Strikingloo

Longevity

Here goes anything interesting relating to longevity. Especially actionable advice.

Blue Zones

Source: Blue Zones - National Library of Medicine.

The Danish Twin Study established that only about 20% of how long the average person lives is dictated by our genes, whereas the other 80% is dictated by our lifestyle.

The 5 demographically confirmed, geographically defined areas (called Blue Zones) with the highest percentage of centenarians are:

In those areas, people reach age 100 at 10 times greater rates than in the United States.

lifestyles of all Blue Zones residents shared 9 specific characteristics. These are called the Power 9.

To make it to age 100, it seems that a person must have to win the genetic lottery. However, many individuals have the capacity to make it well into the early 90s and largely without chronic disease. Blue Zones uncovered 9 evidence-based common denominators among the world’s centenarians that are believed to slow this aging process.

Power 9

The other two are Wine & Religion (which I will assume have more to do with correlation than causation, though religion may help in the right tribe, move and purpose components).

Some actionable advice mentioned in the article: putting a bowl of fruit on the counter, serving food at the stove and not on the table, using hand tools for yard work, and many more. Policy goals would include encouraging fruit and vegetables consumption and walking, and discourage candy and fast food consumption.

Advice on Longevity from LessWrong

Taken from a post by @RomeoStevens.

“Exercise is probably the single most important lifestyle intervention. Even minimal amounts of exercise have very large impacts on longevity and health. We’re talking even walking 15 minutes a day causing people to live longer. Even ignoring quality of life you are looking at a 3-7 fold return on every minute you spend exercising in extended life, perhaps even exceeding that if you are making optimal use of your time. Exercise has a positive impact on pretty much everything that contributes to mortality.”

“Exercise has a protective effect against exactly the sorts of degenerative injuries that deprive people of their freedom of movement and activity.”

Exercise should include resistance training and cardio.

Immunosenescence

From [Nintil on immunosenescence][https://nintil.com/immunosenescence] (emphasis mine).

There seem to be some root causes: Some are damage related (In HSCs and potentially tissue-resident macrophages), others are programmed (involution of various tissues [the thymus being of special importance]). It may well be that addressing the programmed causes also fixes the damage ones, depending on how much do intrinsic vs extrinsic factors matter for immunosenescence, a debate that remains unsettled.

Second, is the importance of intercellular signaling: Cells may be okay but act old if surrounded by old cells. Therapeutically, this suggests that you would need to replace the entire microenvironment of the cell for the greatest impact. In the same way that the most rapid way to change culture is rapidly replace the people that embody that culture, the fastest way to get old cells to act young is to rejuvenate a large amount of them, simultaneously. Rejuvenating just the thymus or just engrafting some young HSCs will not be enough.

Fourth is the incredible diversity there is in the immune system (…)
This diversity extends across species: mice immune system dynamics are not like those of humans.

He emphasizes many important questions remain unanswered (there is always conflicting evidence), thymus rejuvenation may be a good therapy but insufficient, and the mechanisms that regulate e.g. programmed degeneration of the thymus are extremely complex and not yet well understood. Basic research in these kinds of mechanisms still presents a lot of uncharted territory.

It is fine if the degradation of function has no free-standing root cause and instead is a convoluted mesh of feedback loops, with no key players, but still identifying them and being able to treat all of them at once in vivo should lead to faster progress in reverting immunosenescence.

I expect progress in this area to remain “slow” (no appreciable changes for non-experts) for the short term.

How to make an old immune system young again

New research published in Nature this week found that reducing certain stem cells in old mice can rejuvenate their immune systems, making them more effective at fighting viral infections and reducing inflammation. This works by rebalancing the types of stem cells that affect immune responses, shifting them from those that cause inflammation to those that support a more youthful immune function. We’re still years away from going from mice to men, but the research’s findings could help improve aging immune systems.
Heidi Ledford, Nature

Lunges as superior alternative to normal walking

The intervention period was 12 weeks. It consisted of four weeks of normal walking followed by eight weeks of eccentric walking.

The number of eccentric steps in the eccentric walking period gradually increased over eight weeks from 100 to 1,000 steps (including lunges, downhill and downstairs steps). Participants took a total of 3,900 eccentric steps over the eight-week eccentric walking period while the total number of steps was the same as the previous four weeks.

We found no significant changes in any of the outcomes in the first four weeks when participants walked conventionally.

From week four to 12, we found significant improvements in muscle strength (19%), chair-stand ability (24%), balance (45%) and a cognitive function test (21%).

Serum C1q concentration decreased by 10% after the eccentric walking intervention, indicating participants’ muscles were effectively stimulated.

Summary: Because it exerts the muscles and makes them stretch more, eccentric walking (both artificially by adding lunges, or naturally when walking uphill or downhill) seems to be much better at preserving or increasing muscle strength. Worth taking into account for daily walks. Await studies with bigger N (in this case N=11).

Source: Effects of lunges inserted in walking (eccentric walking) on lower limb muscle strength, physical and cognitive function of regular walkers, Yoshihiro Katsura et al.

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19 Jul 2022 - importance: 5