Gut microbiota and aging

This 2020 review explored the title subject:

“The human body contains 1013 human cells and 1014 commensal microbiota. Gut microbiota play vital roles in human development, physiology, immunity, and nutrition.

Human lifespan was thought to be determined by the combined influence of genetic, epigenetic, and environmental factors including lifestyle-associated factors such as exercise or diet. The role of symbiotic microorganisms has been ignored.

Age-associated alterations in composition, diversity, and functional features of gut microbiota are closely correlated with an age-related decline in immune system functioning (immunosenescence) and low-grade chronic inflammation (inflammaging). Immunosenescence and inflammaging do not have a unidirectional relationship. They exist in a mutually maintained state where immunosenescence is induced by inflammaging and vice versa.

Immunosenescence changes result in both quantitative and qualitative modifications of specific cellular subpopulations such as T cells, macrophages and natural killer cells as opposed to a global deterioration of the immune system. Neutrophils and macrophages from aged hosts are less active with diminished phagocytosing capability.

Gut microbiota transform environmental signals and dietary molecules into signaling metabolites to communicate with different organs and tissues in the host, mediating inflammation. Gut microbiota modulations via dietary or probiotics are useful anti-inflammaging and immunosenescence interventions.

The presence of microbiomic clocks in the human body makes noninvasive, accurate lifespan prediction possible. Prior to occurrence of aging-related diseases [shown above], bidirectional interactions between the gut and extraenteric tissue will change.

Correction of accelerated aging-associated gut dysbiosis is beneficial, suggesting a link between aging and gut microbiota that provides a rationale for microbiota-targeted interventions against age-related diseases. However, it is still unclear whether gut microbiota alterations are the cause or consequence of aging, and when and how to modulate gut microbiota to have anti-aging effects remain to be determined.” “Gut microbiota and aging” (not freely available; thanks to Dr. Zongxin Ling for providing a copy)

1. The “Stable phase” predecessor to this review’s subject deserved its own paper:

“After initial exposure and critical transitional windows within 3 years after birth, it is generally agreed that human gut microbiota develops into the typical adult structure and composition that is relatively stable in adults.

gut microbiota by age phenotype

However, the Human Microbiome Project revealed that various factors such as food modernization, vaccines, antibiotics, and taking extreme hygiene measures will reduce human exposure to microbial symbionts and led to shrinkage of the core microbiome, while the reduction in microbiome biodiversity can compromise the human immune system and predispose individuals to several modern diseases.”

2. I looked for the ten germ-free references in the “How germ-free animals help elucidate the mechanisms” section of The gut microbiome: its role in brain health in this review, but didn’t find them cited. Likewise, the five germ-free references in this review weren’t cited in that paper. Good to see a variety of relevant research.

There were a few overlapping research groups with this review’s “Gut-brain axis aging” section, although it covered only AD and PD research.

3. Inflammaging is well-documented, but is chronic inflammation a condition of chronological age?

A twenty-something today who ate highly-processed food all their life could have gut microbiota roughly equivalent to their great-great grandparents’ at advanced ages. Except their ancestors’ conditions may have been byproducts of “an unintended consequence of both developmental programmes and maintenance programmes.

Would gut microbiota be a measure of such a twenty-something’s biological age? Do we wait until they’re 60, and explain their conditions by demographics? What could they do to reset themself back to a chronological-age-appropriate phenotype?

The future of your brain is in your gut right now

A 2020 paper by the author of Sulforaphane: Its “Coming of Age” as a Clinically Relevant Nutraceutical in the Prevention and Treatment of Chronic Disease:

“The gut and brain communicate bidirectionally via several pathways which include:

  1. Neural via the vagus nerve;
  2. Endocrine via the HPA axis;
  3. Neurotransmitters, some of which are synthesized by microbes;
  4. Immune via cytokines; and
  5. Metabolic via microbially generated short-chain fatty acids.

How does nature maintain the gut-microbiome-brain axis? Mechanisms to maintain homeostasis of intestinal epithelial cells and their underlying cells are a key consideration.

The symbiotic relationship that exists between microbiota and the human host is evident when considering nutrient requirements of each. The host provides food for microbes, which consume that food to produce metabolites necessary for health of the host.

Consider function of the human nervous system, not in isolation but in integration with the gastrointestinal ecosystem of the host, in expectation of a favorable impact on human health and behavior.” “Chapter 14 – The gut microbiome: its role in brain health” (not freely available)

Always more questions:

  • What did you put into your gut today?
  • What type of internal environment did it support?
  • What “favorable impact on human health and behavior” do you expect from today’s intake?
  • How will you feel?
  • Will you let evidence guide feeding your gut environment?

