Do broccoli sprouts treat gout and kidney stones?

This 2022 rodent study investigated glucoraphanin’s effects on reducing uric acid:

“Hyperuricemia is a chronic disease characterized by abnormally elevated serum uric acid levels. Sulforaphane could lower uric acid by decreasing urate synthesis and increasing renal urate excretion in hyperuricemic rats.

A hyperuricemia model was established by administering feedstuffs with 4% potassium oxonate and 20% yeast. Forty male Sprague–Dawley rats were randomly divided into the normal control, hyperuricemia, allopurinol, and sulforaphane groups. Animals were treated by oral gavage for six consecutive weeks, and then phenotypic parameters, metabolomic profiling, and metagenomic sequencing were performed.


We identified succinic acid and oxoglutaric acid as critical host-gut microbiome co-metabolites. Sulforaphane improved diversity of microbial ecosystems and functions, as well as metabolic control of the kidney. Sulforaphane exerted its renoprotective effect through epigenetic modification of Nrf2 and interaction between gut microbiota and epigenetic modification in hyperuricemic rats.

Limitations of this study include:

  1. We used glucoraphanin bioactivated with myrosinase for our experiments. Future experiments may directly involve sulforaphane.
  2. Bioinformatics analysis resulted in speculations that require further experimental testing.
  3. Further investigation of interactions between microbiota and the host epigenome is still needed.” “Sulforaphane-driven reprogramming of gut microbiome and metabolome ameliorates the progression of hyperuricemia”

It was a stretch to label treatment subjects as the “sulforaphane group” by claiming “Glucoraphanin (10 mg/kg) was metabolized to SFN by myrosinase as described in previous studies.” Both this and the referenced 2014 study “(RS)-glucoraphanin purified from Tuscan black kale and bioactivated with myrosinase enzyme protects against cerebral ischemia/reperfusion injury in rats” measured glucoraphanin and myrosinase, but not sulforaphane.

A human equivalent to this study’s daily glucoraphanin intake of 10 mg / kg weight would be (.162 x 10 mg) x 70 kg = 113 mg. Whether 10 mg was dry or wet weight wasn’t disclosed.

If 10 mg was wet, 113 mg is a little more than twice our model clinical trial’s average glucoraphanin intake of 51 mg fresh weight from eating 30 grams / day of super sprouts. In April 2020’s Understanding a clinical trial’s broccoli sprout amount, a study coauthor said:

“We considered 30 g and 60 g to be 1/2 and 1 portion per day, respectively, of broccoli sprouts. When we carried out tests with consumers, previous to the bioavailability studies, higher amounts per day were not easy to consume and to get eaten by participants.”


Broccoli sprouts activate the AMPK pathway, Part 4

Today someone viewed the 2020 Part 3 of Broccoli sprouts activate the AMPK pathway which lacked citations at the time. Checking again, here are three citing 2022 papers, starting with a review:

“Nrf2 is an important transcription factor that regulates expression of a large number of genes in healthy and disease states. Nrf2 regulates expression of several key components of oxidative stress, mitochondrial biogenesis, mitophagy, autophagy, and mitochondrial function in all organs of the human body, and in the peripheral and central nervous systems.

Overall, therapeutic drugs including sulforaphane that target Nrf2 expression and Nrf2/ARE pathway are promising. This article proposes additional research in Nrf2’s role within Parkinson’s disease, Huntington’s disease, and ischemic stroke in preclinical mouse models and humans with age-related neurodegenerative diseases.” “Role of Nrf2 in aging, Alzheimer’s and other neurodegenerative diseases” (not freely available) Thanks to Dr. P. Hemachandra Reddy for providing a copy.

One of the Part 3 study’s coauthors contributed to this very detailed review:

“Due to observed overlapping cellular responses upon AMPK or NRF2 activation and common stressors impinging on both AMPK and NRF2 signaling, it is plausible to assume that AMPK and NRF2 signaling may interdepend and cooperate to readjust cellular homeostasis.


The outcome and underlying signaling events of AMPK-NRF2 crosstalk may diverge between:

  1. in vitro and in vivo studies (one cell type in isolation vs inter-organ crosstalk in living organisms);
  2. Different cell types/organs/organisms of different cultivation conditions, genetic background, age or sex;
  3. Different stress-regimens (chronic vs acute, nature of stress (lipotoxicity, redox stress, xenobiotic, starvation, etc));
  4. Different modes of Nrf2 or AMPK activation and inhibition (genetic vs pharmacological, constitutive vs transient/intermittent, systemic vs organ-specific, electrophilic vs PPI, allosteric vs covalent, or pan vs subtype-specific);
  5. Different target genes with distinct promoter and enhancer structure; or
  6. Different timing of activation.

The latter should deserve increased attention as Nrf2 is one of the most cycling genes under control of the circadian clock. Feeding behavior, metabolism and hence AMPK activity follow and substantiate the biological clock, indicating an entangled circadian regulation of metabolic and redox homeostasis.” “AMPK and NRF2: Interactive players in the same team for cellular homeostasis?”

A third citing paper was a study of lens cells that provided an example of similar metformin effects noted in Part 2 of Broccoli sprouts activate the AMPK pathway:

“Loss of Nrf2 and Nrf2 antioxidant genes expression and activity in aging cells leads to an array of oxidative-induced deleterious responses, impaired function, and aging pathologies. This deterioration is proposed to be the primary risk factor for age-related diseases such as cataracts.

AMPK regulates energy at physiological levels during metabolic imbalance and stress. AMPK is a redox sensing molecule, and can be activated under cellular accumulation of reactive oxygen species, which are endogenously produced due to loss of antioxidant enzymes.

