A Nrf2 / NAD+ connection?

Here are two 2025 papers, starting with a rodent study that investigated interactions between the Nrf2 and kynurenine pathways:

“Exposure to the tryptophan metabolite kynurenine and its electrophilic derivative kynurenine-carboxyketoalkene (Kyn-CKA) leads to an increase in the abundance of transcription factor Nrf2 and induction of Nrf2-target genes. The Keap1/Nrf2 system is the main orchestrator of cellular defence against environmental stress, most notably oxidative and inflammatory stress.

Nrf2 can be activated pharmacologically by small molecules, the majority of which are electrophiles and oxidants that modify specific cysteine-based sensors in Keap1. C151 in Keap1 is the target of the isothiocyanate sulforaphane, a classical Nrf2 activator that has been employed in ∼90 clinical trials, as well as for the two Nrf2 activators that are clinically in use: dimethyl fumarate, for relapsing remitting multiple sclerosis, and omaveloxolone, for Friedreich’s ataxia.

Kynurenine is an endogenous metabolite derived from the essential amino acid tryptophan. Kynurenine and its metabolites, such as the electrophilic kynurenine-carboxyketoalkene (Kyn-CKA), have been demonstrated to activate Nrf2 in other pathologies, including sickle cell disease, attenuating inflammation. Moreover, identification of the gene encoding the kynurenine-metabolising enzyme kynureninase as a gene transcriptionally upregulated by Nrf2, provides a plausible negative feedback regulatory mechanism.

Because kynurenine is not electrophilic, whereas its metabolite Kyn-CKA is, we considered the possibility that Kyn-CKA is the actual Nrf2 activator. Using biochemical and cell-based assays, we found that Kyn-CKA reacts with C151 in the BTB domain of Keap1 and increases the thermostability of Keap1, indicating target engagement. Consequently, Nrf2 accumulates and induces transcription of antioxidant/electrophile-responsive element (ARE/EpRE)-driven genes.

These findings demonstrate that Kyn-CKA targets C151 in Keap1 to derepress Nrf2, and reveal that Nrf2 is a main contributor to the anti-inflammatory activity of Kyn-CKA in macrophages.”

https://www.sciencedirect.com/science/article/pii/S2213231726000078 “The electrophilic metabolite of kynurenine, kynurenine-CKA, targets C151 in Keap1 to derepress Nrf2”


A review subject was targeting nicotinamide adenine dinucleotide, oxidized form (NAD+) for clinical use:

“Mammalian NAD+ biosynthesis includes four known pathways, primarily occurring in cytoplasm:

  • (a) the NRH pathway;
  • (b) the salvage pathway;
  • (c) the Preiss–Handler pathway; and
  • (d) the kynurenine pathway.

The de novo kynurenine pathway metabolizes tryptophan (Trp) to NAD+, producing various intermediates that serve as biomarkers for different diseases. These intermediates show alterations in various pathological conditions.

While kynurenine and its metabolic derivatives are intermediates in the de novo NAD+ biosynthesis pathway, these are also produced independently in various physiological contexts, particularly in immune cells, where they act as immunomodulatory compounds.”

https://www.nature.com/articles/s43587-025-00947-6 “Emerging strategies, applications and challenges of targeting NAD+ in the clinic” (not freely available) Thanks to Dr. Jianying Zhang for providing a copy.


This second paper above showed a graphic of the Nrf2 and kynurenine pathways together in a diagram showing relationships between NAD+ augmentation and the hallmarks of aging, but didn’t elaborate other than labeling their box Dysbiosis. So how these two pathways interact is better outlined in the first paper above with explaining how a kynurenine-metabolizing enzyme is one of the hundreds of Nrf2 target genes, creating a natural feedback loop between Nrf2 activation and the kynurenine pathway.

These reviewers also lumped SIRT1 in their Dysbiosis box, and into several other boxes, probably due to the penultimate coauthor’s influence:

However, repeating something over and over doesn’t make it scientifically valid regardless of the number of citations. Or, as a 2022 review Sirtuins are not conserved longevity genes concluded:

“A global pursuit of longevity phenotypes was driven by a mixture of framing bias, confirmation bias, and hype. Review articles that propagate these biases are so rampant that few investigators have considered how weak the case ever was for sirtuins as longevity genes.

Acknowledging that a few positive associations between sirtuins and longevity have been identified after thousands of person-years and billions of dollars of effort, we review the data and suggest rejection of the notions that sirtuins (i) have any specific connection to lifespan in animals and (ii) are primary mediators of the beneficial effects of NAD repletion.”

Practice what you preach, or shut up

A 2025 review subject was sulforaphane and brain health. This paper was the latest in a sequence where the retired lead author self-aggrandized his career by citing previous research.

He apparently doesn’t personally do what these research findings suggest people do. The lead author is a few weeks older than I am, and has completely white hair per an interview (Week 34 comments). I’ve had dark hair growing in (last week a barber said my dark hair was 90%) since Week 8 of eating broccoli sprouts every day, which is a side effect of ameliorating system-wide inflammation and oxidative stress.

If the lead author followed up with what his research investigated, he’d have dark hair, too. Unpigmented white hair and colored hair are both results of epigenetics.

Contrast this lack of personal follow-through of research findings with Dr. Goodenowe’s protocol where he compared extremely detailed personal brain measurements at 17 months and again at 31 months. He believes enough in his research findings to personally act on them, and demonstrate to others how personal agency can enhance a person’s life.

It’s every human’s choice whether or not we take responsibility for our own one precious life. I’ve read and curated on this blog many of this paper’s references. Five years ago for example:

So do more with their information than just read.

https://www.mdpi.com/2072-6643/17/8/1353 “Sulforaphane and Brain Health: From Pathways of Action to Effects on Specific Disorders”

2025 α-ketoglutarate research

I haven’t mentioned α-ketoglutarate for a while, although I’ve taken it twice a day for several years. Here are four 2025 papers on α-ketoglutarate, starting with a review of its role in bone health:

“α-Ketoglutarate (α-KG) serves as a pivotal intermediate in various metabolic pathways in mammals, significantly contributing to cellular energy metabolism, amino acid metabolism, and other physiological processes. α-KG may be a therapeutic target for a variety of bone-related diseases, such as osteoporosis, osteoarthritis, and rheumatoid arthritis, because of its role in maintaining metabolic balance of bone.