See Switch on your Nrf2 signaling pathway for an interview with the author.

How will you feel?

Consider this a partial repost of Moral Fiber:

“We are all self-reproducing bioreactors. We provide an environment for trillions of microbes, most of which cannot survive for long without the food, shelter and a place to breed that we provide.

They inhabit us so thoroughly that not a single tissue in our body is sterile. Our microbiome affects our development, character, mood and health, and we affect it via our diet, medications and mood states.

The microbiome:

  • Affects our thinking and our mood;
  • Influences how we develop;
  • Molds our personalities;
  • Our sociability;
  • Our responses to fear and pain;
  • Our proneness to brain disease; and
  • May be as or more important in these respects than our genetic makeup.

Dysbiosis has become prevalent due to removal of prebiotic fibers from today’s ultra-processed foods. I believe that dietary shift has created a generation of humans less able to sustain or receive love.

They suffer from reduced motivation and lower impulse control. They are more anxious, more depressed, more selfish, more polarized, and therefore more susceptible to the corrosive politics of identity.

Other recent blog posts by Dr. Paul Clayton and team include Skin in The Game and Kenosha Kids.

Image from Thomas Cole : The Consummation, The Course of the Empire (1836) Canvas Gallery Wrapped Giclee Wall Art Print (D4060)

Eat oats today!

This 2020 food chemistry review provided phenolic-compound reasons to eat oats:

“Phenolamides result from the conjugation of hydroxycinnamic acids with amines. These products contain a variety of metabolic, chemical, and functional capabilities due to the large number of possible combinations among the parent compounds.

Of the currently known phenolamides, the most common are avenanthramides (AVAs), which are unique in oats. AVAs possess anti-inflammatory, anti-itch, anti-atherosclerosis, antioxidant, anti-cancer, anti-obesity, anti-fungal, anti-microbial, and neuroprotective properties.

Twenty-nine C-type AVAs have been identified in oats, and twenty-six A-type AVAs.

  • C-type AVAs in commercially available oat products range from 36.49-61.77 mg/kg (fresh weight).
  • A-type AVAs represent approximately 22.5% of total AVA levels in regular oats and 24.7-33.0% in commercial sprouted oats.

Steeping raw groats increased AVA concentrations.”

These reviews were referenced:

“Since publication of these two reviews, a few new studies reported AVAs’ beneficial health effects, mainly related to their anti-inflammatory and anti-cancer activities. AVAs can:

  • Significantly decrease IL-6, IL-8, and MCP-1 in endothelial cells;
  • Inhibit IL-1β- and TNF-α-induced NF-κB activation; as well as
  • Expression of adhesion molecules; and
  • Adhesion of monocytes to endothelial cell monolayer.

In 2020, the first evaluation of anti-inflammation effects of A-type AVAs was published from our own group. Fifteen A-type AVAs from commercial sprouted oat products interacted with lipopolysaccharide-induced nitric oxide production and iNOS expression.

Colloidal oatmeal’s natural components, AVAs, help to restore and maintain skin barrier function. AVAs are safe, well tolerated, and can be effective as adjuvant treatment in atopic dermatitis.

In one mouse model, a C-type AVA was able to mitigate many adverse effects of Alzheimer’s Disease. It restored hippocampal long-term potentiation and synaptic function, enhanced memory function, suppressed pro-inflammatory cytokines TNF-α and IL-6 levels, reduced caspase-3 levels, and increased pS9GSK-3β and IL-10 levels.

AVAs downregulated expression of hTERT and MDR1, pro-survival genes for cancer cells, and COX-2 mRNA and PGE2 levels, known pro-inflammatory markers. AVAs induced apoptosis by activating caspases 8, 3, and 2.” “The Chemistry and Health Benefits of Dietary Phenolamides” (not freely available)

Hadn’t thought about sprouting oats before this paper.

Clearing out the 2020 queue of interesting papers

I’ve partially read these 39 studies and reviews, but haven’t taken time to curate them.