The therapeutic potential of AMPK activation has context-dependent beneficial effects, from cell survival to cell death. AMPK activation was a requisite for Bmal1/Nrf2-antioxidants-mediated defense, as pharmacologically inactivating AMPK impeded metformin’s effect.

Using lens epithelial cell lines (LECs) of human or mouse aging primary LECs along with lenses as model systems, we demonstrated that metformin could correct deteriorated Bmal1/Nrf2/ARE pathway by reviving AMPK-activation and transcriptional activities of Bmal1/Nrf2, resulting in increased antioxidants enzymatic activity and expression of Phase II enzymes. Results uncovered crosstalk between AMPK and Bmal1/Nrf2/antioxidants mediated by metformin for blunting oxidative/aging-linked pathobiology.” “Obligatory Role of AMPK Activation and Antioxidant Defense Pathway in the Regulatory Effects of Metformin on Cellular Protection and Prevention of Lens Opacity”


If you were given a lens to see clearly, would you accept it?

Two papers, starting with a 2022 rodent study of maternal behaviors’ effects on offspring physiologies:

Early life adversity (ELA) is a major risk factor for development of pathology. Predictability of parental care may be a distinguishing feature of different forms of ELA.

We tested the hypothesis that changes in maternal behavior in mice would be contingent on the type of ELA experienced, directly comparing predictability of care in the limited bedding and nesting (LBN) and maternal separation (MS) paradigms. We then tested whether predictability of the ELA environment altered expression of corticotropin-releasing hormone (Crh), a sexually-dimorphic neuropeptide that regulates threat-related learning.

MS was associated with increased expression of Crh-related genes in males, but not females. LBN primarily increased expression of these genes in females, but not males.” “Resource scarcity but not maternal separation provokes unpredictable maternal care sequences in mice and both upregulate Crh-associated gene expression in the amygdala”

I came across this first study by it citing a republished version of 2005 epigenetic research from McGill University:

“Early experience permanently alters behavior and physiology. A critical question concerns the mechanism of these environmental programming effects.

We propose that epigenomic changes serve as an intermediate process that imprints dynamic environmental experiences on the fixed genome resulting in stable alterations in phenotype. These findings demonstrate that structural modifications of DNA can be established through environmental programming and that, in spite of the inherent stability of this epigenomic marker, it is dynamic and potentially reversible.” “Environmental programming of stress responses through DNA methylation: life at the interface between a dynamic environment and a fixed genome”

This post commemorates the five-year anniversary of Dr. Arthur Janov’s death. Its title is taken from my reaction to his comment on Beyond Belief: Symptoms of hopelessness. Search his blog for mentions of the second paper’s coauthors, Drs. Meaney and Szyf.


Measuring epigenetic DNA causes

This 2022 human cell study investigated DNA methylation and aging:

“Models based on DNA methylation can be used to predict the age of biological samples, but their interpretability is limited due to the lack of causal inferences. Neither existing epigenetic clocks nor DNA methylation changes are enriched in causal CpG sites. Causal CpGs include similar numbers of sites that contribute to aging and protect against it, yet their combined contribution negatively affects age-related traits.

One general approach for developing anti-aging interventions is to identify molecular changes during aging and use these changes as targets to modulate the aging process. A similar idea has also been applied to evaluate potential longevity interventions. However, this logic is intrinsically flawed, as correlation does not imply causation, and age-related changes are not necessarily causal to age-associated declines.

We developed a framework for integrating causal knowledge into epigenetic clock models and constructed DamAge and AdaptAge that measure age-related damaging and adaptive changes, respectively. DamAge acceleration is associated with various adverse conditions (e.g., mortality risk), whereas AdaptAge acceleration is related to beneficial adaptations.

causality clocks

We found that transcription factor (TF)-binding sites of BRD4 and CREB1 are enriched with CpG sites whose methylation levels promote healthy longevity, and TF-binding sites for HDAC1 are enriched with CpG sites whose methylation levels decrease healthy longevity.

  • BRD4 contributes to cell senescence and promotes inflammation, and higher DNA methylation at BRD4 binding sites may inhibit the downstream effects of BRD4 and promote healthy longevity.
  • CREB1 is related to type II diabetes and neurodegeneration, and mediates the effect of calorie restriction. Our data suggest that higher methylation at CREB1-binding sites may support its longevity effects.
  • HDAC1 is a histone deacetylase, and its activity increases with aging and may promote age-related phenotypes. Increased DNA methylation at HDAC1 binding sites may causally inhibit healthy longevity.

Our causality-informed clock models provide novel insights into the aging mechanisms and testing interventions that delay aging and reverse biological age.” “Causal Epigenetic Age Uncouples Damage and Adaptation”


How to measure biological age?

As mentioned in Week 127, I had biological age measured earlier this month, and received five reports two days ago on Sunday. Part of the company’s process is to follow up their reports (intrinsic aging, immune aging, pace of aging, telomere length, weight loss) with a consulting session to review and interpret, which lasted an hour yesterday.

Part of our conversation revolved around comparing my measurements with other customers. These people are a different population than people usually sampled for aging and other biomarkers, because people who pay to get their biological age measured probably actionably want to improve it.

We’ll see which items I asked the consultant to pass on to the company produce responses, and which interfere with their business or they’re too busy to get back to me. I offered more than a half-dozen specifics, but held back on items I didn’t think the consultant would adequately communicate.

I didn’t argue with the consultant’s recommendations for quercetin supplementation (at 4% bioavailability?) as part of a treatment for senescence (not measured in any of the reports?). I didn’t offer to follow-up with studies demonstrating yeast cell wall β-glucan (new to the consultant) effects on immune report findings here in my 19th year of taking it every day.

