This dietary supplement is better for depression symptoms than placebo

This 2018 Italy/UK meta-analysis subject was the use of dietary supplement acetyl-L-carnitine to treat depression symptoms:

“Deficiency of acetyl-L-carnitine (ALC) appears to play a role in the risk of developing depression, indicating dysregulation of fatty acids transport across the inner membrane of mitochondria. However, the data regarding ALC supplementation in humans are limited. We thus conducted a systematic review and meta-analysis investigating the effect of ALC on depressive symptoms across randomized controlled trials (RCTs).

Pooled data across nine RCTs (231 treated with ALC versus 216 treated with placebo and 20 no intervention) showed that ALC significantly reduced depressive symptoms.

In these nine RCTs, the majority of the studies used 3 grams of ALC as intervention.

In three RCTs comparing ALC versus antidepressants (162 for each group), ALC demonstrated similar effectiveness compared with established antidepressants [fluoxetine (Prozac), duloxetine (Cymbalta), amisulpride (Solian) respectively below] in reducing depressive symptoms. In these latter RCTs, the incidence of adverse effects was significantly lower in the ALC group [79%] than in the antidepressant group.

Subgroup analyses suggested that ALC was most efficacious in older adults. Future large scale trials are required to confirm/refute these findings.”

From the Methods section:

“Studies were excluded if:

  1. did not include humans;
  2. did not include a control group;
  3. did not use validated scales for assessing depression;
  4. did not report data at follow-up evaluation regarding tests assessing depression;
  5. included the use of ALC with another agent vs. placebo/no intervention.”

The Discussion section was informative regarding possible mechanisms of ALC affecting depression, pain, and linked symptoms. Several citations were of a review rather than of the original studies, however.


Research needs to proceed on to investigate therapies that address ultimate causes for depression and pain. Researchers and sponsors shouldn’t stop at just symptoms and symptom relief, notwithstanding the requirement from a statistical point of view for “future large scale trials.”

Here are other acetyl-L-carnitine topics I’ve curated:

https://journals.lww.com/psychosomaticmedicine/Citation/2018/02000/Acetyl_L_Carnitine_Supplementation_and_the.4.aspx “Acetyl-L-Carnitine Supplementation and the Treatment of Depressive Symptoms: A Systematic Review and Meta-Analysis” (not freely available)


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Sex-specific impacts of childhood trauma

This 2018 Canadian paper reviewed evidence for potential sex-specific differences in the lasting impacts of childhood trauma:

“This paper will provide a contextualized summary of neuroendocrine, neuroimaging, and behavioral epigenetic studies on biological sex differences contributing to internalizing psychopathology, specifically posttraumatic stress disorder and depression, among adults with a history of childhood abuse.

Given the breadth of this review, we limit our definition [of] trauma to intentional and interpersonal experiences (i.e., childhood abuse and neglect) in childhood. Psychopathological outcomes within this review will be limited to commonly explored internalizing disorders, specifically PTSD and depression.

Despite the inconsistent and limited findings in this review, a critical future consideration will be whether the biological effects of early life stress can be reversed in the face of evidence-based behavioral interventions, and furthermore, whether these changes may relate to potentially concurrent reductions in susceptibility to negative mental health outcomes.”


It was refreshing to read a paper where the reviewers often interrupted the reader’s train of thought to interject contradictory evidence, and display the scientific method. For example, immediately after citing a trio of well-respected studies that found:

“Psychobiological research on relationships linking impaired HPA axis functioning and adult internalizing disorders are suggestive of lower basal and afternoon levels of plasma cortisol in PTSD phenotype.”

the reviewers stated:

“However, a recent meta-analysis suggests no association between basal cortisol with PTSD.”

and effectively ended the cortisol discussion with:

“Findings are dependent upon variance in extenuating factors, including but not limited to, different measurements of:

  • early adversity,
  • age of onset,
  • basal cortisol levels, as well as
  • trauma forms and subtypes, and
  • presence and severity of psychopathology symptomology.”

The reviewers also provided good summaries of aspects of the reviewed subject. For example, the “Serotonergic system genetic research, childhood trauma and risk of psychopathology” subsection ended with:

“Going forward, studies must explore the longitudinal effects of early trauma on methylation as well as comparisons of multiple loci methylation patterns and interactions to determine the greatest factors contributing to health outcomes. Only then, can we start to consider the role of sex in moderating risk.”


I didn’t agree with the cause-ignoring approach of the behavior therapy mentioned in the review. Does it make sense to approach one category of symptoms:

“the biological effects of early life stress”

by treating another category of symptoms?

“can be reversed in the face of evidence-based behavioral interventions.”

But addressing symptoms instead of the sometimes-common causes that generate both biological and behavioral effects continues to be the direction.

After receiving short-term symptom relief, wouldn’t people prefer treatments of originating causes so that their various symptoms don’t keep bubbling up? Why wouldn’t research paradigms be aligned accordingly?