Early Life

  1. Intergenerational Transmission of Cortical Sulcal Patterns from Mothers to their Children (not freely available)
  2. Differences in DNA Methylation Reprogramming Underlie the Sexual Dimorphism of Behavioral Disorder Caused by Prenatal Stress in Rats
  3. Maternal Diabetes Induces Immune Dysfunction in Autistic Offspring Through Oxidative Stress in Hematopoietic Stem Cells
  4. Maternal prenatal depression and epigenetic age deceleration: testing potentially confounding effects of prenatal stress and SSRI use
  5. Maternal trauma and fear history predict BDNF methylation and gene expression in newborns
  6. Adverse childhood experiences, posttraumatic stress, and FKBP5 methylation patterns in postpartum women and their newborn infants (not freely available)
  7. Maternal choline supplementation during the third trimester of pregnancy improves infant information processing speed: a randomized, double‐blind, controlled feeding study
  8. Preterm birth is associated with epigenetic programming of transgenerational hypertension in mice
  9. Epigenetic mechanisms activated by childhood adversity (not freely available)

Epigenetic clocks

  1. GrimAge outperforms other epigenetic clocks in the prediction of age-related clinical phenotypes and all-cause mortality (not freely available)
  2. Epigenetic age is a cell‐intrinsic property in transplanted human hematopoietic cells
  3. An epigenetic clock for human skeletal muscle
  4. Immune epigenetic age in pregnancy and 1 year after birth: Associations with weight change (not freely available)
  5. Vasomotor Symptoms and Accelerated Epigenetic Aging in the Women’s Health Initiative (WHI) (not freely available)
  6. Estimating breast tissue-specific DNA methylation age using next-generation sequencing data


  1. The Intersection of Epigenetics and Metabolism in Trained Immunity (not freely available)
  2. Leptin regulates exon-specific transcription of the Bdnf gene via epigenetic modifications mediated by an AKT/p300 HAT cascade
  3. Transcriptional Regulation of Inflammasomes
  4. Adipose-derived mesenchymal stem cells protect against CMS-induced depression-like behaviors in mice via regulating the Nrf2/HO-1 and TLR4/NF-κB signaling pathways
  5. Serotonin Modulates AhR Activation by Interfering with CYP1A1-Mediated Clearance of AhR Ligands
  6. Repeated stress exposure in mid-adolescence attenuates behavioral, noradrenergic, and epigenetic effects of trauma-like stress in early adult male rats
  7. Double-edged sword: The evolutionary consequences of the epigenetic silencing of transposable elements
  8. Blueprint of human thymopoiesis reveals molecular mechanisms of stage-specific TCR enhancer activation
  9. Statin Treatment-Induced Development of Type 2 Diabetes: From Clinical Evidence to Mechanistic Insights
  10. Rewiring of glucose metabolism defines trained immunity induced by oxidized low-density lipoprotein
  11. Chronic Mild Stress Modified Epigenetic Mechanisms Leading to Accelerated Senescence and Impaired Cognitive Performance in Mice
  12. FKBP5-associated miRNA signature as a putative biomarker for PTSD in recently traumatized individuals
  13. Metabolic and epigenetic regulation of T-cell exhaustion (not freely available)


  1. Molecular and cellular mechanisms of aging in hematopoietic stem cells and their niches
  2. Epigenetic regulation of bone remodeling by natural compounds
  3. Microglial Corpse Clearance: Lessons From Macrophages
  4. Plasma proteomic biomarker signature of age predicts health and life span
  5. Ancestral stress programs sex-specific biological aging trajectories and non-communicable disease risk

Broccoli sprouts

  1. Dietary Indole-3-Carbinol Alleviated Spleen Enlargement, Enhanced IgG Response in C3H/HeN Mice Infected with Citrobacter rodentium
  2. Effects of caffeic acid on epigenetics in the brain of rats with chronic unpredictable mild stress
  3. Effects of sulforaphane in the central nervous system
  4. Thiol antioxidant thioredoxin reductase: A prospective biochemical crossroads between anticancer and antiparasitic treatments of the modern era (not freely available)
  5. Quantification of dicarbonyl compounds in commonly consumed foods and drinks; presentation of a food composition database for dicarbonyls (not freely available)
  6. Sulforaphane Reverses the Amyloid-β Oligomers Induced Depressive-Like Behavior (not freely available)

Dietary contexts matter

Two papers illustrated how actions of food compounds are affected by their contexts. The first was a 2020 UCLA rodent study:

“Long-chain polyunsaturated fatty acids (PUFAs), particularly omega-3 (n-3) PUFAs, have been indicated to play important roles in various aspects of human health. Controversies are observed in epidemiological and experimental studies regarding the benefits or lack of benefits of n-3 PUFAs.

