I'll offer a contrarian view: longevity research, as in the current scope, is about as accurate and useful as Ray Kurzweil's predictions from the 90s.
Let's take caloric restriction, for instance, which is all the rage. Trouble is, all of the evidence we have is in mice or lesser animals, and the comparison is animals on caloric restriction against animals being force fed to the point of obesity. Let me repeat that: in research that shows caloric restriction increasing lifespan in animal models, they are not comparing to animals on a normal diet. So it's entirely plausible all this caloric restriction research findings is just confirmation of the fact that obesity shortens lifespans.
This isn't even touching on the point that correspondence between animal models and humans is abysmally bad. It's the best we have, but there's a very good reason drugs need to go through three stages of human testing after it's been proven successful in animals. With caloric restriction, we don't even have consistent positive results in monkeys, only in rodents.
Has any of this longevity stuff ever been tested in humans? Obviously not, since it would take many decades.
Some pointers for further reading:
This is a pretty fantastic writeup, short and simple on each topic with loads of sources.
For those looking for something actionable, you may want to head to the reddit board for intermittent fasting. It's a good way to lower your caloric intake and increase autophagy. People doing intermittent fasting often also eat a keto diet that is mentioned in the writing as well.
The author of this overview, Laura Deming, runs the Longevity Fund, and has a research background in the study of aging. She merits congratulations for being, I think, the first by a few years to put together a longevity-focused fund, now joined by e.g. Jim Mellon's Juvenescence venture, Methuselah Fund, Apollo Ventures, etc.
Rejuvenation research after the SENS Research Foundation model of repairing the known root causes of aging is a massive arbitrage opportunity. It remains the case that most people just don't get it, and are thus enormously undervaluing research and companies in this space. That is changing in senescent cell clearance, but six or seven other nascent areas of research and development are in exactly the same position senescent cell clearance was in back in 2010 - no attention, little funding, low valuation, huge potential for breakout gains in said valuation on producing a technology demonstration for rejuvenation in animal models.
It seems likely that the Longevity Fund will do well on the basis of having invested in Unity Biotechnology alone, even putting aside any other successes. The article linked here is a useful overview, with copious references, of the type of work presently taking place in the aging research community. It well illustrates that, aside from senescent cell clearance, nearly everything that counts as a major interest by funding and number of scientists involved is a form of tinkering with stress response biochemistry to modestly slow aging - not addressing root cause molecular damage by repairing it, but rather messing with metabolism to slow damage accumulation. Nowhere near as helpful.
Given what we know, where the data exists to compare outcomes between short-lived and long-lived species, the approach of altering metabolic processes to enhance beneficial stress response mechanisms is not going to move the needle all that far in humans. The results should be exercise-like and calorie-restriction-like in that they have worthwhile effects on long-term health, assuming that the cost of development and treatment is low, but they won't add much more to life expectancy than those two items are capable of achieving - which means perhaps the low end of five to ten years at best in our species, assuming life-long commitment to the intervention. Given that senescent cell clearance is a going concern, and other damage repair approaches such as cross-link breaking should follow in the years ahead, we can hope that the focus of the research community will shift as other approaches prove themselves much more cost-effective and successful.
Very interesting research, but trying to derive actionable recommendations for humans seems a bit laughable at this point. Still seems tough to become immortal these days. Harvesting young blood, a rigid diet, castration and starving yourself occasionally - lots of effort your self-absorbed wealthy investor with a desire to live forever has to go through.
But then again, Sam Altman recently praised China for having fewer ethical concerns in that regard, so maybe they will get some longitudinal human studies going. The population scale full-genome analyses that are currently underway might also be helpful.
This is an awesome write-up.
Regarding the experiment on monkeys that showed calorie restriction led to a longer life, there is one key point that I think damages the conclussion. Both groups of monkeys were fed an extremely unhealthy diet that was very high in sugar. So the conclusion would be that eating fewer unhealthy calories leads to a longer life, not that calorie restriction in itself does.
"long" interview with aubrey de grey from last december:
Very interesting and informative! As someone who knows nothing about this field, this was a really great summary! (I can only assume it's accurate unless someone chimes in to claim otherwise).
You guys should look at the "steak and eggs" diet. This is the best diet I did. You loose a lot of weight, feel amazing, no brain fog, you do not get crazy hungry. It's amazing!
Yes this is a great introduction into the topic. I would also recommend checking out www.leafscience.org home of the LEAF foundation. They are the guys who did that great video with Kurzgesagt last year and their website is packed with great info about aging and research.
Really well written article! And a lot of things I've never heard of.
While keto is mentioned, I do think that another diet deserves a mention here: WFPB (whole food plant based).
In the book, How Not To Die, Dr Greger bring together the science that underpins this diet. Some one switching to this from a standard american diet can expect to add some healthy years to their lives, based on sci evidence.
Thanks everyone for reading! I'll be around if you have any questions.
I recommend Peter Attia's highly engaging and informative talk  on the same topic, which I think does a better job at articulating the motivation behind possible approaches to attacking the issue of health- and life-span.
It would be interesting to see a lab focussed on reproducing these findings and then running all the various combinations to see how those incremental improvements stack. Seems like something we should get ahead of before people run into unknown consequences of trying their own combinations.
That table at the end has a column "Median Lifespan Increase (treated/control)". No, it isn't an increase, it is a ratio.
Eg, the first entry, scenescent cell removal %135, is a 35% increase, not a 135% increase.
Dr. Greger's talk is excellent with respect to how diet can influence longevity.
You may enjoy Dr Rhonda Patrick's podcast as well.
I know they're for illustrative purposes but I really would have appreciated some scales on those graphs.
Almost all animal testing is done on animals that manufacture L-Ascorbic Acid in their liver. L-Ascorbic Acid is an incredibly powerful hormone and completely discounting it's presence is foolish at best and negligent at worst.
I'm a bit surprised at no mention of importance of sleep. Why is that?
Or is this because that falls outside of scope of what "longevity research" in this case means?
if you are interested in the biopharma industry in general, in addition to the sources she lists on her site, here is a primer i recently put together: http://newbio.tech/blog.html
Why starve yourself by calorie restriction for 30 years when some bozo will shoot you dead in the end .
What's the end game here? A future ruled by 400 year old Zuckerbergs and other multi-trillionaires?
Much of the progress in society is possible only because previous generations eventually die off. What happens when that's no longer the case?