α-KG, as a rate-determining mitochondrial intermediate, is crucial in cell energy metabolism because it connects intracellular carbon and nitrogen metabolism between isocitrate and succinyl coenzyme A. Additionally, α-KG is closely involved in the amino acid cycle. As a precursor of amino acids such as glutamine and glutamic acid, α-KG plays a direct role in energy production and a wide range of cellular chemical reactions. α-KG provides an energy source, stimulating protein synthesis, inhibiting protein degradation in muscle, and serving as a significant metabolic fuel for gastrointestinal cells.

α-KG promotes osteogenic differentiation of stem cells, increases activity of osteoblasts to promote osteogenesis, and inhibits bone resorption activity of osteoclasts. α-KG in articular cartilage promotes differentiation and maturation of chondrocytes and formation of a cartilage matrix. The protective effect of α-KG on bone has practical value in treatment of abnormal bone loss symptoms in various bone tissue diseases.”

https://www.sciengine.com/ABBS/doi/10.3724/abbs.2025020 “Essential role of the metabolite α-ketoglutarate in bone tissue and bone-related diseases”


A rodent study explored adding α-KG to osteoarthritis treatment:

“Mesenchymal stem cell (MSC) therapy represents a promising treatment strategy for osteoarthritis (OA). Nevertheless, the therapeutic efficacy of MSCs may be attenuated under conditions of cellular senescence or when the available clinical quantity is insufficient. α-Ketoglutarate (AKG) exerts beneficial effects on skeletal tissues and activity of stem cells. The present study was designed to explore the potential of AKG in augmenting viability of MSCs and the potential of their combined utilization in treatment of OA.

AKG plays a crucial role in multiple biological processes. It is involved in regulating stem cell differentiation, exerts anti-apoptotic effects, modulates the body’s immune and inflammatory responses, contributes to muscle and bone development, and is essential for maintaining stability of the cartilage matrix.

Platelet-rich plasma (PRP) has been demonstrated to have protective effects on chondrocytes and can effectively repair damaged cartilage in OA. However, PRP has intractable problems in terms of product quality control and allogeneic application, and its long-term therapeutic effect gradually weakens.

Combining AKG’s regulation of cellular metabolism with the multi-directional differentiation and immunomodulatory functions of MSCs is likely to generate a synergistic effect. This combined treatment modality targets the complex pathological processes of OA, including cartilage damage, inflammatory responses, and extracellular matrix imbalance, in a more comprehensive manner than a single therapy.”

https://www.sciencedirect.com/science/article/pii/S2707368825000032 “The repair effect of α-ketoglutarate combined with mesenchymal stem cells on osteoarthritis via the hedgehog protein pathway”


A rodent study investigated whether α-KG has a role in determining frailty:

“Frailty is an age-related geriatric syndrome, for which the mechanisms remain largely unknown. We performed a longitudinal study of aging female (n = 40) and male (n = 47) C57BL/6NIA mice, measured frailty index, and derived metabolomics data from plasma samples.

We find that frailty related metabolites are enriched for amino acid metabolism and metabolism of cofactors and vitamins, include ergothioneine, tryptophan, and alpha-ketoglutarate, and present sex dimorphism. We identify B vitamin metabolism related flavin adenine dinucleotide and pyridoxate as female-specific frailty biomarkers, and lipid metabolism related sphingomyelins, glycerophosphoethanolamine and glycerophosphocholine as male-specific frailty biomarkers.

We were interested to observe whether metabolite abundance at any specific timepoint was associated with frailty at a future timepoint. Unfortunately, we didn’t observe any metabolites that showed an overall significant association with future FI (FIf) or future devFI (devFIf). When focusing only on the abundance of metabolites at the baseline time point (∼400 days), we found a single metabolite, alpha-ketoglutarate, was negatively associated with both FIf and devFIf.”

https://www.biorxiv.org/content/10.1101/2025.01.22.634160v1.full “Metabolomics biomarkers of frailty: a longitudinal study of aging female and male mice”


Wrapping up with a rodent study adding α-KG to exercise for its effects on depression and learning:

“aKG acts as a prophylactic and antidepressant to effectively counteract social avoidance behaviors by modulating BDNF levels in the hippocampus and nucleus accumbens. Exercise increases aKG levels in the circulation.

In mice, aKG supplementation prolongs lifespan and reduces aging-associated frailty. aKG supplementation also reverses aging in humans as measured by DNA methylation patterns.

aKG functions as a co-factor for epigenetic enzymes. Changes in the intracellular αKG/succinate ratio regulates chromatin modifications, including H3K27me3 and ten-eleven translocation (Tet)-dependent DNA demethylation. The ability of aKG to influence epigenetic status of cells may explain both its prophylactic and anti-depressant effects since transcriptional dysregulation and aberrant epigenetic regulation are unifying themes in psychiatric disorders. This may also explain its ability to differentially regulate BDNF expression in the hippocampus and NAc.

If exercise mediates its effects through aKG, aKG may be a pivotal component of an exercise pill along with lactate and BHB that can serve as both a prophylactic and antidepressant treatment for depression.”

https://www.sciencedirect.com/science/article/pii/S266717432500031X “α-ketoglutarate (aKG) is a circulatory exercise factor that promotes learning and memory recall and has antidepressant properties


Coffee compound effects

Three papers continue Polyphenol Nrf2 activators themes starting with a 2025 review of chlorogenic acid:

“Chlorogenic acid may comprise between 70 and 350 mg per cup of coffee. Chlorogenic acid can reduce reactive oxygen species (ROS) levels via the upregulation of antioxidant enzymes, decreasing oxidative stress/damage due to the action of adaptive hormetic mechanisms. There is also a substantial literature of hormetic dose responses for metabolites of chlorogenic acid, such as caffeic acid and ferulic acid.