I did argue with their recommendation to take DHEA-S. I changed my mind about taking it a year and a half ago ago, but left blog posts up such as Take responsibility for your one precious life – DHEA for evidence that I’m learning.

Epigenetic clocks per The epigenetic clock theory of aging generally view biological aging as “an unintended consequence of both developmental programmes and maintenance programmes, the molecular footprints of which give rise to DNAm [DNA methylation] age estimators.”

So what would be appropriate anti-aging actions for customers to take? Should customers try to emulate youthful biological markers, and supplement DHEA-S to impact serum levels of insulin-like growth factor 1?

I don’t think so. Our bodies never evolved feedback mechanisms to determine “Time to stop the growth programs, you’ve survived to reproduction age.” Older people achieving teenagers’ DHEA-S levels and activating IGF-1 pathways, pretty much guarantees further biological aging as “an unintended consequence of both developmental programmes and maintenance programmes.”

It’s too early to recommend these biological aging measurements. We’ll see where it goes.

One good thing is the company wants their customers to tell them everything about what they’re doing. I exercise at least a half hour every day, eat Avena nuda oats for breakfast and AGE-less chicken vegetable soup for dinner, and take the following:

Before breakfast
– 3-day-old microwaved broccoli / red cabbage / mustard sprouts started from 10.7 grams of seeds, with nothing else an hour before or after
– Yeast cell wall β-glucan (Glucan 300), 1500 mg, with nothing else an hour before or after

Breakfast, lunch, and dinner
– Hyaluronic acid, Nature’s Lab, 1 serving total
– Boron, Swanson Triple Boron Complex, 9 mg total

Breakfast and dinner
Acetyl-L-carnitine, 1 g total
– Balance oil, which blends linoleic acid 1400 mg with linolenic acid 350 mg, 2 times
– Betaine anhydrous, 3 g total
– Glucosamine hydroxychloride 1.5 g total, with chondroitin sulfate 1.2 g total
Taurine, 2 g total
– 3-day-old Avena sativa oat sprouts started from 20 g seeds, 2 times

Breakfast only
– Minerals and vitamins, RDA mainly, Kirkland Signature Daily Multi
– D3 25 mcg
– Calcium alpha-ketoglutarate 1 g

Lunch only
– Vitamin K2 MK-7 600 mcg

Dinner only
– D3 50 mcg
– Zinc monomethionine 30 mg with 0.3 mg copper
– Lutein 25 mg with 5 mg zeaxanthin


An inflammation clock

Here are six 2022 papers that either cited the second study of Variable aging measurements, or provided further evidence for its findings. Let’s start with a citing study:

“This study aimed to investigate expression patterns and prognostic values of the inflammatory aging clock (iAge) in glioblastoma (GBM), and its relations with stem cells. Similar to epigenetic clocks and transcriptomic clocks, iAge could track multifaceted aging phenotypes and have clinical significance in translation medicine.

iAge was positively correlated with chronological age, and highly associated with immune cells and inflammatory activities. iAge could serve as a prognostic biomarker for overall survival, and could precisely predict GBM stem cells stemness.

We identified the physiological importance and function of iAge in GBM, and provided novel insights into how iAge is a critical event for development of GBM.” “Inflammatory aging clock: A cancer clock to characterize the patients’ subtypes and predict the overall survival in glioblastoma”

Beginning with a human osteoporosis study, five papers investigated cytokine CXCL9, which the iAge study found to be “clearly actionable as shown by our experiments in CXCL9 where we can reverse aging phenotypes.”

“We assessed whether levels of CXCL9 and CXCL10 were elevated in human serum samples of older adults who had incident hip fractures. Our findings revealed higher serum levels of CXCL9 in pre-fracture blood samples of men with subsequent hip fractures, compared with their non-fracture controls. There was no such difference in CXCL9 serum levels between cases and controls in women.

Serum CXCL9 improved the prediction of osteoporotic hip fracture in men. The association between CXCL10 and hip fracture risk was not statistically significant in either sex.

While our epidemiologic findings are supported by experimental data providing the mechanistic pathway for CXCL9 in regulating osteoclast recruitment, further studies are needed to confirm validity of our findings and determine their generalizability to other study populations. Underlying biological mechanisms that limit our findings to men but not women require further investigation.” “CXCL9 Predicts the Risk of Osteoporotic Hip Fracture in a Prospective Cohort of Chinese Men—A Matched Case–Control Study”

Two immune-mediated skin diseases, with a vitiligo review:

“Current findings emphasize the critical role of immune cells and their mediators in the immunopathogenesis of vitiligo. IFN-γ [interferon gamma] is the primary cytokine mediator that activates the JAK/STAT pathway, causing keratinocytes to produce the key chemokines CXCL9 and CXCL10.

Interactions between immune and non-immune cells finally result in apoptosis of melanocytes. Additional investigations of these pathways may provide an opportunity for finding possible therapeutic targets, as there are currently no targeted biological drugs available for treatment of vitiligo.” “Current Concepts of Vitiligo Immunopathogenesis”

and a study of psoriasis:

“CXCL9 is an important chemokine involved in T cell recruitment, and is up-regulated in plasma of patients with psoriasis. Increased CXCL9 expression can aggravate the progression of psoriasis.

cxcl9 expression

IL-1β and CXCL9 were up-regulated and CLDN8 was down-regulated in psoriasis with statistically significant differences. Identification of potential key molecular markers and signaling pathways provides potential research directions for further understanding molecular mechanisms of psoriasis.” “Identification of potential key molecules and signaling pathways for psoriasis based on weighted gene co-expression network analysis”

Two lung-related studies, first, an editorial for a human lung transplant study that isn’t freely available:

“CXCL9 and CXCL10 are chemokines that bind to the shared receptor CXCR3, potentiating T cells, mononuclear cells, and natural killer (NK) cells. Previous studies demonstrated that presence of these chemokines in bronchoalveolar lavage samples preceded development of chronic lung allograft dysfunction (CLAD).

