What drives cellular aging?

This 2019 US/UK human cell study by the founder of the epigenetic clock method investigated epigenetic aging:

“It is widely assumed that extension of lifespan is a result of retardation of ageing. While there is no counter-evidence to challenge this highly intuitive association, supporting empirical evidence to confirm it is not easy to acquire.

The scarcity of empirical evidence is due in part to the lack of a good measure of age that is not based on time. In this regard, the relatively recent development of epigenetic clocks is of great interest.

At the cellular level more is known, but from the perspective of what epigenetic ageing is not, rather than what it is. While we still do not know what cellular feature is associated with epigenetic ageing, we can now remove:

  • somatic cell differentiation

from the list of possibilities and place it with

  • cellular senescence,
  • proliferation and
  • telomere length maintenance,

which represent cellular features that are all not linked to epigenetic ageing.”


The study used several agents, including rapamycin, to investigate the hypotheses. Rapamycin isn’t a panacea, but:

“The ability of rapamycin to suppress the progression of epigenetic ageing is very encouraging for many reasons not least because it provides a valuable point-of-entry into molecular pathways that are potentially associated with it. Evidently, the target of rapamycin, the mTOR complex is of particular interest.

The convergence of the GWAS observation with the experimental system described here is a testament of the strength of the skin & blood clock in uncovering biological features that are consistent between the human level and cellular level. It lends weight to the emerging view that the mTOR pathway may be the underlying mechanism that supports epigenetic ageing.”

The limitation section ended with:

“It is important to note that it is inadvisable (actively discouraged) to directly extrapolate the studies here, especially in terms of the magnitude of age suppression, to potential effects of rapamycin on humans.”

https://www.aging-us.com/article/101976/text “Rapamycin retards epigenetic ageing of keratinocytes independently of its effects on replicative senescence, proliferation and differentiation”

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Do delusions have therapeutic value?

This 2019 UK review discussed delusions, aka false beliefs about reality:

“Delusions are characterized by their behavioral manifestations and defined as irrational beliefs that compromise good functioning. In this overview paper, we ask whether delusions can be adaptive notwithstanding their negative features.

We consider different types of delusions and different ways in which they can be considered as adaptive: psychologically (e.g., by increasing wellbeing, purpose in life, intrapsychic coherence, or good functioning) and biologically (e.g., by enhancing genetic fitness).”


1) Although the review section 4 heading was Biological Adaptiveness of Delusions, the reviewers never got around to discussing the evolved roles of brain areas. One mention of evolutionary biology was:

“Delusions are biologically adaptive if, as a response to a crisis of some sort (anomalous perception or overwhelming distress), they enhance a person’s chances of reproductive success and survival by conferring systematic biological benefits.”

2) Although section 5’s heading was Psychological Adaptiveness of Delusions, the reviewers didn’t connect feelings and survival sensations as origins of beliefs (delusions) and behaviors. They had a few examples of feelings:

“Delusions of reference and delusions of grandeur can make the person feel important and worthy of admiration.”

and occasionally sniffed a clue:

“Some delusions (especially so‐called motivated delusions) play a defensive function, representing the world as the person would like it to be.”

where “motivated delusions” were later deemed in the Conclusion section to be a:

“Response to negative emotions that could otherwise become overwhelming.”

3) Feelings weren’t extensively discussed until section 6 Delusions in OCD and MDD, which gave readers the impression that feelings were best associated with those diseases.

4) In the Introduction, sections 4, 5, and 7 How Do We Establish and Measure Adaptiveness, the reviewers discussed feeling meaning in life, but without understanding:

  1. Feelings = meaning in life, as I quoted Dr. Arthur Janov in The pain societies instill into children:

    “Without feeling, life becomes empty and sterile. It, above all, loses its meaning.

  2. Beliefs (delusions) defend against feelings.
  3. Consequentially, the stronger and more numerous beliefs (delusions) a person has, the less they feel meaning in life.

5) Where, when, why, and how do beliefs (delusions) arise? Where, when, why, and how does a person sense and feel, and what are the connections with beliefs (delusions)?

The word “sense” was used 29 times in contexts such as “make sense” and “sense of [anxiety, coherence, control, meaning, purpose, rational agency, reality, self, uncertainty]” but no framework connected biological sensing to delusions. Papers from other fields have detailed cause-and-effect explanations and diagrams for every step of precursor-successor processes.