Chlorogenic acid-induced hormetic biphasic dose responses in a spectrum of experimental designs:

  1. Responses to direct exposures in a range of cell types;
  2. Preconditioning experiments in which a prior dose of chlorogenic acid protected against a subsequent stressor agent;
  3. Studies that included direct exposure, showing hormesis dose responses and then selecting the optimal hormetic dosage as a preconditioning treatment to protect against a subsequent exposure to a toxic agent; and
  4. A mixed group of experiments in which preconditioning was conducted, including several neuronal cellular models, all showing protection against the subsequent exposure to the toxic agent.

However, in the context of translating experimental data to clinical relevance, the concentrations employed in the majority of the in vitro studies with chlorogenic acid far exceeded transitory peak levels, even in heavy coffee drinkers (i.e., approximately 3 μM). In addition to the use of unrealistically high chlorogenic acid concentrations, exposures were prolonged, ranging from 1 to 3 days. These studies are of limited relevance to humans, a similar concern raised by other researchers involved with polyphenol research.


The present paper has framed the hypothesis that key coffee constituents, such as chlorogenic acid, show hormetic effects in a range of cell types and endpoints. Chlorogenic acid may affect some of the health benefits of coffee drinking via its role in GI tract health and beneficial brain-gut interaction.”

https://www.sciencedirect.com/science/article/abs/pii/S0009279724004897 “Do the hormetic effects of chlorogenic acid mediate some of the beneficial effects of coffee?” (not freely available) Thanks to Dr. Evgenios Agathokleous for providing copies of this and the following paper.


A 2024 review by the same research group was on hormetic effects of caffeic acid:

“Caffeic acid is a polyphenol present in numerous fruits and vegetables, especially in coffee. Diets contain about 5–10 to 50 milligrams per day of caffeic acid while coffee ingestion provides about another 250–600 milligrams per day. For the moderate to heavy coffee drinker this would result in an ingestion of about 600–1000 milligrams of caffeic acid from food and coffee consumption.

The present paper evaluates whether caffeic acid may act as an hormetic agent, mediating its chemoprotective effects as has been shown for related agents, such as rosmarinic acid, ferulic acid, and chlorogenic acid. Caffeic acid protective effects were mediated via the upregulation of a series of antioxidant enzymes related to activation of Nrf2.

Caffeic acid enhanced the lifespan of C. elegans along with similar observations for rosmarinic acid that can be hydrolyzed to caffeic acid. Several hundred plant-based agents can enhance lifespan in experimental models such as C. elegans, and there is a competition to find the most effective agents with potential commercial applications.

Hormetic effects typically show a 30 to 60% stimulation above control. This is far below the 2 to 3-fold greater than control detection limit for statistical significance based on human variability/bioplasticity and are often reported as false negatives.

A weight-of-evidence approach was proposed based on multiple in vivo and in vitro test results to derive a study design strategy to increase detection of hormetic effects within the clinical trial framework. Such research should explore hormetic based interactions linking protective catabolic-based adaptive responses with activation and regulation of anabolic mediated hormetic growth effects.”

https://www.tandfonline.com/doi/full/10.1080/19390211.2024.2410776 “Caffeic Acid: Numerous Chemoprotective Effects are Mediated via Hormesis” (not freely available)


A 2024 review provided an overall picture of coffee compounds’ cardiometabolic effects:

“This review provides a comprehensive synthesis of longitudinal observational and interventional studies on the cardiometabolic effects of coffee consumption.

  • Findings indicate that while coffee may cause short-term increases in blood pressure, it does not contribute to long-term hypertension risk.
  • There is limited evidence indicating that coffee intake might reduce the risk of metabolic syndrome and non-alcoholic fatty liver disease.
  • Coffee consumption is consistently linked with reduced risks of type 2 diabetes (T2D) and chronic kidney disease (CKD), showing dose-response relationships.
  • The relationship between coffee and cardiovascular disease is complex, showing potential stroke prevention benefits but ambiguous effects on coronary heart disease.
  • Moderate coffee consumption, typically ranging from 1 to 5 cups per day, is linked to a reduced risk of heart failure, while its impact on atrial fibrillation remains inconclusive. Coffee consumption is associated with a lower risk of all-cause mortality, following a U-shaped pattern, with the largest risk reduction observed at moderate consumption levels.
  • Except for T2D and CKD, Mendelian randomization studies do not robustly support a causal link between coffee consumption and adverse cardiometabolic outcomes.

Potential beneficial effects of coffee on cardiometabolic health are consistent across age, sex, geographical regions, and coffee subtypes and are multi-dimensional, involving antioxidative, anti-inflammatory, lipid-modulating, insulin-sensitizing, and thermogenic effects. Based on its beneficial effects on cardiometabolic health and fundamental biological processes involved in aging, moderate coffee consumption has the potential to contribute to extending healthspan and increasing longevity.”

https://pmc.ncbi.nlm.nih.gov/articles/PMC11493900 “Coffee consumption and cardiometabolic health: a comprehensive review of the evidence”


Polyphenol Nrf2 activators

Two 2024 reviews by the same group that published Sulforaphane in the Goldilocks zone investigated dietary polyphenols’ effects as “hormetic nutrients”:

“Polyphenols display biphasic dose–response effects by activating at a low dose the Nrf2 pathway resulting in the upregulation of antioxidant vitagenes [see diagram]. We aimed to discuss hormetic nutrients, including polyphenols and/or probiotics, targeting the Nrf2 pathway and vitagenes for the development of promising neuroprotective and therapeutic strategies to suppress oxidative stress, inflammation and microbiota deregulation, and consequently improve cognitive performance and brain health.

antioxidants-13-00484-g001

Hormetic nutrition through polyphenols and/or probiotics targeting the antioxidant Nrf2 pathway and stress resilient vitagenes to inhibit oxidative stress and inflammatory pathways, as well as ferroptosis, could represent an effective therapy to manipulate alterations in the gut microbiome leading to brain dysfunction in order to prevent or slow the onset of major cognitive disorders. Notably, hormetic nutrients can stimulate the vagus nerve as a means of directly modulating microbiota-brain interactions for therapeutic purposes to mitigate or reverse the pathophysiological process, restoring gut and brain homeostasis, as reported by extensive preclinical and clinical studies.”

https://www.mdpi.com/2076-3921/13/4/484 “Hormetic Nutrition and Redox Regulation in Gut–Brain Axis Disorders”


I’m not onboard with this study’s probiotic assertions because most of the cited studies contained unacknowledged measurement errors. Measuring gut microbiota, Part 2 found:

“The fecal microbiome does not represent the overall composition of the gut microbiome. Despite significant roles of gut microbiome in various phenotypes and diseases of its host, causative microbes for such characteristics identified by one research fail to be reproduced in others.

