7 replies to this topic

[Sillewater]

http://www.npr.org/t...toryId=12877984

The reason an elephant lives longer than a shrew is not because its heart beats longer. It's because its heart beats slower. So it takes a few more years for the elephant to complete his or her up to one and a half billion beats.

Excess cardio bad? Just enough cardio to bring down your heart beat is good? Not so much a theory of aging in my opinion but if holds true maybe a limit to the cell function.

[rwac]

http://www.npr.org/t...toryId=12877984

Excess cardio bad? Just enough cardio to bring down your heart beat is good? Not so much a theory of aging in my opinion but if holds true maybe a limit to the cell function.

http://www.upi.com/S...31961236777577/

Dividing the mice into those with the top 25 percentile of metabolic rates, compared with the lowest 25 percentile, revealed that those in the top 25 percentile had 30.2% greater daily energy expenditure and lived on average 36% longer lives.

http://jeb.biologist...208/9/1717.full

[churchill]

Not sure about this theory, if you compare the mouse vs bats, I think they have similar heart rates but bats last much longer.

[niner]

Naked Mole Rat. I think the 1.5B heartbeat theory has some holes in it. Aside from that, isn't it just a variation on a metabolic rate theory?

[Sillewater]

Dividing the mice into those with the top 25 percentile of metabolic rates, compared with the lowest 25 percentile, revealed that those in the top 25 percentile had 30.2% greater daily energy expenditure and lived on average 36% longer lives.

http://jeb.biologist...208/9/1717.full

In this case colder temperatures may be inducing protective mechanisms just like CR (there was that rodent study where warmer temperatures decreased the effects of CR, and indeed many stress pathways are increased by cold temperatures), thus countering the increased metabolic rate, of course the metabolic rate theory may not even be true because there are many types of damage that result in aging.

Naked Mole Rat. I think the 1.5B heartbeat theory has some holes in it. Aside from that, isn't it just a variation on a metabolic rate theory?

Naked mole rats have slower heart rates and metabolic rates I believe (just increased oxidative stress), that is why they crowd together (well one of the reasons). Some reasons they do live longer despite the increased stress is more resistant proteins, increased autophagy of the type that helps, and better maintained antioxidant systems.

I posted it out of interest, if it is true all animals only live for 1.5bn heart beats, its quite a beautiful parallel.

[Shepard]

If biological systems were static and not plastic systems, I'd likely give the idea more merit. Although, deep down, this is the type of idea that I normally find interesting against my better judgement. Nature doesn't tend to be that kind to mathematicians.

Edited by Shepard, 19 December 2011 - 11:40 PM.

[Sillewater]

If biological systems were static and not plastic systems, I'd likely give the idea more merit. Although, deep down, this is the type of idea that I normally find interesting against my better judgement. Nature doesn't tend to be that kind to mathematicians.

Very true, however with mathematics an average gives you one number. Maybe the SD of the 1.5bn is like 500m. In any case the researcher thinks he has a case, I would like to see the paper he publishes on the topic.

[steampoweredgod]

The thread on membrane composition is relevant to metabolic rate discussion.