Acute rejection and acute lung injury are known risk factors to the development of CLAD, yet this study found that increased risk was dependent on the presence of CXCL9/CXCL10 plasma elevation. Early identification of patients at risk, possibly during the active inflammatory phase, rather than once abnormal wound healing pathways dominate resulting in irreversible injury, provides an attractive opportunity for intervention.” “CXCL9 and CXCL10 plasma levels: Potential keys to unlocking CLAD risk”

and a study of smoking effects:

“We collected blood samples from 78 healthy male volunteers aged 18–60, including non-smokers (n = 30), current smokers (n = 30), and ex-smokers (n = 18). Expression levels of CXCL9/MIG [monokine induced by IFN-γ] and sIL-6R significantly increased after smoking, and continued to increase after quitting smoking.

cxcl9 smoking

Changes in related cytokines after smoking cessation are mainly restorative, while some cytokines further strengthen the trend of smoking-related changes.” “Effects of Smoking on Inflammatory-Related Cytokine Levels in Human Serum”


Natural sulforaphane effects

This 2022 rodent cell study used the natural form of sulforaphane to replicate experiments performed with mixtures of its natural and unnatural forms:

“Natural sulforaphane (SFN) exists as a single enantiomer with a RS absolute configuration. Most studies focusing on its biological activities, in particular its anti-inflammatory and antioxidant activities, have been conducted using its racemic (rac) form. rac-SFN has shown these effects in several in vitro and in vivo models.


These findings demonstrate that (R)-SFN was able to:

  • Modulate inflammatory response and oxidative stress induced by LPS stimulation in murine peritoneal macrophages;
  • Reduce pro-inflammatory enzyme expression (iNOS, COX-2 and mPGES-1) and cytokine production (IL-1β, IL-6, IL-17, IL-18 and TNF-α);
  • Inhibit MAPK, JAK2/STAT-3, and canonical and non-canonical inflammasome signaling pathways;
  • Reduce NO and ROS levels and up-regulate the Nrf-2/HO-1 axis; and
  • Modulate epigenetic changes through histone methylation (H3K9me3) and deacetylation (H3K18ac).

(R)-SFN could be a new epinutraceutical compound useful for management of several immunoinflammatory diseases.” “Immunomodulatory Effects of (R)-Sulforaphane on LPS-Activated Murine Immune Cells: Molecular Signaling Pathways and Epigenetic Changes in Histone Markers”


Epigenetic effects of plasma concentrate

“We use data from a safety study (n = 18, mean age 74) to investigate whether human umbilical cord plasma concentrate (hereinafter Plasma Concentrate) injected weekly (1 ml intramuscular) into elderly human subjects over a 10-week period affects different biomarkers, including epigenetic age measures, standard clinical biomarkers of organ dysfunction, mitochondrial DNA copy number (mtDNA-CN), and leukocyte telomere length.

More than 20 clinical biomarkers were significantly and beneficially altered. Telomere length and mtDNA-CN were not significantly affected by treatment.

An increase in entropy means that the methylome becomes noisier. We found that entropy was significantly decreased after treatment. Decreased entropy may implicate rejuvenation of the epigenetic landscape after plasma concentrate treatments.

changes in methylation entropy

Treatment reduced DNA methylation-based GrimAge by an average of 0.82 years, suggesting a reduction in morbidity and mortality risk. By contrast, no significant results could be observed for epigenetic clocks that estimate chronological age.

Our study lends credence to the notion that there are youth-promoting factors in the secretome of umbilical cord plasma. This conclusion has also been reached by other researchers that have provided treatment with stem cells, which do not work by plasma dilution but primarily by providing humoral factors and changing the microenvironment of cells and tissues. While there may be youth-promoting microvesicles or humoral factors that are at work, we do not want to rule out the possibility that it is ‘young and undamaged’ albumin that leads to the improvements noted, especially in light of recent evidence for such a mechanism.

This first human epigenetic clock study of plasma concentrate treatments revealed age-reversal effects according to a well-established DNA methylation-based estimator of morbidity and mortality risk. Future placebo-controlled replication studies are warranted with a larger number of participants over a longer study period, which our laboratory has undertaken to pursue.” “Umbilical cord plasma concentrate has beneficial effects on DNA methylation GrimAge and human clinical biomarkers”


Epigenetic clocks so far in 2022

2022’s busiest researcher took time out this month to update progress on epigenetic clocks. If I curated every study he’s contributed to, it would require at least three blog posts a week. I’ll link to a few he’s posted in August 2022 that are more appreciated in the researcher community.

“In my lab, we are looking for clocks that apply to multiple species at the same time, for example, universal pan-mammalian clocks. It’s all about enhancing translation.

If you have an intervention that rejuvenates a mouse, a rat, a dog, and a cat according to the same clock, then chances are high that it will also work in humans. Naked Mole-Rat Hyaluronan Synthase 2 Promotes Longevity and Enhances Healthspan in Mice

Several groups, including mine, are working on single cell methylation clocks. Researchers are building clocks that respond to lifestyle interventions, such as exercise.