Since fecal microbiome is a result of the gut microbiome rather than the representative microbiome of the GI tract of the host, there is a limitation in identifying causative intestinal microbes related to these phenotypes and diseases by studying fecal microbiome.”

These researchers also erroneously equated isothiocyanate sulforaphane’s Nrf2-activating mechanisms with polyphenols activating Nrf2.


This research group did better in clarifying polyphenols’ mechanisms in a review of hormetic dose-response effects of the polyphenol rosmarinic acid:

“This article evaluates whether rosmarinic acid may act as a hormetic agent, mediating its chemoprotective effects as has been shown for similar agents, such as caffeic acid, a derivative of rosmarinic acid.

Rosmarinic acid enhanced memory in institute of cancer research male mice in the Morris water maze (escape latency).

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Of importance in the evaluation of rosmarinic acid are its bioavailability, metabolism, and tissue distribution (including the capacity to affect and/or cross the BBB and its distribution and half-life within the brain). In the case of polyphenols, including rosmarinic acid, they are typically delivered at low doses in the diet and, in most instances, they do not escape first-pass metabolism, with the prominent chemical forms being conjugates of glucuronides and sulfates, with or without methylation.

These conjugated metabolites are chemically distinct from the parent compound, showing considerable differences in size, polarity, and ionic form. Their biological actions are quite different from the parent compound.

Bioavailability studies reveal that maximum concentrations in plasma typically do not exceed 1 µM following consumption of 10–100 mg of a single phenolic compound, with the maximum concentration occurring typically less than 2 h after ingestion, then dropping quickly thereafter. In the case of the in vitro studies assessed herein, and with few exceptions, most of the studies employed concentrations >10 µM with some studies involving concentrations in the several hundred µM range, with the duration of exposure typically in the range of 24–72 h, far longer duration than the very short time interval of a few minutes to several hours in human in vivo situations.

We strongly recommend that all experiments using in vitro models to study biological responses to dietary polyphenols use only physiologically relevant flavonoids and their conjugates at appropriate concentrations, provide evidence to support their use, and justify any conclusions generated. When authors fail to do this, referees and editors must act to ensure that data obtained in vitro are relevant to what might occur in vivo.”

https://www.degruyter.com/document/doi/10.1515/med-2024-1065/html “The chemoprotective hormetic effects of rosmarinic acid”

An elevator pitch for plasmalogen precursors

An excerpt from the latest video at Dr. Goodenowe’s Health Matters podcast, Episode 7 “The Truth about Parkinson’s”, starting at 50:30:

“What’s exciting about this community medicine focus that we’ve switched to which basically says: How do we develop technologies in a way that they can be incorporated into a community model versus a pharmaceutical drug model? People can actually do I would say self-experiment just the way you self-experiment with your own diet because these are fundamentally dietary nutrition molecules.

Could you give me an elevator pitch because there are probably people listening who are thinking what is this plasmalogen precursor and for sure how is it having this dramatic effect?

Plasmalogens are the most important nutrient that nobody knows about. Normally you don’t know about it because the body is usually pretty good at making them. What makes plasmalogens unique is that your body makes them kind of like cannon fodder, the first group of people that go into war. Your body throws them out for destruction. They absorb oxidative stress and get destroyed in the process.

They’re stored in your cell membranes. 50% of the membranes of your heart are these plasmalogen molecules. When your heart gets inflamed, what your heart does is it dumps these plasmalogens out of its membranes to douse the flame of inflammation. After inflammation is under control, your body naturally builds these things back up again.

But if you have an inability to make enough plasmalogens, these inflammation events knock you down and keep you down. So plasmalogen precursors are critical for maintaining high levels of plasmalogens across your body, not just in your brain (30% of the lipids in your brain) but in your heart, your lungs, your kidneys.”


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Take acetyl-L-carnitine if you are healthy

Eight 2023 acetyl-L-carnitine / L-carnitine papers, starting with three healthy human studies:

“Thirty healthy volunteers aged between 19 and 52 years were divided randomly into two equal groups, one of which received 1000 mg of L-carnitine (LC) per day over a 12-week period. Total cholesterol and HDL-C increased significantly after supplementation. LC could be useful in impeding development of heart diseases in subjects with low HDL-C.”

https://journaljammr.com/index.php/JAMMR/article/view/5166 “L-Carnitine Increases High Density Lipoprotein-Cholesterol in Healthy Individuals: A Randomized Trial”

Rationale for dose selection wasn’t provided, and the possibility of limited results due to poor study design wasn’t mentioned.


“This study examined effects of 12 weeks of LC supplementation on bone mineral density (BMD) and selected blood markers involved in bone metabolism of postmenopausal women participating in a resistance training (RT) program. Participants’ diets were supplemented with either 1 g of LC-L-tartrate and 3 g of leucine per day (LC group) or 4 g of leucine per day as a placebo (PLA group), in a double-blind fashion.

Because the study protocol consisted of both exercise and supplementation, some favorable changes in the BMD could be expected. However, it was not possible to detect them in the short study period. No significant modification in BMDs of the spine, hip, and total skeleton and no differences between groups in one-repetition maximum could be due to the relatively short duration of the RT intervention.”

https://nutritionandmetabolism.biomedcentral.com/articles/10.1186/s12986-023-00752-1 “Effect of a 3-month L-carnitine supplementation and resistance training program on circulating markers and bone mineral density in postmenopausal women: a randomized controlled trial”

Same comments as the first study regarding no rationale for dose selection, and no mention that limited results were possibly due to an inadequate dose.


