aging

All posts tagged aging

Book review: Lifespan: Why We Age – and Why We Don’t Have To, by David A. Sinclair.

A decade ago, the belief that aging could be cured was just barely starting to get attention from mainstream science, and the main arguments for a cure came from people with somewhat marginal formal credentials.

Now we have a book by an author who’s a co-chief editor of the scientific journal Aging. He’s the cofounder of 14 biotech companies (i.e. probably more than he’s had enough time to work for full time, so I’m guessing some companies are listing him as a cofounder more for prestige than for full-time work). He’s even respected enough by some supplement companies that they use his name, even after he sends them cease and desist letters.

I’m glad that Sinclair published a book that says aging can be cured, since there’s still a shortage of eminent scientists who are willing to take that position.

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I’ve mentioned Blue Zones approvingly several times on this blog (here, here, and here).

Alas, there are reasons to doubt that they’re unusually healthy. The paper Supercentenarians and the oldest-old are concentrated into regions with no birth certificates and short lifespans makes a decent case that they’re mostly just areas where ages have been overstated. There are some relatively unhelpful arguments about who’s right on Andrew Gelman’s blog and on Bluezones.com.

As a consequence, I’m slightly decreasing my opinion of some foods that I was encouraged to eat by the Blue Zone memes: whole grains, beans, olive oil, and sweet potatoes. Sweet potatoes still seem likely to be quite healthy compared to the average American food, but I’m now uncertain whether they’re better or worse than the average paleo food (I previously considered them one of the best foods available). The rest of those foods seem no worse than the average American food, but I’m less optimistic about the safety of the average American food than I previously was.

I’ve also become less confident in the safety of a diet with less than 10% of calories from protein (Blue Zone Okinawans in 1949 got 9% of calories from protein), but I’d already decided not to pursue a low protein diet.

I’ve slightly decreased my opinion of Steven Gundry and Valter Longo

H/T William Eden.

Book review: The Longevity Diet: Discover the New Science Behind Stem Cell Activation and Regeneration to Slow Aging, Fight Disease, and Optimize Weight, by Valter Longo.

Longo is a moderately competent researcher whose ideas about nutrition and fasting are mostly heading in the right general direction, but many of his details look suspicious.

He convinced me to become more serious about occasional, longer fasts, but I probably won’t use his products.
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Book review: Tripping over the Truth: the Return of the Metabolic Theory of Cancer Illuminates a New and Hopeful Path to a Cure, by Travis Christofferson.

This book is mostly a history of cancer research, focusing on competing grand theories, and the treatments suggested by the author’s preferred theory. That’s a simple theory where the prime cause of cancer is a switch to fermentation (known as the metabolic theory, or the Warburg hypothesis).

He describes in detail two promising treatments that were inspired by this theory: a drug based on 3-bromopyruvate (3BP), and a ketogenic diet.

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Book(?) review: Microbial Burden: A Major Cause Of Aging And Age-Related Disease, by Michael Lustgarten.

This minibook has highly variable quality.

Lustgarten demonstrates clear associations between microbes and aging. That’s hardly newsworthy.

He’s much less clear when he switches to talking about causality. He says microbes are the root cause of aging, and occasionally provides weak evidence to support that.

I still have plenty of reason to suspect that much of those associations are due to frailty and declining immune systems, which let microbes take over more. Lustgarten doesn’t make the kind of argument that would convince me that the microbe –> senility causal path is more important than the senility –> microbe causal path.

He has a decent amount of practical advice that is likely to be quite healthy even if he’s wrong about the root cause of aging, including: eat lots of leaves, green peppers, mushrooms, and use low pH soap.

One confusing recommendation is to limit our protein intake to moderate levels.

He provides a nice graph of mortality as a function of BUN (see here for more evidence about BUN), which hints that we should reduce BUN by reducing protein intake.

He also notes that methionine restriction has significant evidence behind it, and methionine restriction requires restricting protein, especially animal proteins.

Yet I see some suggestions that protein (methionine) restriction is likely only helpful in people with kidney disease.

My impression is that high BUN mostly indicates poor health when it’s caused by kidney problems, and doesn’t provide much reason for reducing protein consumption, and least in people with healthy kidneys.

Lustgarten has since blogged about evidence (see the 7/11/2018 update) that higher protein intake helps reduce his homocysteine.

I have also noticed a (noisy) negative correlation between my protein consumption and my homocysteine levels. But that might be due to riboflavin – when I reduce my protein intake, I also reduce my riboflavin intake, since crickets are an important source of riboflavin for me. So I want to do more research into dietary protein before deciding to reduce it.

The book is too quick to dive into technical references, with limited descriptions of why they’re relevant. In many cases, I decided they provided only marginal support to his important points.

Read his blog before deciding whether to read the minibook. The blog focuses more on quantified-self-style reporting, and less on promoting a grand theory.

I wrote this post to try to clarify my thoughts about donating to the Longevity Research Institute (LRI).