I was encouraged by the intergenerational and transgenerational focus of one of the reviewer’s research:

“Dr. Gonzalez’s current research focus is to understand the mechanisms by which early experiences are transmitted across generations and how preventive interventions may affect this transmission.”

This line of hypotheses requires detailed histories, and should uncover causes for many effects that researchers may otherwise shrug off as unexplainable individual differences. Its aims include the preconception through prenatal periods when both the largest and the largest number of epigenetic changes occur, and is when our susceptibility and sensitivity to our environment is greatest. There are fewer opportunities for effective “preventive interventions” in later life compared with these early periods.

Unlike lab rats, women and men can reach some degree of honesty about our early lives’ experiential causes of ongoing adverse effects. Experiential therapies that allow humans to potentially change their responses to these causes deserve more investigation than do therapies that apply external “interventions.”

https://www.sciencedirect.com/science/article/pii/S0272735817302647 “Biological alterations affecting risk of adult psychopathology following childhood trauma: A review of sex differences” (not freely available) Thanks to lead author Dr. Ashwini Tiwari for providing a copy.

Epigenetic mechanisms of muscle memory

This 2018 UK human study detailed epigenetic muscle memory:

“We aimed to investigate an epigenetic memory of earlier hypertrophy in adult human skeletal muscle using a within measures design, by undertaking:

  1. Resistance exercise induced muscle growth (loading) [3 days a week for 7 weeks], followed by;
  2. Cessation of resistance exercise, to return muscle back towards baseline levels (unloading) [7 weeks], and;
  3. A subsequent later period of resistance exercise induced muscle hypertrophy (reloading) [3 days a week for 7 weeks].”

The findings were:

“Frequency of genome-wide hypomethylation is the largest after reloading induced hypertrophy where lean muscle mass is enhanced.

Hypomethylation is maintained from earlier load induced hypertrophy even during unloading where muscle mass returns back towards baseline, and is inversely associated with gene expression.

A single bout of acute resistance exercise evokes hypomethylation of genes that have enhanced gene expression in later reload induced hypertrophy.”

https://www.nature.com/articles/s41598-018-20287-3 “Human Skeletal Muscle Possesses an Epigenetic Memory of Hypertrophy”


The study provided another example of how our bodies remember. It began with only eight male 27.6 ± 2.4 year-old subjects, though, and one of them dropped out.

See the discussion of a 2017 Netherlands human study in Are Underpowered Studies Ever Justified? with comments on studies with few subjects, such as:

“The problem occurs when people do small quantitative studies, but draw conclusions nonetheless, simply adding a disclaimer to the discussion (which they don’t put in the abstract, or the press release).”

“Underpowered studies may only be useful to check if the experiment works out wrt understanding instructions, do the programs run, etc, but not as much for testing and estimating effects.”

“The problem with underpowered studies is that all estimates can vary erratically between samples. Combined with the desire of many researchers (and universities’ press offices) to find sensational patterns, this means that evidence from underpowered studies is ‘asymmetrically’ likely to be considered more conclusive. As in, something that seems really cool will probably be considered more conclusive than something that’s disappointing. Highly powered studies don’t afford this flexibility.”

Transgenerational effects of early environmental insults on aging and disease

The first paper of Transgenerational epigenetic inheritance week was a 2017 Canadian/Netherlands review that’s organized as follows:

“First, we address mechanisms of developmental and transgenerational programming of disease and inheritance. Second, we discuss experimental and clinical findings linking early environmental determinants to adverse aging trajectories in association with possible parental contributions and sex-specific effects. Third, we outline the main mechanisms of age-related functional decline and suggest potential interventions to reverse negative effects of transgenerational programming.”

A transgenerational phenotype was defined as an epigenetic modification that was maintained at least either to F2 grandchildren in the paternal lineage, or to F3 great-grandchildren in the maternal lineage.

The reviewers noted that mechanisms of transgenerational programming are complex and multivariate.  Severity, timing, and type of exposure; lineage of transmission; germ cell exposure; and gender of an organism were the main factors that may determine consequences. Mechanisms reviewed were:

  1. Parental exposure to an adverse environment;
  2. Altered maternal behavior and care of offspring; and
  3. Experience-dependent modifications of the epigenome.

There was a long list of diseases and impaired functionalities that were consequences of ancestral experiences and exposures. Most studies were of animals, but a few were human, such as those done on effects of extended power outages during a Quebec ice storm of January 1998.


One intervention that was effective in reversing a transgenerational phenotype induced by deficient rodent maternal care was to place pups with a caring foster female soon after birth. It’s probably unacceptable in human societies to preemptively recognize all poor-care human mothers and remove the infant to caring foster mothers. But researchers could probably find enough instances to develop studies of the effectiveness of such placements in reversing a transgenerational phenotype.