Dietary docosahexaenoic acid (DHA; 22:6 n-3) supplementation improved select metabolic traits and brain function, and induced transcriptomic and epigenetic alterations in hypothalamic and hippocampal tissues in both context-independent and context-specific manners:

  • In terms of serum triglyceride, glycemic phenotypes, insulin resistance index, and memory retention, DHA did not affect these phenotypes significantly when examined on the chow diet background, but significantly improved these phenotypes in fructose-treated animals.
  • Genes and pathways related with tissue structure were affected by DHA regardless of the dietary context, although the direction of changes are not necessarily the same between contexts. These pathways may represent the core functions of DHA in maintaining cell membrane function and cell signaling.
  • DHA affected the mTOR signaling pathway in hippocampus. In the hypothalamus, altered pathways were more related to innate immunity, such as cytokine-cytokine receptors, NF-κB signaling pathway, and Toll-like receptor signaling pathway.

DHA exhibits differential influence on epigenetic loci, genes, pathways, and metabolic and cognitive phenotypes under different dietary contexts.” “Multi‐tissue Multi‐omics Nutrigenomics Indicates Context‐specific Effects of DHA on Rat Brain” (not freely available)

A human equivalent age period of the subjects was 12 to 20 years old. If these researchers want to make their study outstanding, they’ll contact their UCLA colleague Dr. Steven Horvath, and apply his new human-rat relative biological age epigenetic clock per A rejuvenation therapy and sulforaphane.

The second paper was a 2016 review Interactions between phytochemicals from fruits and vegetables: Effects on bioactivities and bioavailability (not freely available):

“The biological activities of food phytochemicals depend upon their bioaccessibility and bioavailability which can be affected by the presence of other food components including other bioactive constituents. For instance, α-tocopherol mixed with a flavonol (kaempferol or myricetin) is more effective in inhibiting lipid oxidation induced by free radicals than each component alone.

Interactions of phytochemicals may enhance or reduce the bioavailability of a given compound, depending on the facilitation/competition for cellular uptake and transportation. For example, β-carotene increases the bioavailability of lycopene in human plasma, and quercetin-3-glucoside reduces the absorption of anthocyanins.

Combinations of food extracts containing hydrophilic antioxidants and lipophilic antioxidants showed very high synergistic effects on free radical scavenging activities. A number of phytochemical mixtures and food combinations provide synergistic effects on inhibiting inflammation.

More research should be conducted to understand mechanisms of bioavailability interference considering physiological concentrations, food matrices, and food processing.”

Each of us can set appropriate contexts for our food consumption. Broccoli sprout synergies covered how I take supplements and broccoli sprouts together an hour or two before meals to keep meal contents from lowering sulforaphane bioavailability.

Combinations of my 19 supplements and broccoli sprouts are too many (616,645) for complete analyses. Just pairwise comparisons like the second paper’s example below would be 190 combinations.

binary isobologram

Contexts for each combination’s synergistic, antagonistic, or additive activities may also be influenced by other combinations’ results.

My consumption of flax oil (alpha linolenic acid C18:3) probably has effects similar to DHA since it’s an omega-3 PUFA and I take it with food. The first study’s human equivalent DHA dose was 100mg/kg, with its citation for clinical trials stating “1–9 g/day (0.45–4% of calories) n-3 PUFA.”

A 2020 review Functional Ingredients From Brassicaceae Species: Overview and Perspectives had perspectives such as:

“In many circumstances, the isolated bioactive is not as bioavailable or metabolically active as in the natural food matrix.”

It discussed categories but not combinations of phenolics, carotenoids, phytoalexins, terpenes, phytosteroids, and tocopherols, along with more well-known broccoli compounds.

Diving for breakfast

Natural sources of melatonin

This 2020 review subject was melatonin:

“The emergence of naturally occurring melatonin and its isomers in fermented foods has opened an exciting new research area. Melatonin is a hormone, an indolamine that predominantly appears in plants, microorganisms, and mammals.

The precursor of this molecule is solely the amino acid L‐tryptophan. Melatonin ensures a circadian and seasonal signal to vertebrate organisms; it is synthesized through a cascade of enzymatic reactions producing melatonin from serotonin in its final phases. The synthesis of melatonin is observed in almost all organs.

One melatonin molecule has the capacity to scavenge up to 10 ROS versus the other antioxidants that scavenge 1 or even less ROS. Melatonin antioxidant properties are accomplished with the indole ring that stimulates enzyme production (i.e., superoxide dismutase (SOD), glutathione‐peroxidase (Gpx), and catalase (CAT)), which mitigate free radicals to less toxic substances.