Moving away from methylation, it would be nice to build similar clocks for other ‘omics’ data. Many researchers build clocks on the basis of other omics data, such as for chromatin, proteomics, and gene expression.

There are different platforms, but they all attempt to measure the same thing: biological age. LINE-1 RNA causes heterochromatin erosion and is a target for amelioration of senescent phenotypes in progeroid syndromes

Epigenetic clocks are ‘life course clocks.’ I don’t know any other biomarkers of aging that applies to fetal tissues as well, because most other biomarkers measure organ dysfunction. Epigenetic profiling and incidence of disrupted development point to gastrulation as aging ground zero in Xenopus laevis

There’s this company called Intervene Immune, founded by Greg Fahy, and they are using GrimAge and other epigenetic clocks in clinical trials. They are doing a Phase II clinical trial. By the way, I’m one of the participants.

I could name several other groups who are using epigenetic clocks in clinical trials. It would be interesting if more people would measure epigenetic age in clinical trials in humans, at least as a secondary outcome, because there’s always an opportunity to make a discovery.

If you compare GrimAge to other biomarkers, such as cholesterol or glucose levels, you will see similar noise levels there. Epigenetic clocks are remarkably robust compared to what else is used in the clinic. I would say that the issue with technical noise in epigenetic clocks has been solved.

I’m really glad that different companies and researchers pursue different avenues, since it diversifies our risk. If one of these approaches works, it will change the world.” “Steve Horvath on the Present and Future of Epigenetic Clocks”


If you lose mobility, you lose cognitive function

This 2022 human study used four epigenetic clocks to assess aging:

“This cohort study was a secondary analysis of 3 Women’s Health Initiative (WHI) ancillary studies among 1813 women eligible to survive to age 90 years by end of study period. The study found that increased epigenetic age acceleration (EAA) as measured by 4 epigenetic clocks was associated with lower odds of survival to age 90 years with intact mobility; results were similar when including intact cognitive functioning.

This study benefited from a large, racially and ethnically diverse sample of women who were followed up to at least age 90 years with detailed longitudinal data on a host of lifestyle and health history factors. This study is generalizable to WHI women owing to use of IPW weights, and may be generalizable to a large range of women in the United States.


Among 1813 women, there were:

  • 464 women who survived to age 90 years with intact mobility and cognitive functioning;
  • 420 women who survived to age 90 years without intact mobility and cognitive functioning; and
  • 929 women who did not survive to age 90 years.

Only 29 women were reclassified from the healthy longevity group to surviving to age 90 years without intact mobility and cognitive functioning. Although it was of great interest to investigate the association between EAA and survival to age 90 years with intact cognitive function independently, this study population did not have sufficient numbers of women who experienced loss of cognitive function (without loss of mobility) to do so.” “Analysis of Epigenetic Age Acceleration and Healthy Longevity Among Older US Women”

Early humans who lost mobility in our African savanna ancestral environment during the Pleistocene Epoch (approximately 2.6M to 12K years ago) were prey. I highly doubt that immobile individuals successfully became our ancestors.

I downgraded this study because these researchers misguidedly soiled worthwhile findings with BMI and education level non-causal associations. They intentionally did this, as several of them were coauthors of the execrable Epigenome-wide meta-analysis of BMI in nine cohorts: examining the utility of epigenetic BMI in predicting metabolic health.

See Findings, or fun with numbers? and Does a societal mandate cause DNA methylation? for opposing research.


Broccoli sprouts and your brain

A 2022 review of Nrf2 signaling hilariously avoided mentioning sulforaphane, although of ~4,000 sulforaphane published articles, two were cited. I’ll curate it anyway to highlight referenced brain effects.

“A good stability of NRF2 activity is crucial to maintain redox balance and therefore brain homeostasis. In this review, we have gathered recent data about the contribution of the NRF2 pathway in the healthy brain as well as during metabolic diseases, ageing, and ageing-related neurodegenerative diseases.

A functional NRF2 system is important to regulate both neuroinflammation, i.e., activation of microglia and astrocytes, and oxidative stress in the brain. NRF2 and NF-κB transcription factors regulate cellular responses to inflammation and oxidative stress in order to maintain brain homeostasis. Both pathways have been described to inhibit each other.

Nrf2 brain aging

Future challenges will be to establish novel therapies to:

  • Increase NRF2 activation in specific cell types and/or brain regions; and
  • Modulate NRF2 pathway in senescent cells.

Modulation of NRF2 signalling pathway by using specific food products [like unmentioned broccoli sprouts] and phytochemicals [like unmentioned sulforaphane], dietary supplements [like unmentioned Vitamin D3], drugs, and epigenetic modifiers, alone or in combination, will help to limit inflammatory diseases, ageing process, and subsequently ageing-related diseases.” “Normal and Pathological NRF2 Signalling in the Central Nervous System”


Trained immunity epigenetics

Two papers on trained immunity, starting with a 2022 review:

“Live attenuated vaccines such as the Bacillus Calmette–Guérin, measles-containing vaccines, and the oral polio vaccine have been shown to reduce overall mortality beyond their effects attributable to the targeted diseases.

After an encounter with a primary stimulus, epigenetic and metabolic reprogramming of bone marrow progenitor cells and functional changes of tissue immune cell populations result in augmented immune responses against a secondary challenge. This process has been termed trained immunity.

Main epigenetic events during induction of trained immunity are:

  1. Chromosomal reorganization on the level of topologically associated domains;
  2. Induction of long noncoding RNA activity;
  3. Histone modifications and chromatin accessibility; and
  4. DNA (de)methylation.

trained immunity mechanisms

An epigenetic enzyme belonging to the lysine methyltransferase family, Set7, possesses vital function in β-glucan training of monocytes. When inhibited, trained immunity phenotype is diminished, while Set7 deficient mice cannot establish innate immune memory.