In a letter to the editor, a researcher took issue with a study’s methodology:

“Based on finding that intravenous provision with carnitine alone does not increase muscle carnitine accretion, and on the above-reevaluated data, it appears that the basis for carnitine with caffeine being able to increase muscle carnitine levels, and thereby manipulation of muscle metabolism and exercise performance, is uncertain.

Carnitine bioavailability in any group would have been 9.5%. This assessment would be in line with previously recorded values of 5%–18% carnitine bioavailability. It is firmly believed that low carnitine bioavailability is attributable to the inability of kidneys to reabsorb carnitine when the threshold concentration for tubular reabsorption (about 40–60 μmol/L) has passed this value.

The authors’ proposed long-term use of carnitine supplementation as an aid to improve fat oxidation in type II diabetes also seems to lack provision.”

https://physoc.onlinelibrary.wiley.com/doi/10.14814/phy2.15736 “LTE: Does caffeine truly raise muscle carnitine in humans?”


Two genetic studies:

“Our findings suggest that humans have lost a gene involved in carnitine biosynthesis. Hydroxytrimethyllysine aldolase (the second enzyme of carnitine biosynthesis) activity of serine hydroxymethyl transferase partially compensates for its function.”

https://www.researchsquare.com/article/rs-3295520/v1 “One substrate-many enzymes virtual screening uncovers missing genes of carnitine biosynthesis in human and mouse”


“Reported prevalence of primary carnitine deficiency (PCD) in the Faroe Islands of 1:300 is the highest in the world. The Faroese PCD patient cohort has been closely monitored and we now report results from a 10-year follow-up study of 139 PCD patients.

PCD is an autosomal recessive disorder that affects the function of organic cation transporter 2 (OCTN2) high-affinity carnitine transporters, that localizes to the cell membrane and transport carnitine actively inside the cell. Without proper functioning OCTN2 carnitine transporters, renal reabsorption of carnitine is impaired, and as a consequence, patients suffering from PCD have low plasma levels of carnitine. This can disturb cellular energy production and cause fatigue, but also in extreme cases lead to cellular dysfunction and severe symptoms of coma and sudden death.

PCD patients seem to adhere well to L-carnitine treatment, even though they have to ingest L-carnitine tablets at least three times a day. Overall mean L-carnitine dosage was 66.3 mg/kg/day.”

https://onlinelibrary.wiley.com/doi/10.1002/jmd2.12383 “Patients with primary carnitine deficiency treated with L-carnitine are alive and doing well—A 10-year follow-up in the Faroe Islands”

The average daily dose is (66.3 mg x 70 kg) = 4,641 mg. A third of this dose would be about 1.5 g.

The first study of Acetyl-L-carnitine dosing also suggested dosing L-carnitine three times a day because of 10-20% bioavailability.


A study with unhealthy humans:

“This retrospective study analyzed medical records of adult patients between March 2007 and April 2019, with presenting complaints of fatigue and lethargy. Acetyl-L-carnitine has physiological functions similar to L-carnitine but has higher bioavailability and antioxidant properties. This study confirmed that a triple combination therapy with γ-linolenic acid, V. vinifera extract, and acetyl-L-carnitine can improve arterial stiffness in patients.

Our study had some limitations:

  1. The study population may not be representative of the entire Korean adult population.
  2. The study did not have a medication-free control group. Instead, the comparison group comprised patients with medication compliance <80%.
  3. Drop-out rate of the triple-combination therapy (46.2%, 147/318) was relatively high, indicating the possibility of bias due to loss to follow-up.
  4. The study did not consider lifestyle factors such as smoking, diet, and physical activity level, which may affect arterial stiffness.
  5. The study did not examine interactions among drugs comprising the combination therapy, although all drugs are known to positively impact blood vessels.”

https://onlinelibrary.wiley.com/doi/10.1111/jch.14708 “Efficacy of γ-linolenic acid, Vitis vinifera extract, and acetyl-L-carnitine combination therapy for improving arterial stiffness in Korean adults: Real-world evidence”

This study’s acetyl-L-carnitine dose was 500 mg three times a day.


Wrapping up with two rodent studies:

“Acetyl L-carnitine (ALCAR) has proved useful in treatment of different types of chronic pain with excellent tolerability. The present work aimed at evaluating the anti-hyperalgesic efficacy of ALCAR in a model of persistent visceral pain associated with colitis.

The acetyl group in the ALCAR molecule can enhance cholinergic signalling by promoting synthesis of neurotransmitter acetylcholine, which plays an important role in both the enteric and central nervous systems. Acetylcholine signalling has significant antinociceptive effects in development of visceral pain, so it has been proposed as a therapeutic target.

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ALCAR significantly reduced establishment of visceral hyperalgesia in DNBS-treated animals, though the interventive protocol showed a greater efficacy than the preventive one.

  • The interventive protocol partially reduced colon damage in rats, counteracting enteric glia and spinal astrocyte activation resulting from colitis.
  • The preventive protocol effectively protected enteric neurons from inflammatory insult.

These findings suggest the putative usefulness of ALCAR as a food supplement for patients suffering from inflammatory bowel diseases.”

https://www.mdpi.com/1422-0067/24/19/14841 “Anti-Hyperalgesic Efficacy of Acetyl L-Carnitine (ALCAR) Against Visceral Pain Induced by Colitis: Involvement of Glia in the Enteric and Central Nervous System

This study cited multiple animal studies that found acetyl-L-carnitine was effective for different types of pain. I’ve taken it every day for nineteen years, and haven’t noticed that effect.


“Repetitive mild traumatic brain injuries (rmTBI) may contribute to development of neurodegenerative diseases through secondary injury pathways. Acetyl-L-carnitine (ALC) shows neuroprotection through anti-inflammatory effects, and via regulation of neuronal synaptic plasticity by counteracting post-trauma excitotoxicity. This study aimed to investigate mechanisms implicated in etiology of neurodegeneration in rmTBI mice treated with ALC.