In addition to antioxidant properties, it plays a fundamental role in the modulation of various physiological functions, including circadian rhythmicity, bone integrity, and functionalization of the human reproductive system.

The presence of melatonin and its isomers is not exclusive for grapes and grape‐derived products. Other fruits such as sweet and sour cherries and fermented juices of orange and pomegranate may be also of interest.” “Naturally occurring melatonin: Sources and possible ways of its biosynthesis”

Treating psychopathological symptoms will somehow resolve causes?

This 2020 Swiss review subject was potential glutathione therapies for stress:

“We examine the available data supporting a role for GSH levels and antioxidant function in the brain in relation to anxiety and stress-related psychopathologies. Several promising compounds could raise GSH levels in the brain by either increasing the availability of its precursors or the expression of GSH-regulating enzymes through activation of Nrf2.

GSH is the main cellular antioxidant found in all mammalian tissues. In the brain, GSH homeostasis has an additional level of complexity in that the expression of GSH and GSH-related enzymes are not evenly distributed across all cell types, requiring the coordination between neurons and astrocytes to neutralize oxidative insults.

Increased energy demand in situations of chronic stress leads to mitochondrial ROS overproduction, oxidative damage and exhaustion of GSH pools in the brain.

Several compounds can function as precursors of GSH by acting as cysteine (Cys) donors such as taurine or glutamate (Glu) donors such as glutamine (Gln). Other compounds stimulate the synthesis and recycling of GSH through the activation of the Nrf2 pathway including sulforaphane and melatonin. Compounds such as acetyl-L-carnitine can increase GSH levels.” “Therapeutic potential of glutathione-enhancers in stress-related psychopathologies” (not freely available)

Many animal studies of “stress-related psychopathologies” were cited without noting applicability to humans. The reviewers instead had curious none-of-this-means-anything disclaimers like:

“Comparisons between studies investigating brain disorders of such different nature such as psychiatric disorders or neurodegenerative diseases, or even between brain or non-brain related disorders should be made with caution.”

Regardless, this paper had informative sections for my 27th week of eating broccoli sprouts every day.

1. I forgot to mention in Broccoli sprout synergies that I’ve taken 500 mg of trimethyl glycine (aka betaine) twice a day for over 15 years. Section 3.1.2 highlighted the amino acid glycine:

“Endogenous synthesis is insufficient to meet metabolic demands for most mammals (including humans) and additional glycine must be obtained from the diet. While most research has focused on increasing cysteine levels in the brain in order to drive GSH synthesis, glycine supplementation alone or in combination with cysteine-enhancing compounds are gaining attention for their ability to enhance GSH.”

2. The amino acid taurine dropped off my supplement regimen last year after taking 500 mg twice a day for years. It’s back on now after reading Section 3.1.3:

“Most studies that reported enhanced GSH in the brain following taurine treatment were performed under a chronic regimen and used in age-related disease models. Such positive effects of taurine on GSH levels may be explained by the fact that cysteine is the essential precursor to both metabolites, whereby taurine supplementation may drive the metabolism of cysteine towards GSH synthesis.

3. A study in Upgrade your brain’s switchboard with broccoli sprouts was cited for its potential:

“Thalamic GSH values significantly correlated with blood GSH levels, suggesting that peripheral GSH levels may be a marker of brain GSH content. Studies point to the capacity of sulforaphane to function both as a prophylactic against stress-induced behavioral changes and as a positive modulator in healthy animals.”

Sunrise minus 5 minutes

Unraveling oxytocin – is it nature’s medicine?

This 2020 review attempted to consolidate thousands of research papers on oxytocin:

“Chemical properties of oxytocin make this molecule difficult to work with and to measure. Effects of oxytocin are context-dependent, sexually dimorphic, and altered by experience. Its relationship to a related hormone, vasopressin, have created challenges for its use as a therapeutic drug.

Widely used medical interventions i.e.:

  • Exogenous oxytocin, such as Pitocin given to facilitate labor;
  • Opioid medications that block the oxytocin system; or
  • Cesarean sections that alter exposure to endogenous oxytocin

have lasting consequences for the offspring and/or mother.

Such exposures hold the potential to have epigenetic effects on the oxytocin systems, including changes in DNA methylation. These changes in turn would have lasting effects on the expression of receptors for oxytocin, leaving individuals differentially able to respond to oxytocin and also possibly to the effects of vasopressin.