The review didn’t have suggestions for reversing human transgenerational phenotypes, just “potential interventions to reverse negative effects of transgenerational programming.” Interventions suggested for humans – exercise, enriched lifestyle, cognitive training, dietary regimens, and expressive art and writing therapies – only reduced impacts of transgenerational epigenetic effects.

Tricky wording of “reverse negative effects of transgenerational programming” showed that research paradigms weren’t aimed at resolving causes. The review was insufficient for the same reasons mentioned in How one person’s paradigms regarding stress and epigenetics impedes relevant research, prompting my same comment:

Aren’t people interested in human treatments of originating causes so that their various symptoms don’t keep bubbling up? Why wouldn’t research paradigms be aligned accordingly?

When reversals of human phenotypes aren’t researched, problems may compound by being transmitted to the next generations.

http://www.sciencedirect.com/science/article/pii/S014976341630714X “Transgenerational effects of early environmental insults on aging and disease incidence” (not freely available)

How one person’s paradigms regarding stress and epigenetics impedes relevant research

This 2017 review laid out the tired, old, restrictive guidelines by which current US research on the epigenetic effects of stress is funded. The reviewer rehashed paradigms circumscribed by his authoritative position in guiding funding, and called for more government funding to support and extend his reach.

The reviewer won’t change his beliefs regarding individual differences and allostatic load pictured above since he helped to start those memes. US researchers with study hypotheses that would develop evidence beyond such memes may have difficulties finding funding except outside of his sphere of influence.


Here’s one example of the reviewer’s restrictive views taken from the Conclusion section:

Adverse experiences and environments cause problems over the life course in which there is no such thing as “reversibility” (i.e., “rolling the clock back”) but rather a change in trajectory [10] in keeping with the original definition of epigenetics [132] as the emergence of characteristics not previously evident or even predictable from an earlier developmental stage. By the same token, we mean “redirection” instead of “reversibility”—in that changes in the social and physical environment on both a societal and a personal level can alter a negative trajectory in a more positive direction.”

What would happen if US researchers proposed tests of his “there is no such thing as reversibility” axiom? To secure funding, the prospective studies’ experiments would be steered toward altering “a negative trajectory in a more positive direction” instead.

An example of this influence may be found in the press release of Familiar stress opens up an epigenetic window of neural plasticity where the lead researcher stated a goal of:

“Not to ‘roll back the clock’ but rather to change the trajectory of such brain plasticity toward more positive directions.”

I found nothing in citation [10] (of which the reviewer is a coauthor) where the rodent study researchers even attempted to directly reverse the epigenetic changes! The researchers under his guidance simply asserted:

“A history of stress exposure can permanently alter gene expression patterns in the hippocampus and the behavioral response to a novel stressor”

without making any therapeutic efforts to test the permanence assumption!

Never mind that researchers outside the reviewer’s sphere of influence have done exactly that, reverse both gene expression patterns and behavioral responses!!

In any event, citation [10] didn’t support an “there is no such thing as reversibility” axiom.

The reviewer also implied that humans respond just like lab rats and can be treated as such. Notice that the above graphic conflated rodent and human behaviors. Further examples of this inappropriate rodent / human merger of behaviors are in the Conclusion section.


What may be a more promising research approach to human treatments of the epigenetic effects of stress? As pointed out in The current paradigm of child abuse limits pre-childhood causal research:

“If the current paradigm encouraged research into treatment of causes, there would probably already be plenty of evidence to demonstrate that directly reducing the source of the damage would also reverse damaging effects. There would have been enough studies done so that the generalized question of reversibility wouldn’t be asked.

Aren’t people interested in human treatments of originating causes so that their various symptoms don’t keep bubbling up? Why wouldn’t research paradigms be aligned accordingly?”

http://journals.sagepub.com/doi/full/10.1177/2470547017692328 “Neurobiological and Systemic Effects of Chronic Stress”

The current paradigm of child abuse limits pre-childhood causal research

As an adult, what would be your primary concern if you suspected that your early life had something to do with current problems? Would you be interested in effective treatments for causes of your symptoms?

Such information wasn’t available in this 2016 Miami review of the effects of child abuse. The review laid out the current paradigm mentioned in Grokking an Adverse Childhood Experiences (ACE) score, one that limits research into pre-childhood causes for later-life symptoms.

The review’s goal was to describe:

“How numerous clinical and basic studies have contributed to establish the now widely accepted idea that adverse early life experiences can elicit profound effects on the development and function of the nervous system.”

The hidden assumptions of almost all of the cited references were that these distant causes could no longer be addressed. Aren’t such assumptions testable today?

As an example, the Discussion section posed the top nine “most pressing unanswered questions related to the neurobiological effects of early life trauma.” In line with the current paradigm, the reviewer assigned “Are the biological consequences of ELS [early life stress] reversible?” into the sixth position.