Much of that thought involves asking: is there a better approach to cures for aging? Will a better aging-related charity be created soon?

I started to turn this post into an overview of all approaches to curing aging, but I saw that would sidetrack me into doing too much research, so I’ve ended up skimping on some.

I’ve ordered the various approaches that I mention from most directly focused on the underlying causes of aging, to most focused on mitigating the symptoms.

I’ve been less careful than usual to distinguish my intuitions from solid research. I’m mainly trying here to summarize lots of information that I’ve accumulated over the years, and I’m not trying to do new research.
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I got interested in trying ashwagandha due to The End of Alzheimer’s. That book also caused me to wonder whether I should optimize my thyroid hormone levels. And one of the many features of ashwagandha is that it improves thyroid levels, at least in hypothyroid people – I found conflicting reports about what it does to hyperthyroid people.

I had plenty of evidence that my thyroid levels were lower than optimal, e.g. TSH levels measured at 2.58 in 2012, 4.69 in 2013, and 4.09 this fall [1]. And since starting alternate day calorie restriction, I saw increasing hypothyroid symptoms: on calorie restriction days my feet felt much colder around bedtime, my pulse probably slowed a bit, my body burned fewer calories, and I got vague impressions of having less energy. Presumably my body was lowering my thyroid levels to keep my weight from dropping.

I researched the standard treatments for hypothyroidism, but was discouraged by the extent of disagreement among doctors about the wisdom of treating hypothyroidism when it’s as mild as mine was. It seems like mainstream medical opinion says the risks slightly outweigh the rewards, and a sizable minority of doctors, relying on more subjective evidence, say the rewards are large, and don’t say much about the risks. Plus, the evidence for optimal thyroid levels protecting against Alzheimer’s seems to come mainly from correlations that are seen only in women.

Also, the standard treatments for hypothyroidism require a prescription (probably for somewhat good reasons), which may have deterred me by more than a rational amount.

So I decided to procrastinate any attempt to optimize my thyroid hormones, and since I planned to try ashwagandha and DHEA for other reasons, I hoped to get some evidence from the small increases to thyroid hormones that I expected from those two supplements.

I decided to try ashwagandha first, due mainly to the large number of problems it may improve – anxiety, inflammation, stress, telomeres, cholesterol, etc.
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Book review: The End of Alzheimer’s, by Dale E. Bredesen.

Alzheimer’s can be at least postponed for years in most people, and maybe fully cured.

The main catches: It only works if started early enough (and Bredesen only has crude guesses about what’s early enough), the evidence is less rigorous than I’d like, and it’s not a medical treatment, it’s a quantified self approach on steroids ketones.

My guess is that the book is roughly 70% correct. If so, that’s an enormous advance.
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Book review: Other Minds: The Octopus, the Sea, and the Deep Origins of Consciousness, by Peter Godfrey-Smith.

This book describes some interesting mysteries, but provides little help at solving them.

It provides some pieces of a long-term perspective on the evolution of intelligence.

Cephalopods’ most recent common ancestor with vertebrates lived way back before the Cambrian explosion. Nervous systems back then were primitive enough that minds didn’t need to react to other minds, and predation was a rare accident, not something animals prepared carefully to cause and avoid.

So cephalopod intelligence evolved rather independently from most of the minds we observe. We could learn something about alien minds by understanding them.

Intelligence may even have evolved more than once in cephalopods – nobody seems to know whether octopuses evolved intelligence separately from squids/cuttlefish.

An octopus has a much less centralized mind than vertebrates do. Does an octopus have a concept of self? The book presents evidence that octopuses sometimes seem to think of their arms as parts of their self, yet hints that their concept of self is a good deal weaker than in humans, and maybe the octopus treats its arms as semi-autonomous entities.

2.

Does an octopus have color vision? Not via its photoreceptors the way many vertebrates do. Simple tests of octopuses’ ability to discriminate color also say no.

Yet octopuses clearly change color to camouflage themselves. They also change color in ways that suggest they’re communicating via a visual language. But to whom?

One speculative guess is that the color-producing parts act as color filters, with monochrome photoreceptors in the skin evaluating the color of the incoming light by how much the light is attenuated by the filters. So they “see” color with their skin, but not their eyes.

That would still leave plenty of mystery about what they’re communicating.

3.

The author’s understanding of aging implies that few organisms die of aging in the wild. He sees evidence in Octopuses that conflicts with this prediction, yet that doesn’t alert him to the growing evidence of problems with the standard theories of aging.

He says octopuses are subject to much predation. Why doesn’t this cause them to be scared of humans? He has surprising anecdotes of octopuses treating humans as friends, e.g. grabbing one and leading him on a ten-minute “tour”.

He mentions possible REM sleep in cuttlefish. That would almost certainly have evolved independently from vertebrate REM sleep, which must indicate something important.

I found the book moderately entertaining, but I was underwhelmed by the author’s expertise. The subtitle’s reference to “the Deep Origins of Consciousness” led me to expect more than I got.