Did Cecil even begin to answer this question? I don’t think the question was: What measures can I take to ensure that I’ll live a few extra healthy years? I think it was: is there anything we can do (or will soon be able to do) that will significantly lengthy our lifespan? Not how do I live to be a healthy 85, but how do I retard aging so that I pass away at, maybe, 200? Apart from ‘Stop thinking’, which isn’t really a serious response, Cecil totally ignored the gist of the question, didn’t he? I think the expected answer was supposed to delve into interesting research concerning the causes of aging.
Anyway, I’m just a 600-post shmuck, and Cecil is… well, by many accounts, a difficult, capricious chap named Ed, but I’d still like to see a response to the question: Is there any real hope of something that could allow humans to stop or slow the aging process?
Calorie restriction, as described in the column, is the best current bet. After that, heavy-duty genetic engineering, which would probably have to be prenatal since you’d want to hit all the cells in the body.
Aging isn’t just a macrophysiological phenomena; it actually occurs at the cellular level. At the ends of chromosomes are regions of non-functional (from a replicative point of view) DNA called telomeres. As the genetic information in cells is replicated during cell division, the telomeres get shorter and eventually effective replication becomes difficult. Nobody knows for sure why this is or exactly what role telomeres play and whether they’re causative or indicative but it is likely that aging is a byproduct of mechanisms intended to limit the effects of mutation and compound replicative error; mitochondrial DNA (which is separate from nuclear DNA) is especially sensitive to this due to its primary function of regulating oxidative reactions. Since the behavior and extent of the role of mitochondria is still not well understood it may be a long time before technological solutions exist to significantly increase longevity.
[Extreme] calorie restriction–diets of <1200 calories/day–as mentioned in the linked SD article) does seem to provide some benefit to longevity, but at the cost of reduced activity and the potential for malnutrition. However, more modest calorie reduction and selecting a diet low in saturated fats and high in soluble fiber and a wide variety of flavonoids (from fruits and leafy green vegetables) epidemiologically offers somewhat greater lifespan, and more importantly, a greater period of healthy and functional activity, allowing one to make better use of the time one has. The Cecil article briefly mentions residents of Okinawa (who have a traditional diet low in saturated fats and dairy, high in vegetables, and with moderate lean protein intake–mostly fish and shellfish) has having a slightly higher average longevity than Americans (4 years), but he fails to go into any detail, particularly the difference in longevity and healthy between the younger, post-WWII generations of Okinawans who consume a Westernized diet, and the older generations who have maintained traditional eating and social patterns described above. From the Okinawa Centenarian Study, a 25 year study of the diets and lifestyles of Okinawan seniors, there is a pronounced difference in both longevity and the incidence of chronic diseases associated with aging, including heart disease, arthritis, and various cancers. These differences between the results in seniors and in the younger generations suggest that genetics plays only at most a modest role in the longevity and health of Okinawans. Note that the results of the study were not just that diet influenced health and aging, but exercise, rest, and social activity had significant influence. Some pokes have been made at the methodology of the study but I have yet to see anything that definitively undermines it or reasonably indicates alternative causation.
So the answer is, you can’t really stop aging, but you can mitigate the effects to a measurable degree by diet, exercise, and lifestyle. That isn’t going to let you live to 120, but it may well have you being a healthy and active 90 year old, which is better than being laid up with heart disease at 70.
When I was in grad school I got plenty of sleep, spent a few hours a day in the gym, and had very low stress. People thought I was 10 years younger than I actually was. After graduating I took a high-stress, long-hours job, and I started aging much faster. Now, after almost 10 years of limited exercise, insufficient sleep, and bad diet I’m starting to look my age. Basically I seemed to age two years for every year of chronological age.
Given that, my suggestion for not getting older is to quit your job.
Cecil should have started his response with your statement, and then he should have gone on to write (and maybe elaborate upon) Stranger on a Train’s first paragraph. I don’t want to speak for the person who asked the question, but I think Stranger’s first paragraph gets to the heart of the matter. Thanks.
Q about alcohol consumption and health: Is there any trustworthy data to support this?
I ask because in the last few years there have been two studies that supported the “1-2 drinks is good” idea, but both were found to be duds. One ~3 years ago turned out had put dry alcoholics in the “non-drinker” category and once they were put in the “drinker” category it came out as expected. Then last year or so a meta-study (which are easy to game) came out that turned out to have been funded by the liquor industry. The journal and the med school were extremely unhappy about this since such funding is supposed to be disclosed upfront.
It seems like all studies end up like this. Since the pro-drinking announcement gets a lot of press and the “oops” announcement gets little, I suspect that a lot of what is generally “well known” about this might be bogus.
As I understand it, telomeres may be a red herring as far as a cause of aging goes. You actually have cells with their full set of telomeres. They are known as stem cells and can be found in most, if not all, tissues of the body.
Normally, when stem cells divide, one of the daughter cells is a stem cell and one is of whatever tissue the the cell is part of. It’s probable (although I don’t know if it’s been shown yet) that most of the healing from injuries is done by stem cells. But they also just keep tissues from shrinking as the regular cells die off.
Unfortunately, as you age, stem cells eventually stop working correctly. A few wear out, but most just stop producing non-stem cells. They divide into two more stem cells. Which doesn’t help your tissues any.
We don’t know what mechanism stems use to detemine which daughter cell is another stem cell and which is a tissue cell. If we knew, perhaps we could find a way to keep them working correctly. And that might help you avoid getting old.
[Note: I’ve simplified things a bit, but you can read more on stem cell division at Stem cell - Wikipedia ]