If the current paradigm encouraged research into treatment of causes, there would probably already be plenty of evidence to demonstrate that directly reducing the source of damage would also reverse damaging effects. There would have been enough studies done so that the generalized question of reversibility wouldn’t be asked.

Aren’t people interested in treatments of originating causes so that their various symptoms don’t keep bubbling up? Why wouldn’t research paradigms be aligned accordingly?


The review also demonstrated how the current paradigm of child abuse misrepresented items like telomere length and oxytocin. Researchers on the bandwagon tend to forget about the principle Einstein expressed as:

“No amount of experimentation can ever prove me right; a single experiment can prove me wrong.”

That single experiment for telomere length arrived in 2016 with Using an epigenetic clock to distinguish cellular aging from senescence. The review’s seven citations for telomere length that all had findings “associated with” or “linked to” child abuse should now be viewed in a different light.

The same light shone on oxytocin with Testing the null hypothesis of oxytocin’s effects in humans and Oxytocin research null findings come out of the file drawer. See their references, and decide for yourself whether or not:

“Claimed research findings may often be simply accurate measures of the prevailing bias.”

http://www.cell.com/neuron/fulltext/S0896-6273%2816%2900020-9 “Paradise Lost: The Neurobiological and Clinical Consequences of Child Abuse and Neglect”


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What’s the underlying question for every brain study to answer?

Is the underlying question for every brain study to answer:

  • How do our brains internally represent the external world?

Is it:

  • How did we learn what we know?
  • How do we forget or disregard what we’ve learned?
  • What keeps us from acquiring and learning newer or better information?

How about:

  • What affects how we pay attention to our environments?
  • How do our various biochemical states affect our perceptions, learning, experiences, and behavior?
  • How do these factors in turn affect our biology?

Or maybe:

  • Why do we do what we do?
  • How is our behavior affected by our experiences?
  • How did we become attracted and motivated toward what we like?
  • How do we develop expectations?
  • Why do we avoid certain situations?

Not to lose sight of:

  • How do the contexts affect all of the above?
  • What happens over time to affect all of the above?

This 2015 UCLA paper reviewed the above questions from the perspective of Pavlovian conditioning:

“The common definition of Pavlovian conditioning, that via repeated pairings of a neutral stimulus with a stimulus that elicits a reflex the neutral stimulus acquires the ability to elicit that the reflex, is neither accurate nor reflective of the richness of Pavlovian conditioning. Rather, Pavlovian conditioning is the way we learn about dependent relationships between stimuli.

Pavlovian conditioning is one of the few areas in biology in which there is direct experimental evidence of biological fitness.”


The most important question unanswered by the review was:

  • How can its information be used to help humans?

How can Pavlovian conditioning answer: What can a human do about the thoughts, feelings, behavior, epigenetic effects – the person – the phenotype – that they’ve been shaped into?

One example of the unanswered question: the review pointed out in a section about fear extinction that this process doesn’t involve unlearning. Fear extinction instead inhibits the symptoms of fear response. The fear memory is still intact, awaiting some other context to be reactivated and expressed.

How can this information be used to help humans?

  • Is inhibiting the symptoms and leaving the fear memory in place costless with humans?
  • Or does this practice have both potential and realized adverse effects?
  • Where’s the human research on methods that may directly address a painful emotional memory?

One relevant hypothesis of Dr. Arthur Janov’s Primal Therapy is that a person continues to be their conditioned self until they address the sources of their pain. A corollary is that efforts to relieve symptoms seldom address causes.

How could it be otherwise? A problem isn’t cured by ameliorating its effects.

http://cshperspectives.cshlp.org/content/8/1/a021717.full “The Origins and Organization of Vertebrate Pavlovian Conditioning”

Use it or lose it: the interplay of new brain cells, age, and activity

This 2015 German review was of aging and activity in the context of adult neurogenesis:

“Adult neurogenesis might be of profound functional significance because it occurs at a strategic bottleneck location in the hippocampus.


Age-dependent changes essentially reflect a unidirectional development in that everything builds on what has occurred before. In this sense, aging can also be seen as continued or lifelong development. This idea has limitations but is instructive with regard to adult neurogenesis, because adult neurogenesis is neuronal development under the conditions of the adult brain.

The age-related alterations of adult neurogenesis themselves have quantitative and qualitative components. So far, most research has focused on the quantitative aspects. But there can be little doubt that qualitative changes do not simply follow quantitative changes (e.g., in cell or synapse numbers), but emerge on a systems level and above when an organism ages. With respect to adult neurogenesis, only one multilevel experiment including morphology and behavior has been conducted, and, even in that study, only three time points were investigated.

In old age, adult neurogenesis occurs at only a small fraction of the level in early adulthood. The decline does not seem to be ‘regulated’ but rather the by-product of many age-related changes of other sorts.


From a behavioral level down to a synaptic level, activity increases adult neurogenesis. This regulation does not seem to occur in an all-or-nothing fashion but rather influences different stages of neuronal development differently. Both cell proliferation and survival are influenced by or even depend on activity.