ALC is an endogenously produced carnitine metabolite present in tissue and plasma, and readily crosses the blood brain barrier, unlike its unacetylated form. ALC is also a commonly available nutritional supplement, with a known safety profile, and had been well-studied for its role in aiding β-oxidation of long chain fatty acids in the mitochondria.

While some studies have shown promise for improving clinical and psychometric outcomes in individuals with probable Alzheimer’s disease (AD) and mild cognitive impairment, other studies that included participants with moderate AD progression were less conclusive. It may be that this lack of improvement is related to a therapeutic window of opportunity. Once neurodegenerative mechanisms have commenced, a reversal of these processes is not attainable.

There is currently a lack of evidence for safe therapeutics that can be administered long-term to reduce the risk of individuals developing cognitive and neuropsychological deficits after rmTBIs. Prophylactic ALC treatment in a paradigm of neurotrauma may be a way to maximize its therapeutic potential.

While brain structures display differential vulnerability to insult as evidenced by location specific postimpact disruption of key genes, this study shows correlative mRNA neurodegeneration and functional impairment that was ameliorated by ALC treatment in several key genes. ALC may mitigate damage inflicted in various secondary neurodegenerative cascades – confirmed by improvements in behavioral and cognitive function – and contribute to functional protection following rmTBI.”

https://www.frontiersin.org/articles/10.3389/fphar.2023.1254382/full “Repetitive mild traumatic brain injury-induced neurodegeneration and inflammation is attenuated by acetyl-L-carnitine in a preclinical model”

I read many traumatic brain injury papers earlier this year, but only curated two in Brain endothelial cells. I came away thinking that there’s no permanent recovery from TBIs, as just symptoms are effectively treated.

Most TBIs happen to old people who have diminished brain reserves. I didn’t see studies that factored in evidence of what happened earlier in injured people’s lives that created TBI susceptibility but wasn’t remembered.

Unlike other years, I haven’t watched any football this season. It’s unsettling that transient entertainment value continues to take precedence over permanent effects on players’ lives.


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Brain restoration with plasmalogens

In this 2023 presentation for a professional audience, Dr. Dayan Goodenowe showed an example of what could be done (in the form of what he personally did at ages 53-54) to restore and augment brain structure and function over a 17-month period by taking plasmalogens and supporting supplements:

https://drgoodenowe.com/recording-of-dr-goodenowes-presentation-from-the-peptide-world-congress-2023-is-now-available/

Follow the video along with its interactive transcript. Restorative / augmentative supplements included:

1. Nutritional Supplementation Strategy

Forms of MRI used to document brain structure and function changes were:

2. Advanced MRI Technologies

Brain volume decreases are the rule for humans beginning at age 40. Dr. Goodenowe documented brain volume increases, which aren’t supposed to happen, but did per the below slide of overall results:

3. Reversing Brain Shrinkage

“From a global cortical volume and thickness perspective, 17 months of high-dose plasmalogens reversed ~15 years of predicted brain deterioration.”


Specific increased adaptations in brain measurements over 17 months included:

  1. Cortical thickness .07/2.51 = +3%.
  2. White matter microstructure fractional anisotropy +8%.
  3. Nucleus accumbens volume +30%.
  4. Dopaminergic striatal terminal fields’ volume +18%.
  5. Cholinergic cortical terminal fields’ volume +10%.
  6. Occipital cortex volume +10%.
  7. Optic chiasm volume +225%.
  8. Nucleus basalis connectivity.
  9. Neurovascular coupling signal controlled by noradrenaline integrity.
  10. Amygdala volume +4% and its connectivity to the insula, indicating ongoing anxiety and emotional stress response.
  11. Parahippocampus volume +7%.
  12. Hippocampus fractional anisotropy +5%.

No changes:

  1. Amygdala connectivity to the ventral lateral prefrontal cortex, the same part of the brain that relates to placebo effect.
  2. Hippocampus connectivity.

Decreased adaptations in brain measurements included:

  1. White matter microstructure radial diffusivity -10%.
  2. Amygdala connectivity to the anterior cingulate cortex to suppress / ignore / deny anxiety response.
  3. Amygdala connectivity to the dorsal lateral prefrontal cortex.
  4. Entorhinal cortex volume -14%.
  5. Hippocampus volume -6%.
  6. Hippocampus mean diffusivity (white matter improved, with more and tighter myelin) -4%.

The other half of this video was a lively and wide-ranging Q&A session.


The referenced 2023 study of 653 adults followed over ten years showed what brain deterioration could be expected with no interventions. Consider these annual volume decrease rates to be a sample of a control group:

etable 3

https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2806488 “Characterization of Brain Volume Changes in Aging Individuals With Normal Cognition Using Serial Magnetic Resonance Imaging”

Also see a different population’s brain shrinkage data in Prevent your brain from shrinking.


The daily plasmalogen precursor doses Dr. Goodenowe took were equivalent to 100 mg softgel/kg, double the maximum dose of 50 mg softgel/kg provided during the 2022 clinical trial of cognitively impaired old people referenced in Plasmalogens Parts 1, 2, and 3.

He mentions taking 5 ml in the morning and 5 ml at night because he used the Prodrome oil products. 1 ml of a Prodrome oil plasmalogen precursor product equals 900 mg of their softgel product.


“My brain is trying to minimize long-term effects of pain/stress by suppressing my memory of it. But this can only go on for so long before it becomes an entrenched state.

I have solved the sustenance side of the equation. I need to work harder to solve the environmental side.”

While I agree that we each have a responsibility to ourselves to create an environment that’s conducive to our health, the above phenomenon isn’t necessarily resolvable by changing an individual’s current environment. My understanding is that long-term effects of pain, stress, and related human experiences are usually symptoms of causes that started much earlier in our lives.

Adjusting one’s present environment may have immediate results, but probably won’t have much therapeutic impact on long-term issues. Early life memories and experiences are where we have to gradually go in order to stop being driven by what happened back then.

See Dr. Arthur Janov’s Primal Therapy for its principles and explanations. I started Primal Therapy at a similar age, 53, and continued for three years.


Continued with Part 2.

