Are you making the argument that before the availibity of hormonal replacement therapy, there was no statistcally adjusted difference in lifespan?
I agree with you that there is a hormonal component. T is a necessary part of the hormone cascade, but high levels are not a universally good thing. Point of fact. CRed mammals have lower T levels in their younger years and higher average levels in old age compared to baseline. Higher levels of SHBG. Eunuchs have lower levels of T and live longer. I'm oversimplifying for the sake of keeping things short, but you get the point- It's more complex than a linear relationship, but lower average levels of unbound T are a good thing in otherwise healthy people, or they come about from disorders such as metabolic syndrome which skew the statistics into appearing that low T levels are bad. A reverse correlation. As I pointed out earlier in the thread that high T levels can depress the immune system.
You say that it has nothing to do with cell proliferation, are you also saying that T has a negligable effect of cell proliferation?
ROS are not universally bad for us either. Part of the benefit of exercise comes from the generation of ROS and the resultant hormetic response. Otherwise healthy people have lower levels of unbound T as well as low levels of ROS.
As for eggs, they are there from birth but in immature form. Thats high school level bio.
Females might be more taxed by shedding of the endomitrial lining and blood loss. Unlike germ cells, those tissues are not immortal.
I think that there are probably some repair and maintenance signalling pathways involved that are turned up when a male is not getting sex, similar to CR, to preserve him for when it becomes available. Maybe that vitality is carried into the immune system. This is a deeply held belief in traditional chinese medicine. It might be that telomerase is expressed more in somatic cells when sexual functions go dormant.
Glad to talk to you!
I don't know whether the signal pathway of CR and that of "sex restriction" are similar, but there are some experiments show that CR will reuduce sexuality. It's now no doubt that excess sex can decrease our bodys' repairing activities. Chinese medicine here are concordant with modern medicine.
By the way, I come from China.
Glad to talk to you too my friend. I think that chinese medicine was ahead of its time and has a lot that we can learn from.
Not so much that hormones are the major player, just that healthcare has had more benefits to offer women than men. Virtually no women die in child birth these days, but it was once more common. The emergence of modern medicine has had a huge beneficial effect on the lifespans of women. Perhaps this is a cause of men not being as concerned (except for women not wanting to date men w/o healthcare) about healthcare because it just doesn't offer enough personal benefits. Men have traditionally been providers of it rather than consumers, giving it to their families, perhaps the men of the past never wanted it for themselves. However the nature of it, and it's transition to being universal or at least quasi-universal has changed the playing field. Healthcare must now benefit men and women to the same extent. It can't choose an unbalanced effort. It there is disparity in lifespan, it creates inequality and men have the same right to live longer/healthier and more full lives as a result of healthcare as women do.
I don't think such genocidal abberations as eunuchs or such far off circumstances should at all be part of the argument for lower sexual hormones equaling longer lifespans. CR is no more than a short term gain in terms of immortality. It's something that offered a glimmer of hope, but now we need to move on because CR is just too limited for our purposes. CR seems to dominate our mindset however and despite showing no lifespan benefits in primate tests, people still cling to it as though it should be part of the argument. We really just don't know enough about CR consider the changes it causes in rodents to be beneficial phenotypes for us to aspire to. I think that despite being oversimplified, the argument still can't be corrected for the loss of human experience and existence. To live is to be swept up in the chemistry that determines us. The lowered sex hormone lifestyle is IMHO much more conducive to selfishness. Obesity leads to selfishness and if an overweight person starves, they often become less selfish. It was common practice for starvation to be used as a form of punishment and this is why. Obesity also lowers the levels of sex/gender specific hormones by diffusion into greater mass and what I'll call metabolic noise for lack of a better education. So optimally, a life consists of higher sex/gender hormones and an optimal weight or a higher sex/gender hormone to weight ratio. This results in a greater enjoyment of life and existence. Pressing one way or another is sub optimal for the purposes of indefinite LS. To me calorie restriction is about having a greater sensitivity to a more pure body chemistry. Even when I fast or when I get sick, I make sure to eat to increase my sex hormone levels. It just seems to be the best for my body and my existence. Put it this way, when we are younger, almost all of us experience higher levels of sex/gender hormones and we find it very enjoyable. We get older and life is less enjoyable, so we seek to hold on to our youthful phenotypes, esp. those of us here. Distancing ourselves from gender specific and sexual health is just plain unhealthy. I feel like I may be rambling... it's getting late here.
Quick answers:
I'm saying that for the purpose of immortality hayflick limits are useless, they are just giving us a number to beat or perhaps an optimal number of base pairs for telomere length. I think the study with rats that had a kill switch for senescent cells is more useful to us and that a tighter control and more frequent flicking of that kill switch will preserve youth, reverse aging, and contribute to much longer indefinite lifespans in the endgame.
I'm not familiar with the hormetic response as a term, but I'm quite certain that the body has a mechanism or habit for performing incomplete repairs which leads to senescence and that process needs to improved or fixed in a way that has a negligible or non interfering effect on human existence/experience.
By some explanations, every cell in our body was present from the time that we were an embryo. In any case, as it has been shown that egg cells can still be made later in life, we can no longer assume in any way that a woman is born with a finite number of eggs which makes HS Bio very misleading. I'm just not for filling fresh heads with nonsense.
Edited by cryonicsculture, 22 January 2013 - 06:55 AM.
LongeCity