The effects of exercise and environmental enrichment are additive, which indicates that increasing the potential for neurogenesis is sufficient to increase the actual use of the recruitable cells in the case of cognitive stimulation. Physical activity would not by itself provide specific hippocampus-relevant stimuli that induce net neurogenesis but be associated with a greater chance to encounter specific relevant stimuli.


Adult hippocampal neurogenesis might contribute to a structural or neural reserve that if appropriately trained early in life might provide a compensatory buffer of brain plasticity in the face of increasing neurodegeneration or nonpathological age-related functional losses. There is still only limited information on the activity-dependent parameters that help to prevent the age-dependent decrease in adult neurogenesis and maintain cellular plasticity.

The big question is what the functional contribution of so few new neurons over so long periods can be. Any comprehensive concept has to bring together the acute functional contributions of newly generated, highly plastic neurons and the more-or-less lasting changes they introduce to the network.”

I’ve quoted quite a lot, but there are more details that await your reading. A few items from the study referenced in the first paragraph above:

“The hippocampus represents a bottleneck in processing..adult hippocampal neurogenesis occurs at exactly the narrowest spot.

We have derived the theory that the function of adult hippocampal neurogenesis is to enable the brain to accommodate continued bouts of novelty..a mechanism for preparing the hippocampus for processing greater levels of complexity.”


The role of the hippocampus in emotion was ignored as it so often is. The way to address many of the gaps mentioned by the author may be to Advance science by including emotion in research.

For example, from the author’s The mystery of humans’ evolved capability for adults to grow new brain cells:

“Adult neurogenesis is already effective early in life, actually very well before true adulthood, and is at very high levels when sexual maturity has been reached. Behavioral advantages associated with adult neurogenesis must be relevant during the reproductive period.”

When human studies are designed to research how “behavioral advantages associated with adult neurogenesis must be relevant” what purpose does it serve to exclude emotional content?

http://cshperspectives.cshlp.org/content/7/11/a018929.full “Activity Dependency and Aging in the Regulation of Adult Neurogenesis”

Are hormone ratios useful in explaining health? Behavior? Neurobiology? Anything?

This 2015 Zurich human review addressed:

“A remarkable lack of discussion on the meaning and interpretation of frequently used hormone ratios.

The interpretation of hormone ratios is complicated and in many cases not sufficiently supported from a theoretical point of view.

Based on the assumption that the balance between two interdependent hormones determines their eventual effects on brain and other tissues, this index has been commonly interpreted as an indicator of the balance between two endocrine systems.

The ratio is typically calculated by simply dividing the raw value of one hormone by the raw value of a second hormone. However, endocrine parameters may fluctuate considerably within individuals across short periods of time on the basis of circadian rhythms or contextual factors. Nevertheless, the ratio method has so far only rarely been applied in the context of repeated endocrine assessments.”

The researchers made a non-exhaustive list of three dozen studies that used hormone ratios among cortisol, dehydroepiandrosterone sulfate (DHEA-S), estradiol, progesterone, testosterone, triiodothyronine (T3), thyroxine (T4), etc., to explain various outcome measures such as:

  • “Health status
  • Aggressive behavior
  • Psychopathy
  • Marital violence
  • fMRI response to angry and happy faces
  • Early life adversity
  • Depression
  • Chronic stress
  • Alexithymia”

Their 2015 study on “endocrine correlates of pro-environmental behavior” was used as an illustrative example. It had 229 male subjects between ages 19 and 77. Salivary cortisol (C) and testosterone (T) was sampled with these results:

“T/C and C/T ratios produce different means, standard deviations and distributional properties which significantly deviate from normality.

Height is not significantly associated with either T/C or C/T. In fact, looking at the original variables, C correlates positively with height while T shows no association.

When we include age as a covariate (assuming that it is associated with both height and hormone status) the partial correlation between T/C and height then is significant while the association between C/T and height is non-significant, even though both ratios are based on the exact same data.

Looking at the negative association between age and T/C the observed age-related ratio decline is mainly due to the fact that the T value in the numerator decreases with age while the C value in the denominator remains relatively constant. In this case, the analysis of the individual variables therefore offers more information and a more accurate picture of the underlying relationships.


A few previous studies have standardized the two underlying hormone distributions before calculating the ratio in order to account for the fact that two hormones often exhibit very different means and standard deviations. Standardization leads to values that express each subject’s hormone concentration relative to the sample mean.

A ratio calculated on the basis of such standardized hormones takes on a different meaning. In particular, the ratio no longer merely represents the proportion of the two hormones within the individual but also incorporates how high the two hormone concentrations are with respect to the sample distributions.”


Practices to improve the use and interpretation of hormone measurements included:

“Regression techniques employed on the original variables constitute a better suited alternative devoid of the problems associated with the ratio method. Moderation analysis, in particular, is a useful approach, which often provides more detailed insight into the relationships of interest.