The brain-gut-lung circuit

This 2023 rodent study investigated mechanisms of improving stress-worsened respiratory viral infection:

“Our study demonstrates that chronic psychological stress significantly increases host vulnerability to influenza A virus (IAV) infection characterized by a distorted gut microbiome and deregulated alveolar macrophages (AMs) response. We show that microbiome-derived γ-aminobutyric acid (GABA) functions as a tonic signal to support survival, self-renewing, and immunoregulation of AMs, and hence optimized pulmonary defensive response.

Chronic psychological stress causes gut microbiome dysbiosis and defective GABA generation, leading to loss of AMs homeostasis and aggravated viral pneumonia. The data indicate that:

  1. Microbial GABA is released in the circulation,
  2. Sensed by AMs via the GABAA receptor,
  3. Promoting cellular mitochondrial metabolism,
  4. For increased production of α-ketoglutarate (αKG),
  5. Which triggers Tet2-mediated DNA hydroxymethylation,
  6. To enable PPARγ-centered gene program,
  7. Supporting AMs homeostasis and function.

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  • Re-localization of GABA-generating probiotics,
  • Supplementation of αKG, or
  • Adoptive transfer of GABA-conditioned macrophages,
  • Substantially rectifies stress-induced disruption inter-organ communication, and
  • Alleviates symptoms of viral pneumonia.

Our current study unveils an unappreciated regulatory circuitry that connects the brain, gut, and lung to mediate neurological modulation of host defensive response.”

https://www.sciencedirect.com/science/article/pii/S2090123223001716 “Gut microbial GABAergic signaling improves stress-associated innate immunity to respiratory viral infection”


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A biomarker for impaired cognitive function?

This 2023 rodent study investigated associations between a drug, a gut microbiota species, cognitive function, and proinflammatory cytokine interleukin-6:

“We show that gut microbiota is altered by metformin, which is necessary for protection against ageing-associated cognitive function declines in aged mice.

  • Mice treated with antibiotics did not exhibit metformin-mediated cognitive function protection.
  • Treatment with Akkermansia muciniphila improved cognitive function in aged mice.
  • A. muciniphila decreased proinflammatory-associated pathways, particularly that of proinflammatory cytokine interleukin (IL)-6, in both peripheral blood and hippocampal profiles, which was correlated with cognitive function improvement.
  • An IL-6 antibody protected cognitive function, and an IL-6 recombinant protein abolished the protective effect of A. muciniphila on cognitive function in aged mice.

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A. muciniphila, which is mediated in gut microbiota by metformin, modulates inflammation-related pathways in the host and improves cognitive function in aged mice by reducing proinflammatory cytokine IL-6 both systemically and in the hippocampus. This is direct evidence to validate that gut microbiota mediate the effect of metformin on cognitive improvement.”

https://microbiomejournal.biomedcentral.com/articles/10.1186/s40168-023-01567-1Akkermansia muciniphila, which is enriched in the gut microbiota by metformin, improves cognitive function in aged mice by reducing the proinflammatory cytokine interleukin-6″


IL-6 may be useful with other biomarkers of impaired cognitive function. It’s too coarse to track improved cognitive function past a certain point, though. Maybe the current IL-6 blood test can be refined as high-specificity CRP and regular CRP blood tests were done?

We don’t need to take this drug or be concerned about this gut bacteria species in order to lower inflammation. Click the IL-6 link above and see blog posts such as Part 2 of Rejuvenation therapy and sulforaphane for other methods.

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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 limited bedding and nesting (LBN) and maternal separation (MS) paradigms. We then tested whether predictability of 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.”

https://www.sciencedirect.com/science/article/pii/S2352289522000595 “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 inherent stability of this epigenomic marker – it is dynamic and potentially reversible.”

https://www.tandfonline.com/doi/full/10.31887/DCNS.2005.7.2/mmeaney “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.


Our lives are substantially a product of our parents’ actualized and unsatisfied needs. Our children and their children are reflections of us with our problems (unfelt needs) or elucidations (felt needs).

What if the price we pay for avoiding and pressuring down our feelings is: A wasted life?

What if the grand hypothesis worth proving is: For one’s life to have meaning, each individual has to regain their feelings?

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Minds of their own

It’s the weekend, so it’s time for: Running errands? Watching sports? Other conditioned behavior?

Or maybe broadening our cognitive ability with Dr. Michael Levin’s follow-ups to his 2021 Basal cognition paper and 2020 Electroceuticals presentation with a 2022 paper and presentation starting around the 13:30 mark:

Michael Levin - Cell Intelligence in Physiological and Morphological Spaces

“A homeostatic feedback is usually thought of as a single variable such as temperature or pH. The set point has been found to be a large-scale geometry, a descriptor of a complex data structure.”


His 2022 paper Technological Approach to Mind Everywhere: An Experimentally-Grounded Framework for Understanding Diverse Bodies and Minds:

“It is proposed that the traditional problem-solving behavior we see in standard animals in 3D space is just a variant of evolutionarily more ancient capacity to solve problems in metabolic, physiological, transcriptional, and morphogenetic spaces (as one possible sequential timeline along which evolution pivoted some of the same strategies to solve problems in new spaces).

Developmental bioelectricity works alongside other modalities such as gene-regulatory networks, biomechanics, and biochemical systems. Developmental bioelectricity provides a bridge between the early problem-solving of body anatomy and the more recent complexity of behavioral sophistication via brains.

This unification of two disciplines suggests a number of hypotheses about the evolutionary path that pivoted morphogenetic control mechanisms into cognitive capacities of behavior, and sheds light on how Selves arise and expand.

While being very careful with powerful advances, it must also be kept in mind that existing balance was not achieved by optimizing happiness or any other quality commensurate with modern values. It is the result of dynamical systems properties shaped by meanderings of the evolutionary process and the harsh process of selection for survival capacity.”


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Gut microbiota, SCFAs, and hypertension

Two 2022 rodent studies from the same research group on short-chain fatty acid effects, beginning with butyrate:

“Maternal nutrition, gut microbiome composition, and metabolites derived from gut microbiota are closely related to development of hypertension in offspring. A plethora of metabolites generated from diverse tryptophan metabolic pathways show both beneficial and harmful effects.