Regions with especially high levels of OXTR [oxytocin receptor gene] are:

  • Various parts of the amygdala;
  • Bed nucleus of the stria terminalis;
  • Nucleus accumbens;
  • Brainstem source nuclei for the autonomic nervous system;
  • Systems that regulate the HPA axis; as well as
  • Brainstem tissues involved in pain and social attention.

Oxytocin protects neural cells against hypoxic-ischemic conditions by:

  • Preserving mitochondrial function;
  • Reducing oxidative stress; and
  • Decreasing a chromatin protein that is released during inflammation

which can activate microglia through the receptor for advanced glycation end products (RAGE). RAGE acts as an oxytocin-binding protein facilitating the transport of oxytocin across the blood-brain barrier and through other tissues.

Directionality of this transport is 5–10 times higher from the blood to the brain, in comparison with brain to blood transport. Individual differences in RAGE could help to predict cellular access to oxytocin and might also facilitate access to oxytocin under conditions of stress or illness.

Oxytocin and vasopressin and their receptors are genetically variable, epigenetically regulated, and sensitive to stressors and diet across the lifespan. As one example, salt releases vasopressin and also oxytocin.

Nicotine is a potent regulator of vasopressin. Smoking, including prenatal exposure of a fetus, holds the potential to adjust this system with effects that likely differ between males and females and that may be transgenerational.

Relative concentrations of endogenous oxytocin and vasopressin in plasma were associated with:

These studies support the usefulness of measurements of both oxytocin and vasopressin but leave many empirical questions unresolved.

The vast majority of oxytocin in biosamples evades detection using conventional approaches to measurement.” “Is Oxytocin Nature’s Medicine?”

I appreciated efforts to extract worthwhile oxytocin research from countless poorly performed studies, research that wasted resources, and research that actually detracted from science.

I was disappointed that at least one of the reviewers didn’t take this review as an opportunity to confess their previous wastes like three flimsy studies discussed in Using oxytocin receptor gene methylation to pursue an agenda.

Frank interpretations of one’s own study findings to acknowledge limitations is one way researchers can address items upfront that will be questioned anyway. Such analyses also indicate a goal to advance science.

Although these reviewers didn’t provide concrete answers to many questions, they highlighted promising research areas, such as:

  • Improved approaches to oxytocin measurements;
  • Prenatal epigenetic experience associations with oxytocin and OXTR; and
  • Possible transgenerational transmission of these prenatal epigenetic experiences.

Part 3 of Do broccoli sprouts treat migraines?

This 2019 Swedish review subject was the role of inflammation in migraines:

“In this article, we argue that inflammation could have an important role in migraine chronification through a mechanism termed neurogenic neuroinflammation, a phenomenon whereby activation of trigeminal sensory pathways leads to an orchestrated inflammatory response involving immune cells, vascular cells and neurons.

No studies to date have directly linked hypothalamic neuroinflammation with migraine, and we therefore looked to other studies. Overactivity of the NF-κB–IKKβ signalling pathway has been shown to be a critical modulator of hypothalamic inflammation.

We do not believe that CNS inflammation is involved in the triggering of migraine attacks, as BBB alterations, glial cell activation and leukocyte infiltration have not been observed in individuals with this condition. Peripheral sensitization is an important factor in migraine chronification, as opposed to migraine triggering.” “Does inflammation have a role in migraine?” (not freely available)

See Reevaluate findings in another paradigm for other views of hypothalamic inflammation.

I came across this review through its citation in the 2020 medical paper The fifth cranial nerve in headaches with the same lead author:

“Reduced serotonergic transmission seems to be involved in medication overuse headache development, possibly through a facilitation of the sensitization process via a maladaptive plasticity. In humans, common neurophysiological investigation of central sensitization shows an abnormal cortical response to repetitive sensory stimuli, with an increased response amplitude after low numbers of stimuli and a lacking habituation, suggesting an altered plasticity.

Neurons, under repetitive, persistent nociceptive stimuli, become sensitized and produce exaggerated and prolonged responses to lower threshold stimuli. Over time, a neuroplastic adaptation in medullary and cortical pain areas causes a shift in the pain modulatory system creating a new threshold and favouring a net pain facilitation rather than pain alleviation.

Targets are almost exclusively found in the nerves of trigeminal ganglion; the hub of the fifth cranial nerve. Although we believe that the headache-trigger most likely have the origin in the CNS, this review underscores the importance of trigeminal neurons in the perception of pain.”