Ratios should either be analyzed with non-parametric techniques, or be log-transformed before parametric statistical methods are applied.”

Set points and variations in an individual’s hormone balances are usually effects of underlying causes. Researchers will hopefully pay more attention to effectively dealing with ultimate causes as the preferred methods of managing an individual’s health, behavioral, and neurobiological effects.

http://www.psyneuen-journal.com/article/S0306-4530%2815%2900953-1/fulltext “How to use and interpret hormone ratios”

A problematic study of testosterone’s influence on behavior and brain measurements

This 2015 US/Canadian human study of people ages 6 to 22 years found:

“Testosterone-specific associations between amygdala volume and key prefrontal areas involved in emotional regulation and impulse control:

  1. Testosterone-specific modulation of the covariance between the amygdala and medial prefrontal cortex (mPFC);
  2. A significant relationship between amygdala-mPFC covariance and levels of aggression; and
  3. Mediation effects of amygdala-mPFC covariance on the relationship between testosterone and aggression.

These effects were independent of sex, age, pubertal stage, estradiol levels and anxious-depressed symptoms.

For the great majority of individuals in this sample, higher thickness of the mPFC was associated with lower aggression levels at a given amygdala volume. This effect diminished greatly and disappeared at more extreme amygdala values.”

The study provided noncausal associations among the effects (behavioral, hormonal, and brain measurements).


From the Limitations section:

“No umbilical cord or amniotic measurements were available in this study and we therefore cannot control for testosterone levels in utero, a period during which significant testosterone-related changes in brain structure are thought to occur.”

There’s evidence that too much testosterone for a female fetus and too little testosterone for a male fetus both have lifelong adverse effects. The researchers dismissed this etiologic line of inquiry with a “supporting the notion” referral to noncausal studies.


The researchers were keen to establish:

“A very specific, aggression-related structural brain phenotype.”

This putative phenotype hinged on:

  • Older subjects’ behavioral self-reports, and
  • Parental assessments of younger subjects’ behavior

exhibited during the previous six months, and within six months of their fMRI scan.

These self-reports and interested-party observations were the entire bases for the “aggressive behavior” and “anxious–depressed” associations! The researchers disingenuously provided multiple references and models for the reliability of these assessments.


Experimental behavioral measurements – such as those done to measure performance in decision studies – may have been more accurate and informative than what the older subjects chose to self-report about their own behavior over the previous six months.

People of all ages have an imperative to NOT be completely honest about their own behavior. One motivation for this condition is that some of our historical realities are too painful to enter our conscious awareness and inform us about our own behavior. As a result, our feelings, thoughts, and behavior are sometimes driven by our histories without us being aware of it.

For example, would a teenager/young adult subject self-report an impulsive act, even if they didn’t fully understand why they acted that way? Maybe they would if the act could be viewed as prosocial, but what if it was antisocial?

What are the chances that the lives of these teenager/young adult subjects were NOT filled with impulsive actions during the six months before their fMRI scans? Could complete and accurate self-reports of such behaviors be expected?

Experimental behavioral measurements may have also been more accurate and informative than second-hand, interested-party observations of the younger subjects. Could a parent who provided half of the genes and who was responsible for many of their child’s epigenetic changes make anything other than subjective observations of their handiwork’s behavior?


Epigenetic studies have shown that adaptations to environments are among the long-lasting causes for effects that include behavior, hormones, and brain measurements. Why, in 2015, did researchers spend public funds developing what they knew or should have known would be noncausal associations, while not investigating possible causes for these effects?

Why weren’t the researchers interested enough to gather and assess etiologic genetic and epigenetic evidence? Was it that difficult to get blood samples at the same time the subjects gave saliva samples, and perform selected genetic and DNA methylation analyses?

What did the study contribute towards advancing science? Who did the study really help?

My judgment: less than nothing; and nobody. The researchers only wasted public funds advancing a meme, giving it an imprimatur of science.

http://www.psyneuen-journal.com/article/S0306-4530%2815%2900924-5/fulltext “A testosterone-related structural brain phenotype predicts aggressive behavior from childhood to adulthood”

Fat made rats fat with dysfunctional brains

This 2015 New York rodent study found:

“Early stage [diet-induced] obesity, before the onset of diabetes or metabolic syndrome, produced deficits on cognitive tasks that require the prefrontal cortex.

These results strongly suggest that obesity must be considered as a contributing factor to brain dysfunction.”

The difference in the diets of the adult male subjects was that the control group ate 10% fat (20% protein, 70% carbohydrates) whereas the obese group ate 45% fat (20% protein, 35% carbohydrates). Significant changes in body weight were present after the first two weeks on the diets, but testing didn’t begin until after eight weeks.