Regarding the therapeutic value of someone else’s opinion of a patient’s delusions – I’ll reuse this quotation from the Scientific evidence page of Dr. Janov’s 2011 book “Life Before Birth: The Hidden Script that Rules Our Lives” p.166:

“Primal Therapy differs from other forms of treatment in that the patient is himself a therapist of sorts. Equipped with the insights of his history, he learns how to access himself and how to feel.

The therapist does not heal him; the therapist is only the catalyst allowing the healing forces to take place. The patient has the power to heal himself.

Another way Dr. Janov wrote this was on p.58 of his 2016 book Beyond Belief as quoted in Beyond Belief: The impact of merciless beatings on beliefs:

No one has the answer to life’s questions but you. How you should lead your life depends on you, not outside counsel.

We do not direct patients, nor dispense wisdom upon them. We have only to put them in touch with themselves; the rest is up to them.

Everything the patient has to learn already resides inside. The patient can make herself conscious. No one else can.”

https://onlinelibrary.wiley.com/doi/full/10.1002/wcs.1502 “Are clinical delusions adaptive?”

Another important transgenerational epigenetic inheritance study

This 2019 Washington State University rodent study from Dr. Michael Skinner’s lab found:

“A cascade of epigenetic alterations initiated in the PGCs [primordial germ cells] appears to be required to alter the epigenetic programming during spermatogenesis to modify the sperm epigenome involved in the transgenerational epigenetic inheritance phenomenon.

Following fertilization there is a DNA methylation erasure to generate the stem cells in the early embryo, which then remethylate in a cell type-specific manner. The DNA methylation erasure is thought to, in part, reset deleterious epigenetics in the germline. However, imprinted gene DNA methylation sites and induced transgenerational epimutations appear to be protected from this DNA methylation erasure.

A germline with an altered epigenome has the capacity to alter the early embryo’s stem cell’s epigenome and transcriptome that can subsequently impact the epigenomes and transcriptomes of all derived somatic cells. Therefore, an altered sperm epigenome has the capacity to transmit phenotypes transgenerationally. Experiments have demonstrated that epigenetic inheritance can also be transmitted through the female germline.

Previously, the agricultural fungicide vinclozolin was found to promote the transgenerational inheritance of sperm differential DNA methylation regions (DMRs) termed epimutations that help mediate this epigenetic inheritance. The current study was designed to investigate the developmental origins of the transgenerational DMRs during gametogenesis.

The current study with vinclozolin-induced transgenerational inheritance demonstrates that sperm DMRs also originate during both spermatogenesis and earlier stages of germline development, but at distinct developmental stages. This is a genome-wide analysis of epigenetic programming during gametogenesis for transgenerational sperm epimutations.”


The study’s main hypotheses were:

Following fertilization, the hypothesis is that the transgenerational epimutations modify early embryonic transcriptomes and epigenomes to re-establish the cascade for the next generation.

As the individual develops, all somatic cells have altered epigenomes and transcriptomes to promote disease susceptibility later in life.

Researchers: adopt these hypotheses, and don’t limit your study designs to the F1 children as did:

Don’t stop at the F2 grandchildren like:

Continue studies on to F3 descendants who had no direct exposure to the altering stimulus. Keep in the forefront of your research proposals that there are probably more than 10,000,000 F3 great-grandchildren of DES-exposed women just in the US.

https://www.tandfonline.com/doi/pdf/10.1080/15592294.2019.1614417?needAccess=true “Transgenerational sperm DNA methylation epimutation developmental origins following ancestral vinclozolin exposure”

Non-emotional memories

This 2019 US review covered memory mechanisms:

“With memory encoding reliant on persistent changes in the properties of synapses, a key question is how can memories be maintained from days to months or a lifetime given molecular turnover? It is likely that positive feedback loops are necessary to persistently maintain the strength of synapses that participate in encoding.

These levels are not isolated, but linked by shared components of feedback loops.”


Despite the review’s exhaustive discussion, the reviewers never came to the point. The word cloud I made of the review’s most frequent thirty words had little to do with why memory occurs.

Why do some stimuli evoke a memory in response? Why are almost all of the stimuli an organism receives not remembered?

