and old mice, researchers have demonstrated rejuvenating effects, specifically striking impacts on brain structure and cognitive processing. Of course, the race is now on to commercialise this effect in people. This research is especially interesting since late-life rejuvenation is considered something of a holy grail. Although in keeping with the season, should that be unholy? There are certainly dystopian wrinkles to be ironed out in a possible future where the vitality of the aged may depend on plasma derived from the young. Hang on a minute — isn't that where we started?
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Villeda, S.A., Plambeck, K.E., Middeldorp, J., et al. (2014) Young blood reverses age-related impairments in cognitive function and synaptic plasticity in mice. Nature Medicine 20:659-663.