I thought the study design prematurely terminated the experiments. The study didn’t justify the ultimate purpose of conducting rodent experiments, which is to find possible human applicability.

One study design possibility would have been to continue through old age to find how the conditions progressed. Another possibility would have been to reverse the high-fat diet to find whether the conditions reversed.

http://www.pnas.org/content/112/51/15731.full “Obesity diminishes synaptic markers, alters microglial morphology, and impairs cognitive function”

Fetal exposure to sex hormones and female anxiety

This 2015 Swedish rodent study found:

“Women with polycystic ovary syndrome (PCOS) display high circulating androgen levels that may affect the fetus and increase the risk of mood disorders in offspring.

Although clinical data are inconsistent, there are indications that androgens play a crucial role in behavior and mood regulation in females.

Studies on the link between testosterone and anxiety behavior in males have generated inconsistent results.

Higher circulating testosterone has previously been reported in female rat PNA [prenatal androgen] offspring. This discrepancy may be a result of the higher doses of maternal testosterone (5 mg) used in the previous study compared with the present study (0.5 mg).

Although the anxiety-like behavior observed in the female PNA offspring in the present study cannot be directly explained by high circulating androgens, the reduced AR [androgen receptor] expression in the amygdala suggests a compensatory response to the high prenatal testosterone exposure, a result implicating the amygdala as the CNS site underlying the changes in anxiety in the PNA offspring. This idea is further strengthened by our experiment showing that subchronic testosterone exposure into amygdala is sufficient to produce anxiety-like behavior in adult females.

Maternal testosterone exposure causes anxiety-like behavior in female, and to a lesser extent male offspring, an effect that seems to occur during fetal life and to be mediated via AR in the amygdala, together with changes in ER [estrogen receptor] and in the serotonergic and GABAergic pathways in the amygdala and hippocampus of female PNA rats.”

The news coverage – too much testosterone caused anxiety-like symptoms in females whether they are adults or fetuses – was NOT what the study found. The headlines disregarded its caveat:

“The anxiety-like behavior observed in the female PNA offspring in the present study cannot be directly explained by high circulating androgens.”

I look forward to research on floor levels of testosterone, below which there are also adverse effects on females. There is such evidence, but would it play well with popular memes?

See Sex hormone exposure to the developing female fetus causes infertility in adulthood for another study that used the PCOS phenotype.

http://www.pnas.org/content/112/46/14348.full “Maternal testosterone exposure increases anxiety-like behavior and impacts the limbic system in the offspring”

Who’s responsible for your physical and emotional health?

This 2015 Houston human study measured 575 metabolites in 72 biochemical pathways. The researchers used “nontargeted metabolomics” with next-generation gene sequencing to:

“Take account of human individuality in genes, environment, and lifestyle for early disease diagnosis and individualized therapy.”

The 80 subjects were 45 men and 35 women, average age of 54, in “normal health with complete medical records and three-generation pedigrees.” The subjects all had college degrees, and were members or spouses of members of an upper-level socioeconomic organization.

The study’s range of 575 metabolites certainly cast a shadow over studies such as Running a marathon, cortisol, depression, causes, effects, and agendas that singled out 1 metabolite and tortured its data until it confessed a relationship that supported the preferred agenda.


Limitations of this study that weren’t mentioned by the researchers included:

  1. There were no specific target levels for each metabolite, which could lead to a misinterpretation that a “healthy” blood plasma level of a metabolite would always be the norm of the 80 subjects. This interpretation of each metabolite’s ideal level could be reinforced by the study calculating z-scores and P values of each individual’s measurement’s position within the cohort. The researchers stated:

    “The identification of abnormal metabolic signatures was restricted by the relatively small number of subjects in the cohort.”

    but that limitation wasn’t the flip side of omitted optimal levels.

  2. The metabolite measurements were mainly a one-time event although a series of measurements may have been more appropriate. Many of these metabolite levels vary with the time of day, what each individual had recently eaten, what each individual’s recent stress levels were, etc. This limitation may have been one of the sources for what the researchers noted:

    “Statistical analysis revealed a considerable range of variation and potential metabolic abnormalities across the individuals in this cohort.”

  3. There was no assessment of the relative contributions of epigenetic and genetic factors when discussing possible genetic impacts.

Regarding 1. above:

  • It may be interesting to compare an individual to their peers and to other sources of information. However, when it comes time for “individualized therapy” because of a metabolic measurement that’s an outlier compared to these other sources, an individual’s history also matters.
  • Each individual’s history could be used as a guide for optimal levels of some metabolites. For example, an optimal goal for “individualized therapy” for low testosterone levels of each of the 54-year old male subjects could be each individual’s previous higher levels of three decades earlier. It wouldn’t make sense for a 54-year old male to start testosterone therapy with a goal of raising his low levels to the non-therapeutic, low-level norm of other 54-year old males.