This second paper listed various treatments of symptoms. It was remarkable for no focus on treatments of causes.

Per Parts 1 and 2, I rarely get headaches anymore, much less migraines. 23 weeks of eating a clinically relevant amount of broccoli sprouts every day resolved causes for me. I didn’t appreciate how migraines and many other things changed until awakening during Week 9.

Forget about the above papers’ recursively-created hierarchy that permitted systematic self-justifications. Science is neither “We do not believe” nor “we believe that..”

Instead, address migraines by getting rid of inflammation in its many forms, to include:

  • Taking walks, exercising, or physically working every day;
  • Eating foods our great-great grandparents ate;
  • Practicing oral hygiene.

And support those closest to you:

Part 2 of Do broccoli sprouts treat migraines?

To follow up Do broccoli sprouts treat migraines? which used a PubMed “sulforaphane migraine” search, a PubMed “diindolylmethane” search came across a 2020 Czech human cell study Antimigraine Drug Avitriptan Is a Ligand and Agonist of Human Aryl Hydrocarbon Receptor that Induces CYP1A1 in Hepatic and Intestinal Cells that had this informative Introduction:

“The aryl hydrocarbon receptor (AhR) transcriptionally controls a wide array of genes. AhR is a critical player in human physiology (e.g., hematopoiesis) and also in many pathophysiological processes such as diabetes, carcinogenesis, inflammation, infection or cardiovascular diseases.

Suitable candidates for off-targeting AhR could be the antimigraine drugs of triptan class, which have an indole core in their structure. Indole-based compounds were demonstrated as ligands of AhR, including dietary indoles (e.g., indole-3-carbinol and diindolylmethane).”

Adding AhR to the search showed:

Changing the PubMed search to “icz migraine” pulled up a 2013 review Biomedical Importance of Indoles that described sumatriptan as an indole, and:

“Since DIM accumulates in the cell nucleus, it likely contributes to cell nuclear events that have been ascribed to I3C.”

Widening the search to “i3c ahr” added:

Changing the search to “i3c migraine” picked up a 2011 UK human study Effect of diindolylmethane supplementation on low-grade cervical cytological abnormalities: double-blind, randomised, controlled trial:

“In the study reported here, there was no statistically significant difference in serious adverse events between groups; in fact a higher proportion of women in the placebo group reported a serious adverse event. Although this study did not have sufficient power to study migraines, we did find a non-significant increase in reported headaches (18% on DIM, 12% on placebo, P=0.12).”

Returning to the original PubMed “sulforaphane migraine” search, Bioavailability of Sulforaphane Following Ingestion of Glucoraphanin-Rich Broccoli Sprout and Seed Extracts with Active Myrosinase: A Pilot Study of the Effects of Proton Pump Inhibitor Administration included one subject who took migraine medication. They weren’t a study outlier, however.

Although indole chemistry indicates a broccoli sprouts – migraine connection, I haven’t found relevant research. Maybe the known properties and actions of broccoli sprout compounds provide enough to affect causes of migraines?

See Part 3 to follow up.

The epigenetics of perinatal stress

This 2019 McGill review discussed long-lasting effects of perinatal stress:

“Epigenetic processes are involved in embedding the impact of early-life experience in the genome and mediating between social environments and later behavioral phenotypes. Since these phenotypes are apparent a long time after early experience, changes in gene expression programming must be stable.

Although loss of methylation in a promoter is necessary for expression, it is not sufficient. Demethylation removes a barrier for expression, but expression might be realized at the right time or context when needed factors or signals are present.

DNA methylation anticipates future transcriptional response to triggers. Comparing steady-state expression with DNA methylation does not capture the full meaning and scope of regulatory roles of differential methylation.

A model for epigenetic programming by early life stress:

  1. Perinatal stress perceived by the brain triggers release of glucocorticoids (GC) from the adrenal in the mother prenatally or the newborn postnatally.
  2. GC activate nuclear glucocorticoid receptors across the body, which epigenetically program (demethylate) genes that are targets of GR in brain and white blood cells (WBC).
  3. Demethylation events are insufficient for activation of these genes. A brain specific factor (TF) is required for expression and will activate low expression of the gene in the brain but not in blood.
  4. During adulthood a stressful event transiently triggers a very high level of expression of the GR regulated gene specifically in the brain.

Horizontal arrow, transcription; circles, CpG sites; CH3 in circles, methylated sites; empty circles, unmethylated CpG sites; horizon[t]al curved lines, mRNA.”