Butyrate, one of the short-chain fatty acids (SCFAs), has shown vasodilation effects. We examined whether sodium butyrate administration in pregnancy and lactation can prevent hypertension induced by a maternal tryptophan-free diet in adult progeny, and explored protective mechanisms.

Decreased tryptophan metabolites indole-3-acetamide and indoleacetic acid observed in offspring born to dams that received the trytophan-free (TF) diet coincided with hypertension. This suggested that gut microbiota-derived tryptophan metabolites might be an offsetting mechanism, but not a cause of TF-induced hypertension. Considering that TF intervention reduced abundance of Romboutsia and Akkermansia, and many species are able to metabolize tryptophan, further studies linking abundance of bacterial species and concentrations of tryptophan metabolites are still required to identify main tryptophan metabolite producers.

Sodium butyrate treatment during pregnancy and lactation offset effects of maternal tryptophan-deficiency-induced offspring hypertension, mainly related to shaping gut microbiome, mediating SCFA receptor GPR41 and GPE109A, and restoring the renin–angiotensin system. A better understanding of mechanisms behind tryptophan metabolism implicated in programming of hypertension is critical for developing gut microbiota-targeted therapies to halt hypertension.”

https://www.sciencedirect.com/science/article/abs/pii/S0955286322001619 “Sodium butyrate modulates blood pressure and gut microbiota in maternal tryptophan-free diet-induced hypertension rat offspring” (not freely available) Thanks to Dr. You-Lin Tain for providing a copy.


A second study was on propionate effects:

“Early-life disturbance of gut microbiota has an impact on adult disease in later life. Propionate, one of predominant SCFAs, has been shown to have antihypertensive property.

We examined whether perinatal propionate supplementation can prevent offspring hypertension induced by maternal chronic kidney disease (CKD). CKD is closely linked to adverse maternal and fetal outcomes, and is reported to affect at least 3%-4% women of childbearing age.

Male offspring were divided into four groups: control, CKD, control+propionate (CP), and CKD+propionate (CKDP).

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Perinatal propionate supplementation:

  • Prevented offspring hypertension;
  • Shaped gut microbiota with increases in species richness and evenness;
  • Increased plasma propionate level; and
  • Upregulated renal GPR41 expression.

Results reveal the feasibility of manipulating gut microbiota by altering their metabolites with early-life use of propionate to prevent offspring hypertension in later life.”

https://www.mdpi.com/2072-6643/14/16/3435/htm “Perinatal Propionate Supplementation Protects Adult Male Offspring from Maternal Chronic Kidney Disease-Induced Hypertension”


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Glucoraphanin is not sulforaphane

A poorly-conceived and intentionally-misrepresented human 2022 broccoli product study:

“We investigated whether a sulforaphane (SFN) [actually, sulforaphane precursor glucoraphanin] intake intervention improved cognitive performance and mood states in healthy older adults in a 12-week, double-blinded, randomized controlled trial.

The SFN group showed improvement in processing speed and a decrease in negative mood compared to the placebo group. However, there were no significant results in other biomarkers of oxidant stress, inflammation, or neural plasticity.

These results indicate that nutrition interventions using SFN can have positive effects on cognitive functioning and mood in healthy older adults.”

https://www.frontiersin.org/articles/10.3389/fnagi.2022.929628/full “Effects of sulforaphane intake on processing speed and negative moods in healthy older adults: Evidence from a randomized controlled trial”


Contrary to this study’s title, actual sulforaphane intake was not measured. The glucoraphanin product used in this study was the same item and daily dose as Eat broccoli sprouts for your workouts, which investigated effects with 19-to-23-year-old men. The treatment was taken all at once at an unspecified time of day rather than three times a day with young subjects.

These researchers knew from the 2012 study cited for dose that:

“Individual conversions of glucosinolates [like glucoraphanin] to isothiocyanates [like sulforaphane] varied enormously, from about 1% to more than 40% of dose. In contrast, administration of isothiocyanates (largely sulforaphane)-containing broccoli sprout extracts, resulted in uniformly high (70-90%) conversions to urinary dithiocarbamates.”

Young or old, a daily 30 mg glucoraphanin intake isn’t sufficient to fully activate human Nrf2 signaling pathways. A daily 17 mg sulforaphane intake could accomplish that.


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Non-patentable boron benefits

To follow up Is boron important to health? I’ll highlight a 2022 review of boron intake:

“Boron is essential for activity of several metabolic enzymes, hormones, and micronutrients. It is important for growth and maintenance of bone, reduction in inflammatory biomarkers, and increasing levels of antioxidant enzymes.

The average person’s daily diet contains 1.5 to 3 milligrams of boron. Boron intakes of 1–3 mg/day have been shown to improve bone and brain health in adults when compared to intakes of 0.25–0.50 mg/day.

One week of 10 mg/d boron supplementation resulted in a 20% reduction in inflammatory biomarkers TNF-α, as well as significant reductions (nearly 50%) in plasma concentrations of hs-CRP and IL-6. Calcium fructoborate, a naturally occurring, plant-based boron-carbohydrate complex, had beneficial effects on osteoarthritis (OA) symptoms. A double-blind study in middle-aged patients with primary OA found that all groups except the placebo group saw a reduction in inflammatory biomarkers after 15 days of food supplementation with calcium fructoborate.

Dietary boron intake significantly improves brain function and cognitive functioning in humans. Electroencephalograms showed that boron pharmacological intervention after boron deficiency improved functioning in older men and women, such as less drowsiness and mental alertness, better psychomotor skills (for example, motor speed and dexterity), and better cognitive processing (e.g., attention and short-term memory). Boron compounds can help with both impaired recognition and spatial memory problems.

We discussed the role of boron-based diet in memory, boron and microbiome relation, boron as anti-inflammatory agents, and boron in neurodegenerative diseases. Boron reagents will play a significant role to improve dysbiosis.”

https://www.mdpi.com/1420-3049/27/11/3402/htm “The Role of Microbiome in Brain Development and Neurodegenerative Diseases”


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