Regarding 2. above:

Regarding 3. above:

  • As an example of unconsidered epigenetic factors, there was a discussion of acetaminophen metabolites because:

    “The identification of at-risk populations could improve therapeutic options for individual patients and prevent adverse clinical outcomes.”

    The researchers specifically compared and contrasted two subjects with the highest levels of acetaminophen metabolites, and concluded:

    “These observations may suggest that volunteer 3976 was sensitive to acetaminophen-induced liver injury, whereas volunteer 3958 could tolerate acetaminophen well. This difference may relate to their cellular capability to maintain GSH [reduced glutathione] levels in response to acetaminophen. We searched for a genetic basis of this variation in acetaminophen degradation/toxic metabolism without success.”

  • The researchers shouldn’t have left the discussion hanging at this point. There’s no reason in 2015 for researchers to not investigate the contribution of epigenetic factors to:

    “Take account of human individuality in genes, environment, and lifestyle.”


I was put off by the researchers statement:

“The volunteer’s cardiologist was informed of this observation to monitor possible drug interaction or toxicity.”

It appeared that the researchers bypassed one subject and informed the subject’s doctor directly when the subject was doing something the researchers considered detrimental to the subject’s health. I don’t know if the subject gave prior consent to be bypassed, though, because I didn’t see either study’s consent terms in the below linked material.


A few concluding questions:

  • If it’s alright for personal health information to be transmitted without the consent of highly-educated, upper-level socioeconomic subjects, what can the rest of the population expect?
  • Is “individualized therapy” best done through individual choices, or by forcing an individual to conform to expert opinion?
  • Who is responsible for an individual’s physical and emotional health?

http://www.pnas.org/content/112/35/E4901.full “Plasma metabolomic profiles enhance precision medicine for volunteers of normal health”

http://www.pnas.org/content/110/42/16957.full “Personalized genomic disease risk of volunteers” (2013 original study with the same subjects)

Stress in early life can alter physiology and behavior across the entire lifespan

I’ll quote a few sections of this 2014 summary of 111 studies concerning stress, including the authors’ research:

“The brain is the central organ of stress and adaptation to stressors because:

  • It not only perceives what is threatening or potentially threatening and initiates behavioral and physiological responses to those challenges,
  • But also is a target of the stressful experiences and the hormones and other mediators of the stress response.

The stress history of parents is a significant factor in the resilience of their offspring.

Environmental stress transduces its effects into lasting changes on physiology and behavior, which can vary even among genetically identical individuals.

Stress in early life can alter physiology and behavior across the entire lifespan.

Structural stress memory is even more apparent with regard to gene expression in stress-sensitive brain regions like the hippocampus.

Individual history is important and that there is a memory of stress history retained by neurons at the cellular level in regions like the hippocampus.

Stress has a number of known effects on epigenetic marks in the brain, producing alterations in DNA methylation and histone modifications in most of the stress-sensitive brain regions examined, including the hippocampus, amygdala, and prefrontal cortex.”


It seemed to be taboo to note that most of – and the largest of – detrimental effects of stress occurred during womb-life in the mother’s environment. The authors instead opted for a politically correct “the stress history of parents” phrase.

Referenced studies had findings relevant to the earliest periods of life, including Figure 1:

interactions

“Those organs that show the highest levels of retrotransposon [a repeat element (mobile DNA sequences often involved in mutations) type formed by copy-and-paste mechanisms] activity, such as the brain and placenta, also seem to be both steroidogenic and steroid-sensitive.”

However, Figure 1 was given a beneficial context, and other studies’ findings weren’t mentioned in their contexts of detrimental effects on fetuses of mothers who were stressed while pregnant.

http://www.pnas.org/content/112/22/6828.full “Stress and the dynamic genome: Steroids, epigenetics, and the transposome”

How to make a child less capable even before they are born: stress the pregnant mother-to-be

This 2014 rodent study showed how to make a less-capable pup by stressing the mother early in gestation. The study centered on a placental enzyme (OGT) that translates a mother’s stress into neuroprogramming of her developing fetus.

One finding was that this enzyme was less plentiful when the fetus was male compared with female.

Another finding was that the enzyme was less plentiful when the mother was stressed early in gestation, compared with unstressed mothers.

Informed by the first two findings, the researchers studied the placentae of male pups where the mother was stressed early in gestation. They found that these placentae had lower levels of an enzyme (Hsd17b3) that converts the precursor androstenedione into testosterone.

The resultant finding was that the male pups of stressed mothers had lower levels of testosterone than the control group of male pups.

A fourth finding was that offspring of both sexes born with a placenta where the OGT enzyme was less plentiful had 10-20% less body weight, a condition that developed after weaning. The researchers attributed this finding to reduced mitochondrial function in the hypothalamus compared with normal mice.

http://www.pnas.org/content/111/26/9639.full “Targeted placental deletion of OGT recapitulates the prenatal stress phenotype including hypothalamic mitochondrial dysfunction”