Review points discussed:

  • “Epigenetic marks are laid down and maintained by enzymes that either add or remove epigenetic modifications and are therefore potentially reversible in contrast to genetic changes.
  • Response to early life stress and maternal behavior is also not limited to the brain and involves at least the immune system as well.
  • The placenta is also impacted by maternal social experience and early life stress.
  • Most studies are limited to peripheral tissues such as saliva and white blood cells, and relevance to brain physiology and pathology is uncertain.
  • Low absolute differences in methylation seen in most human behavioral EWAS raise questions about their biological significance.

  • Although post-mortem studies examine epigenetic programming in physiologically relevant tissues, they represent only a final and single stage that does not capture dynamic evolution of environments and epigenetic programming in living humans.” “The epigenetics of perinatal stress”

Other reviewers try to ignore times when we were all fetuses and newborns. For example, in the same journal issue was a Boston review of PTSD that didn’t mention anything about earliest times of human lives! Those reviewers speculated around this obvious gap on their way to being paid by NIH.

Why would researchers ignore perinatal stress events that prime humans for later-life PTSD? Stress generally has a greater impact on fetuses and newborns than on infants, and a greater impact on infants than on adults.

Clearing out the 2019 queue of interesting papers

I’m clearing out the below queue of 27 studies and reviews I’ve partially read this year but haven’t taken the time to curate. I have a pesky full-time job that demands my presence elsewhere during the day. :-\

Should I add any of these back in? Let’s be ready for the next decade!

Early life “Early Behavioral Alterations and Increased Expression of Endogenous Retroviruses Are Inherited Across Generations in Mice Prenatally Exposed to Valproic Acid” (not freely available) “Consolidation of an aversive taste memory requires two rounds of transcriptional and epigenetic regulation in the insular cortex” (not freely available) “Intergenerational transmission of depression: clinical observations and molecular mechanisms” (not freely available)

mother “Epigenomics and Transcriptomics in the Prediction and Diagnosis of Childhood Asthma: Are We There Yet?” epigenetic clocks: estimating gestational age using placental DNA methylation levels” “Mismatched Prenatal and Postnatal Maternal Depressive Symptoms and Child Behaviours: A Sex-Dependent Role for NR3C1 DNA Methylation in the Wirral Child Health and Development Study” “Environmental influences on placental programming and offspring outcomes following maternal immune activation” “5-Hydroxymethylcytosine in cord blood and associations of DNA methylation with sex in newborns” (not freely available) “Paternal diet impairs F1 and F2 offspring vascular function through sperm and seminal plasma specific mechanisms in mice” “Sex differences in the epigenetic regulation of chronic visceral pain following unpredictable early life stress” (not freely available) “Genome-wide DNA methylation data from adult brain following prenatal immune activation and dietary intervention” in depression vulnerability and resilience: novel targets for preventive strategies”

Later life “Effect of Flywheel Resistance Training on Balance Performance in Older Adults. A Randomized Controlled Trial” “Eccentric Overload Flywheel Training in Older Adults” “Epigenetic regulation of the innate immune response to infection” (not freely available) “Hair Cell Regeneration” (not freely available) Modifications as an Intersection Between Diet and Longevity” “Serotonin transporter gene methylation predicts long-term cortisol concentrations in hair” (not freely available) “Frailty biomarkers in humans and rodents: Current approaches and future advances” (not freely available) “Neural mechanisms underlying adaptive and maladaptive consequences of stress: Roles of dopaminergic and inflammatory responses “In Search of Panacea—Review of Recent Studies Concerning Nature-Derived Anticancer Agents” “Reversal of oxycodone conditioned place preference by oxytocin: Promoting global DNA methylation in the hippocampus” (not freely available) “Different epigenetic clocks reflect distinct pathophysiological features of multiple sclerosis” “The Beige Adipocyte as a Therapy for Metabolic Diseases” “Bone adaptation: safety factors and load predictability in shaping skeletal form” (not freely available) “Successful treatment of post-traumatic stress disorder reverses DNA methylation marks” (not freely available) “Editing the Epigenome to Tackle Brain Disorders” (not freely available)

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.” “How can memories last for days, years, or a lifetime? Proposed mechanisms for maintaining synaptic potentiation and memory”

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 yet to be examined is: How can humans best address these early-life causes to ameliorate their lifelong effects? “Early environmental influences on the development of children’s brain structure and function” (not freely available)