β-glucan is recognized by Dectin-1, and has been known to lead to a shift from oxidative phosphorylation (OXPHOS) to glycolysis as an ATP source. However, a more recent study reported an increase in both glycolysis and oxygen consumption following training, which signals a higher rate of OXPHOS. This discrepancy is explained by the difference in concentration of β-glucan used in the experiments.

Stopping vaccination with measles and polio once the pathogens are eradicated, or replacing live attenuated polio with inactivated polio, should be done with caution, as it may have a substantial impact on childhood mortality. Trained immunity may also represent an important new approach to improve current vaccines, or to develop novel vaccines that combine induction of classical adaptive immune memory and innate immune memory.” “Trained immunity: implications for vaccination”

Reference 34 was a 2020 study by two of the same coauthors that provided details on the above discrepancy:

“Findings presented by the current study suggest that the disparity in terms of the role of OXPHOS arises from the stimulatory dose of β-glucan [by intraperitoneal injection]. A β-glucan concentration of 1 μg/mL induces both glycolysis and OXPHOS, whereas a concentration of 10 μg/mL induces glycolysis but inhibits OXPHOS.” “The Set7 Lysine Methyltransferase Regulates Plasticity in Oxidative Phosphorylation Necessary for Trained Immunity Induced by β-Glucan”


The goddess of rainbows

Two 2022 papers, starting with a review of irisin:

“This article is an overview of irisin generation, secretion, and tissue distribution. Its targeting of tissues or organs for prevention and treatment of chronic diseases is systematically summarized, with discussion of underlying molecular mechanisms.

Irisin is an exercise-induced myokine expressed as a bioactive peptide in multiple tissues and organs. Exercise and cold exposure are major inducers for its secretion.

Mechanistic studies confirm that irisin is closely correlated with lipid metabolism, insulin resistance, inflammation, ROS, endocrine, neurotrophic factors, cell regeneration and repairing, and central nervous system regulation. Irisin decreases with age, and is closely associated with a wide range of aging-related diseases.

A number of studies in elderly humans and animal models have shown that exercise can promote the body’s circulation and increase irisin levels in some tissues and organs. Resistance, aerobic, or combined exercise seem to play a positive role. However, exercise could not change serum irisin in some reported studies.

irisin human studies

There are large individual differences in exercise training in the elderly population. Since the half-life of irisin in the body is less than 1 h, it is necessary to pay attention to the time of blood sampling after a single exercise intervention. Some factors that impede detection of irisin levels in vivo include the half-life of irisin protein, sampling time, different tissues, and different health statuses before and after intervention.

It is worth noting that high-intensity exercise shows higher irisin levels even with the same energy expenditure during exercise. Precision studies of irisin in elderly subjects following exercise intervention need to be further clarified.” “Irisin, An Exercise-induced Bioactive Peptide Beneficial for Health Promotion During Aging Process” (not freely available) Thanks to Dr. Ning Chen for providing a copy.

A second paper was a human study too recent to be cited by the first paper. I’ll highlight its irisin findings:

“We investigated the complex relationship among DNAm based biomarkers of aging, including DNAmFitAge, a variety of physiological functioning variables, blood serum measures including cholesterol, irisin level, and redox balance, and the microbiome on 303 healthy individuals aged between 33 and 88 years with a diverse level of physical fitness. Regular exercise was associated with younger biological age, better memory, and more protective blood serum levels.

Our research intends to show that regular physical exercise is related to microbiota and methylation differences which are both beneficial to aging and measurable. Our research provides the first investigation between microbiome derived metabolic pathways and DNAm based aging biomarkers.

Irisin levels decrease with age (0.23 average decrease for every 1 year older). We found age-related decreases in irisin levels were attenuated by exercise training. The link between irisin to GrimAge Acceleration and FitAge Acceleration is a novel observation.

HDL is positively associated with irisin. HDL and irisin have complex roles in physiology, and the positive relationship we observe between physical exercise and HDL and irisin align with protective effects seen between HDL and irisin with glucose homeostasis.

This work further supports the biological importance of irisin to the aging process. It is possible our research motivates interventions to boost irisin, like through physical exercise, as possible anti-aging therapies.” “DNA methylation clock DNAmFitAge shows regular exercise is associated with slower aging and systemic adaptation


Variable aging measurements

Two papers on aging measurements, starting with a 2022 human study:

“We collected longitudinally across the adult age range a comprehensive list of phenotypes within four domains (body composition, energetics, homeostatic mechanisms and neurodegeneration / neuroplasticity) and functional outcomes. We integrated individual deviations from population trajectories into a global longitudinal phenotypic metric of aging.

blsa participant ages

We demonstrate that accelerated longitudinal phenotypic aging is associated with faster physical and cognitive decline, faster accumulation of multimorbidity, and shorter survival.” “Longitudinal phenotypic aging metrics in the Baltimore Longitudinal Study of Aging”

I disagree with this study’s methodology.

1. Although it acknowledged individual variability, nothing was done to positively adjust to those facts. What could have been done per A review of biological variability was:

“Obtain a measurement of variability that is independent of the mean to ensure to not confound changes in variability with shifts in mean.”

2. A usual research practice is to take at least three measurements, and use their average as representative. That wasn’t done here, maybe because of time and expense considerations?

3. An important measurement for physical function was the time to finish a 400 meter walk. I walk more than ten times that almost every day. I use the first 400 meters as a warmup period while getting to the beach to walk eastward and enjoy the predawn light and water animal activity. I concentrate on gait speed during the last third while walking westward on a straightaway bike path.