Much of the discussion was baseless because it excluded emotion. Many of the citations’ memory findings relied on emotion, though. For example, in the subsection Roles of persistent epigenetic modifications for maintaining LTF [long-term facilitation], LTP [long-term potentiation], and LTM [long-term memory]:

  • Histone acetylation is increased after fear conditioning in the hippocampus and amygdala.
  • Correspondingly, inhibition of histone deacetylase enhances fear conditioning and LTP.
  • Following fear conditioning, histone phosphorylation is also increased.
  • DNA methylation is also up-regulated in the hippocampus and amygdala after fear conditioning, and inhibition of DNA methylation blocks fear LTM.”

http://learnmem.cshlp.org/content/26/5/133.full “How can memories last for days, years, or a lifetime? Proposed mechanisms for maintaining synaptic potentiation and memory”

Statistical inferences vs. biological realities

A 2019 UCLA study introduced a derivative of the epigenetic clock named GrimAge:

“DNAm GrimAge, a linear combination of chronological age, sex, and DNAm-based surrogate biomarkers for seven plasma proteins and smoking pack-years, outperforms all other DNAm-based biomarkers, on a variety of health-related metrics.

An age-adjusted version of DNAm GrimAge, which can be regarded as a new measure of epigenetic age acceleration (AgeAccelGrim), is associated with a host of age-related conditions, lifestyle factors, and clinical biomarkers. Using large scale validation data from three ethnic groups, we demonstrate that AgeAccelGrim stands out among pre-existing epigenetic clocks in terms of its predictive ability for time-to-death, time-to-coronary heart disease, time-to-cancer, its association with computed tomography data for fatty liver/excess fat, and early age at menopause.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6366976/ “DNA methylation GrimAge strongly predicts lifespan and healthspan”


A miserable attempt at reporting the study’s findings included angles of superstition, fear-of-the-future, and suspicion-by-spurious-association:

“The research has already captured the attention of the life insurance industry. After all, a solid death date could mean real savings when it comes to pricing policies.

The hope is that if and when legitimate anti-aging drugs are developed, GrimAge could be used to test their effectiveness. In a world with functional anti-aging drugs, “doctors could test [your GrimAge number] and say, ‘You know what, you’re aging too quickly. Take this,'” Horvath said.”

https://onezero.medium.com/a-new-test-predicts-when-youll-die-give-or-take-a-few-years-2d08147c8ea6 “A New Test Predicts When You’ll Die (Give or Take a Few Years)”


A detailed blog post from Josh Mitteldorf provided scientific coverage of the study:

“Methylation sites associated with smoking history predicted how long the person would live more accurately than the smoking history itself. Even stranger, the methylation marks most closely associated with smoking were found to be a powerful indication of future health even when the sample was confined to non-smokers.

The DNAm GrimAge clock was developed in two stages, a correlation of a correlation. Curiously, the indirect computation yields the better result.

Horvath’s finding that secondary methylation indicators are more accurate than the underlying primary indicator from which they were derived is provocative, and calls out for a new understanding.”

https://joshmitteldorf.scienceblog.com/2019/03/05/dnam-grimage-the-newest-methylation-clock “DNAm GrimAge—the Newest Methylation Clock”


When there are logical disconnects in findings like the above, it’s time to examine underlying premises. As noted in Group statistics don’t necessarily describe an individual, an assumption required by statistical analyses is that each measured item in the sample is interchangeable with the next.

This presumption is often false, producing individually inapplicable results. For example, Immune memory vs. immune adaptation included this description of the adaptive immune system:

“To be effective, highly specific immune response requires huge diversity of receptors and antibodies, which is achieved by somatic rearrangement of gene segments. Recombination results in millions of TCR [T cell receptor] and antibody variants able to recognize and neutralize millions of various antigens.”

Standard statistics of millions of T cell receptor and antibody variants won’t represent their individually unique properties. Individual differences are their purpose and benefit to us.

The GrimAge study’s overreach was most apparent in stratifying educational attainment to develop correlations. As mentioned in Does a societal mandate cause DNA methylation? such statistics are poor evidence of each individual’s biological realities.

