Understanding the genetic controls of ageing could lead to more therapies that forestall it.
Genetics has a much larger role in how long a person lives than previously thought, finds a new analysis that challenges decades of scientific consensus.
About 55% of the human lifespan is heritable, meaning that more than half of observed variation in longevity across a population is attributable to genetics. That is a far greater proportion than the 10%–25% previously estimated, according to the research, which was published today in Science1.
The findings should aid in the quest to find specific genes involved in ageing and to develop treatments, says study co-author Ben Shenhar, a biophysicist at the Weizmann Institute of Science in Rehovot, Israel.
“There is much to be learnt from the genetics of ageing if we can understand what genes are responsible for healthy ageing,” he says.
Twin efforts
Shenhar and his colleagues say that previous estimates were far too low because they did not effectively separate deaths caused by extrinsic factors, such as infectious diseases or accidents, from intrinsic ones inside the body, such as the gradual decline of organ function stemming from DNA damage over time.
No surprise here. It’s the inescapable conclusion one reaches looking at studies of centenarians and supercentenarians, as well as various health fanatics. If your body was only made for 85, then no matter how strongly you adhere to the very optimum of lifestyle, diet and exercise, at best you will fulfill your potential of 85, while the sloppy guy with bad habits will cruise to 105 because that’s what his body was designed for. This is why extreme exercise or diets strike me as bonkers if they come at the cost of QOL. Exercise and eat “well enough”, and leave the extremes to those who get a kick out of it, and you’ll get 99.999% if not 100% of the benefits anyway.
Our only hope at present, before genetic engineering comes along, is that a smart cocktail of drugs might push you slightly outside your body design - that’s where rapamycin and other drugs come in. They might, or might not work, ultimately. Right now we just don’t know, and we’re rolling the dice the best we can. YMMV.
CRON did not represent - at least initially any hardship. Hunger abated after a few weeks, and I really had no issues. I did it for a little over eight years. I ultimately gave it up not so much because of QOL issues as practicality - unless practicalities are cosidered part of QOL. I felt fantastic - better than at any point in life (including now). But it became very socially isolating. I couldn’t go out with friends to restaurants or invite friends for meals at home or go to theirs, or take long vacations, or easily meet with clients and collaborators (in my business lunch was obligatory - but now I’m retired from that). Shopping and food prep were a major hassle and a time (and mental energy) sink. Stuff like that. So I gave it up, though I maintain lowish calories to this day, from force of habit (and health considerations). In the end, I felt like it just was not a practical diet given my lifestyle and circumstances.
Btw. I took CR very seriously, which means I tried to do as good a job as I possibly could. Here’s an example of how that made it very hard socially: you can’t just sit in a restaurant with a salad if you’re on CR, or be around food period. Here’s why: research shows that the benefits of CR are abolished if you even smell food. This was intially established in flies. Look it up, it’s wild.
Apparently people in Loma Linda California have a median lifespan of about 90 (89 for males, 91 for females), and they have a pretty genetically diverse population, as I understand it (so, it’s not like they all have some magic genes). So, at least this shows that diet and lifestyle can get most people to about 90; and maybe a little more, like 95 or higher, if you try to optimize it (which I don’t think people in Loma Linda do) and throw in an optimal mix of pills like Rapamycin and various supplements.
The real gains will come when we get more radical methods, like greatly expanded anti-cancer therapies, perhaps mitochondrial replacements, and even tiny robots to repair the body.