This study would measure my gait speed as a sometimes old person during the first 400 meters, rather than a gait speed that usually approaches a young person’s during the last 400 meters. Even if I tried to walk my fastest right out of the gate, I wouldn’t be surprised to find a decade or two difference by this study’s measurements between a morning walk’s first and last 400 meter gait speeds.

4. An important cognitive function measurement was the Digital Symbol Substitution Test, apparently taken during subjects’ fasted state? Sometimes after exercising, I’m okay cognitively when starting work in a fasted state at 6:30 a.m., and other times I’m tired.

Two days ago during the last hour of work 1:30-2:30 p.m., I did outstanding work, four hours after eating whole oats for breakfast, and after drinking two coffees and three teas. I took time to put together pieces of puzzles into proper contexts for management’s attention. My bosses weren’t too pleased with the story it told, but it is what it is.

5. Are measurements of how you start what matters? Or is it how you finish, as is common in competitive sports?

This study would measure my cognitive function as a sometimes old person, rather than performance that approaches a young person’s later in the workday. For both physical and cognitive function, my abilities to ramp up and come close to young people’s capabilities are features that I work on, not random, inconvenient measurement variability.

6. Blood measurements were downgraded as having “limited coverage of the four phenotypic domains.” These were taken to fit into specific paradigms and epigenetic clocks. They predictably failed to show causality, as acknowledged with:

“Our analysis showed strong associations between global longitudinal phenotypic score and changes in physical and cognitive function. We did not have sufficient observations to fully separate these two dimensions over time, which would have strengthened the assumption of causality.”

Nowhere in this study was it hinted that all measurements were downstream effects of unmeasured causes. A follow-on study could reanalyze these subjects’ blood samples, MRI, and other measurements for originating upstream factors of signaling pathways and cascades per Signaling pathways and aging and An environmental signaling paradigm of aging.

Reference 35 of this first study was a 2021 human and rodent study that was tossed in as a limitation with:

“We might not have all of the relevant phenotypic measures (for example, more detailed immune profiles) for all participants.”

Its findings included:

“From the blood immunome of 1,001 individuals aged 8–96 years, we developed a deep-learning method based on patterns of systemic age-related inflammation. The resulting inflammatory clock of aging (iAge) tracked with multimorbidity, immunosenescence, frailty and cardiovascular aging, and is also associated with exceptional longevity in centenarians.

Canonical markers of acute infection such as IL-6 and tumor necrosis factor-α were not major contributors to iAge, indicating that, except for IL-1β, infection-driven inflammatory markers of the acute inflammatory response do not contribute to age-related chronic inflammation.

We conducted a follow-up study in an independent cohort of 97 extremely healthy adults (aged 25–90 years) matched for cardiovascular risk factors (including conserved levels of high-sensitivity C-reactive protein), selected from a total of 151 recruited participants using strict selection criteria. In this healthy cohort, inflammation markers were measured using a 48-plex cytokine panel. Only 6 circulating immune proteins were significantly correlated with age, with CXCL9 again the largest contributor to age-related inflammation.

CXCL9 is a T-cell chemoattractant induced by IFN-γ and is mostly produced by neutrophils, macrophages and endothelial cells (ECs). We find that CXCL9 is mainly produced by aged endothelium and predicts subclinical levels of cardiovascular aging in nominally healthy individuals.

We did not find any significant correlation between known disease risk factors reported in the study (BMI, smoking, dyslipidemia) and levels of CXCL9 gene or protein expression. We hypothesize that one root cause of CXCL9 overproduction is cellular aging per se, which can trigger metabolic dysfunction.

As ECs but not cardiomyocytes expressed the CXCL9 receptor, CXCR3, we hypothesize that this chemokine acts both in a paracrine fashion (when it is produced by macrophages to attract T cells to the site of injury) and in an autocrine fashion (when it is produced by the endothelium) creating a positive feedback loop. In this model, increasing doses of CXCL9 and expression of its receptor in these cells leads to cumulative deterioration of endothelial function in aging.

IFN-γ did not increase in expression in our cellular aging RNA-seq experiment, suggesting that there are triggers of CXCL9 (other than IFN-γ) that play a role in cellular senescence in the endothelium that are currently unknown. However, in our 1KIP study, IFN-γ was in fact the second-most important negative contributor to iAge, which could be explained by the cell-priming effect of cytokines, where the effect of a first cytokine alters the response to a different one.

iAge derived from immunological cytokines gives us an insight into the salient cytokines that are related to aging and disease. A notable difference compared to other clocks is that iAge is clearly actionable as shown by our experiments in CXCL9 where we can reverse aging phenotypes. More practical approaches range from altering a person’s exposomes (lifestyle) and/or the use of interventions to target CXCL9 and other biomarkers described here.

Our immune metric for human health can identify within healthy older adults with no clinical or laboratory evidence of cardiovascular disease, those at risk for early cardiovascular aging. We demonstrate that CXCL9 is a master regulator of vascular function and cellular senescence, which indicates that therapies targeting CXCL9 could be used to prevent age-related deterioration of the vascular system and other physiological systems as well.” “An inflammatory aging clock (iAge) based on deep learning tracks multimorbidity, immunosenescence, frailty and cardiovascular aging”


Non-CpG methylation

Three 2022 papers on methylation epigenetic modifiers, starting with a human study focused on mitochondrial DNA non-CpG methylation involving nucleobases other than guanine (arginine, cytosine, or thymine):

“We collected brain tissue in the nucleus accumbens and prefrontal cortex from deceased individuals without (n = 39) and with (n = 14) drug use, and used whole-genome bisulfite sequencing to cover cytosine sites in the mitochondrial genome. Epigenetic clocks in illicit drug users, especially in ketamine users, were accelerated in both brain regions by comparison with nonusers.

