tag:blogger.com,1999:blog-37148773.post5745620735375782558..comments2024-03-27T14:50:47.345-04:00Comments on <center>Sandwalk</center>: Grey hair may be protecting us from cancerLarry Moranhttp://www.blogger.com/profile/05756598746605455848noreply@blogger.comBlogger7125tag:blogger.com,1999:blog-37148773.post-58586247348919196662012-09-03T18:26:15.069-04:002012-09-03T18:26:15.069-04:00if grey hair increases the level of solar radiatio...if grey hair increases the level of solar radiation that reaches the scalp, could it be a means of increasing vitamin D production in older people, given that vitamin D production in oldies is less efficient than in younger people? Of course this would also increase risk of melanoma, but maybe that is evolutionarily desirable in that it knocks off older people quickly. So my hypothesis is that greying hair (and baldness and hair thinning) increases the usefulness of older people in raising their grandchildren by improving their health via increased vitamin D production, and if this comes at the expense of skin cancer, then they do not remain a burden for their offspring for long.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-37148773.post-51262408478714248362009-06-23T16:40:18.863-04:002009-06-23T16:40:18.863-04:00If you have to invent an evolutionary purpose for ...If you have to invent an evolutionary purpose for grey hair, its use as an indicator to predator animals that this post-reproductive individual is a good candidate for culling from the herd comes to mind. Likewise the grey hair is a good message to those younger members of the herd to turn elsewhere when looking for a reproductive partner.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-37148773.post-53954901348461653212009-06-23T14:29:29.826-04:002009-06-23T14:29:29.826-04:00Purposefully over-interpreting the data is the bre...Purposefully over-interpreting the data is the bread and butter of science fiction, or science-informed fiction. <br /><br />Maybe that's what New Scientists is morphing into.gilltnoreply@blogger.comtag:blogger.com,1999:blog-37148773.post-8648349028435231072009-06-23T01:58:21.691-04:002009-06-23T01:58:21.691-04:00Might changes in MSC regulation also come w/ a ca...Might changes in MSC regulation also come w/ a cancer risk? I guess it really depends on exactly what type of cancer you're interested in (i.e. which cells become cancerous). Other test ideas assuming you could reasonably control for "DNA damage" levels: <br /><br />1. Do patterns of gray on individuals correspond to sun exposure or other sources of DNA damage? What about cancer development?<br /><br />2. Do blonds go gray as frequently as dark-haired individuals?<br /><br />3. Do darker skinned people (more protected DNA?) go gray at frequently as lighter skinned people (presumable more easily damaged DNA?)?<br /><br />Other than the mammal connection, is this mechanism likely to be seen in people, or just mice??Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-37148773.post-71451370333750524472009-06-23T01:44:19.168-04:002009-06-23T01:44:19.168-04:00Thanks for the info. Now i understand why hair tur...Thanks for the info. Now i understand why hair turns gray.Tina Mckenziehttp://wellbeing-guru.livejournal.com/3638.htmlnoreply@blogger.comtag:blogger.com,1999:blog-37148773.post-79783265110650707632009-06-22T22:58:49.940-04:002009-06-22T22:58:49.940-04:00I'm bald, so I shouldn't have to worry abo...I'm bald, so I shouldn't have to worry about anything.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-37148773.post-85102010108635471122009-06-22T13:47:20.996-04:002009-06-22T13:47:20.996-04:00Wouldn't it have to be "people with darke...Wouldn't it have to be "people with darker hair" (or less grey hair really, since hair colour at least to some extent correlates with skin colour, which correlates with skin cancer risk, iirc) and similar levels of sun exposure?Ianhttps://www.blogger.com/profile/01010178962574928062noreply@blogger.com