Neither derivatives of group statistics, nor correlations of correlations, seem to be the techniques needed to understand biological causes of effects. Commentators on the GrimAge study mentioned but glossed over this point:

“It remains a mystery why exactly the epigenetic clocks work, and whether age-related changes in DNA methylation contribute to the cause of aging or are a result of it.”

Immune memory vs. immune adaptation

This 2019 Dutch/German/Romanian perspective aimed for a better understanding of immune systems:

“Based on molecular, immunological, and evolutionary arguments, we propose that innate immune memory is a primitive form of immune memory present in all living organisms, while adaptive immune memory is an advanced form of immune memory representing an evolutionary innovation in vertebrates.

Innate immune responses have the capacity to be trained and thereby exert a new type of immunological memory upon reinfection. The central feature of trained innate immune cells is the ability to mount a qualitatively and quantitatively different transcriptional response when challenged with microbes or danger signals. Evidence supports the convergence of multiple regulatory layers for mediating innate immune memory, including changes in chromatin organization, DNA methylation, and probably non-coding RNAs such as microRNAs and/or long non-coding RNAs.

Two properties of the adaptive immune response are mediated by two fundamentally different types of mechanisms:

  1. The higher magnitude and speed of the response is mediated by epigenetic programming.
  2. The specificity of the response is insured by gene recombination of TCR [T cell receptor] and BCR [B cell receptor] and clonal expansion of specific cell subpopulations upon antigen recognition.

To be effective, highly specific immune response requires huge diversity of receptors and antibodies, which is achieved by somatic rearrangement of gene segments. Recombination results in millions of TCR and antibody variants able to recognize and neutralize millions of various antigens.”


The paper included speculations such as the “Evidence supports..probably non-coding RNAs” quoted above, and the penultimate sentence:

“One can envision that vaccines that are capable of inducing both forms of immune memory at the same time would be more effective.”

100% factual evidence is preferred. The paper’s overall information can only be as accurate as the paper’s least accurate information.

The lead author coauthored A dietary supplement that trains the innate immune system and a study referenced in Eat your oats.

https://www.sciencedirect.com/science/article/pii/S1931312818306334 “Innate and Adaptive Immune Memory: an Evolutionary Continuum in the Host’s Response to Pathogens” (not freely available)

Our brains are shaped by our early environments

This 2019 McGill paper reviewed human and animal studies on brain-shaping influences from the fetal period through childhood:

“In neonates, regions of the methylome that are highly variable across individuals are explained by the genotype alone in 25 percent of cases. The best explanation for 75 percent of variably methylated regions is the interaction of genotype with different in utero environments.

A meta-analysis including 45,821 individuals with attention-deficit/hyperactivity disorder and 9,207,363 controls suggests that conditions such as preeclampsia, Apgar score lower than 7 at 5 minutes, breech/transverse presentations, and prolapsed/nuchal cord – all of which involve some sort of poor oxygenation during delivery – are significantly associated with attention-deficit/hyperactivity disorder. The dopaminergic system seems to be one of the brain systems most affected by perinatal hypoxia-ischemia.

Exposure to childhood trauma activates the stress response systems and dysregulates serotonin transmission that can adversely impact brain development. Smaller cerebral, cerebellar, prefrontal cortex, and corpus callosum volumes were reported in maltreated young people as well as reduced hippocampal activity.

Environmental enrichment has a series of beneficial effects associated with neuroplasticity mechanisms, increasing hippocampal volume, and enhancing dorsal dentate gyrus-specific differences in gene expression. Environmental enrichment after prenatal stress decreases depressive-like behaviors and fear, and improves cognitive deficits.”


The reviewers presented strong evidence until the Possible Factors for Reversibility section, which ended with the assertion:

“All these positive environmental experiences mentioned in this section could counterbalance the detrimental effects of early life adversities, making individuals resilient to brain alterations and development of later psychopathology.”

The review’s penultimate sentence recognized that research is seldom done on direct treatments of causes:

“The cross-sectional nature of most epigenetic studies and the tissue specificity of the epigenetic changes are still challenges.”

Cross-sectional studies won’t provide definitive data on cause-and-effect relationships.

The question that remains to be examined is: How can humans best address these early-life causes to ameliorate their lifelong effects?

https://onlinelibrary.wiley.com/doi/full/10.1111/dmcn.14182 “Early environmental influences on the development of children’s brain structure and function” (not freely available)