Unlike the predominance of CpG over non-CpG methylation in the nuclear genome, the average CpG and non-CpG methylation levels in the mitochondrial genome were almost equal. The utility of non-CpG methylation was further illustrated by the three indices constructed in this study with non-CpG sites having better distinction between brain areas, age groups, and the presence or absence of drug use than indices consisting of CpG sites only. Results of previous studies on the mitochondrial genome that were solely based on CpG sites should be interpreted cautiously.

The epigenetic clock made up of age-related cytosine sites in mtDNA of the control group was consistently replicated in these two brain regions. One possibility for the correlation is the cycle theory that involves mitochondrial activity, mitochondrial DNA methylation, and alpha-ketoglutarate.

As mitochondrial activity fades with aging, mitochondria gradually lose the ability to eliminate methylation on cytosines through alpha-ketoglutarate. Further investigation of the underlying mechanisms is warranted.

To our knowledge, this is the first report that ketamine might change the mitochondrial epigenetic clock in human brain tissues. We believe this is the first report to elucidate comprehensively the importance of mitochondrial DNA methylation in human brain.” “Mitochondrial DNA methylation profiling of the human prefrontal cortex and nucleus accumbens: correlations with aging and drug use”

A second rodent study focused on RNA methylation:

“We investigated the role of RNA N6-methyladenosine (m6A) in improved resilience against chronic restraint stress. A combination of molecular, behavioral, and in vivo recording data demonstrates exercise-mediated restoration of m6A in the mouse medial prefrontal cortex, whose activity is potentiated to exert anxiolytic effects. To provide molecular explanations, it is worth noting that epigenetic regulation, such as histone modification, microRNA, and DNA methylation all participate in mental and cognitive rehabilitation following exercise.

To generalize these rodent data to humans, we recruited a small group of patients with major depressive disorder with prominent anxiety disorders. Compared to age- and sex-matched healthy individuals, patients displayed decreased circulating methyl donor S-adenosyl methionine (SAM) levels. Serum SAM levels were found to be inversely correlated with the Hamilton Anxiety Scale, suggesting the potential value of SAM as a biomarker for depression or anxiety disorders.

Hepatic biosynthesis of methyl donors is necessary for exercise to improve brain RNA m6A to counteract environmental stress. The dependence on hepatic-brain axis suggests the ineffectiveness of exercise training on people with hepatic dysfunctions.

This novel liver-brain axis provides an explanation for brain network changes upon exercise training, and provides new insights into diagnosis and treatment of anxiety disorders. Exercise-induced anxiolysis might be potentiated by further replenishment of RNA methylation donors, providing a strategy of exercise plus diet supplement in preventing anxiety disorders.” “Physical Exercise Prevented Stress-Induced Anxiety via Improving Brain RNA Methylation”

A third paper was a review of mitochondrial-to-nuclear epigenetic regulation. I’ll highlight one mitochondrial metabolite, alpha-ketoglutarate (α-KG):

“Apart from established roles in bioenergetics and biosynthesis, mitochondria are signaling organelles that communicate their fitness to the nucleus, triggering transcriptional programs to adapt homeostasis stress that is essential for organismal health and aging. Emerging studies revealed that mitochondrial-to-nuclear communication via altered levels of mitochondrial metabolites or stress signals causes various epigenetic changes, facilitating efforts to maintain homeostasis and affect aging.

Metabolites generated by the tricarboxylic acid (TCA) cycle, the electron transport chain (ETC), or one-carbon cycle within mitochondria can act as substrates or cofactors to control epigenetic modification, especially histone acetylation and methylation and DNA methylation. α-KG produced in the TCA cycle serves as an essential cofactor for the chromatin-modifying Jumonji C (JmjC) domain-containing lysine demethylases (JMJDs) and ten-eleven translocation (TETs) DNA demethylases. Changes in α-KG levels are capable of driving nuclear gene expression by affecting DNA and histone methylation profiles.


α-KG deficiency in progenitor stem cells increases with age. For example, the level of α-KG is reduced in follicle fluids of aged humans, and supplementation with α-KG preserves ovarian function in mice.

α-KG extends lifespan in Drosophila by activating AMPK signaling and inhibiting the mTOR pathway. Supplementing α-KG in the form of a calcium salt promoted a longer and healthier life associated with decreased levels of inflammatory cytokines in old mice.

A human study showed a nearly 8-year reversal in DNA methylation clock biological ages of 42 individuals taking an α-KG based formulation for 4–10 months. α-KG supplementation leads to both demethylation and hypermethylation of some CpG sites in the genome, suggesting that α-KG may have a broader effect on methylation-based aging, such as metabolic functions.

Outstanding questions:

  1. How is production of mitochondrial metabolites regulated both spatially and temporally to elicit epigenetic changes in response to mitochondrial dysfunction?
  2. What are specific epigenetic factors involved in mitochondrial-to-nuclear communications, and how do they cooperate with transcription factors in response to various external and internal stimuli?
  3. Do various mitochondrial metabolites act alone or in concert on the epigenome to regulate the aging process?
  4. Are some organs or tissues more at risk than others in maintaining mitochondrial-to-nuclear communication during aging?
  5. Can intervention of mitochondrial-to-nuclear communications mimic beneficial epigenetic changes to delay aging or alleviate age-onset diseases?” “Mitochondrial-to-nuclear communication in aging: an epigenetic perspective”