The primary causes of individual differences in DNA methylation are environmental factors

This 2015 Canadian human study by McGill researchers found: “Differential methylation is primarily non-genetic in origin, with non-shared environment accounting for most of the variance. These non-genetic effects are mainly tissue-specific. The full scope of environmental variation remains underappreciated.” The researchers developed their findings using adipose and blood samples from monozygotic and dizygotic twins in … Continue reading The primary causes of individual differences in DNA methylation are environmental factors

If research treats “Preexisting individual differences” as a black box, how can it find causes for stress and depression?

This 2014 research studied both humans and rodents to provide further evidence on the physiology of defeat. The researchers demonstrated that with mice: “Bone marrow transplants of stem cells that produce leucocytes lacking IL-6 (the cytokine interleukin 6) or when injected with antibodies that block IL-6 prior to stress exposure, the development of social avoidance … Continue reading If research treats “Preexisting individual differences” as a black box, how can it find causes for stress and depression?

Group statistics don’t necessarily describe an individual

I’m curating this 2018 UC Berkeley/Drexel/Netherlands analysis of human studies via its press coverage. The authors: “Collaborated to analyze data on hundreds of adults – some mentally or physically sound, others suffering from various conditions such as depression, anxiety, or post-traumatic stress disorder. Participants had completed surveys about their mental health and had their heart … Continue reading Group statistics don’t necessarily describe an individual

Do our unique visual perceptions arise from brain structural differences?

This 2014 UK/German human study involved fMRI scans of the subjects inferior temporal cortex while viewing images: “Brain representational idiosyncrasies accessible to fMRI are expressed in an individual’s perceptual judgments. We found evidence for an individually unique representation predictive of perceptual idiosyncrasies in hIT [human inferior temporal cortex] (but not in early visual areas) and … Continue reading Do our unique visual perceptions arise from brain structural differences?

PTSD susceptibility?

This 2021 rodent study investigated post-traumatic stress disorder (PTSD) susceptibility: “PTSD is an incapacitating trauma-related disorder, with no reliable therapy. We show distinct DNA methylation profiles of PTSD susceptibility in the nucleus accumbens (NAc). Data analysis revealed overall hypomethylation of different genomic CpG sites in susceptible animals. Is it possible to treat PTSD by targeting … Continue reading PTSD susceptibility?

Dietary fibers and the aged microbiome

This 2021 rodent study investigated effects of four different types of dietary fiber on two different types of aged human microbiota: “Individual differences in gut microbiota may influence host metabolic responses to dietary fiber in humans. Dietary fibers are edible carbohydrates resistant to host digestive enzymes, and not broken down or absorbed in the small … Continue reading Dietary fibers and the aged microbiome

Eat broccoli sprouts daily, and manage weight

This 2018 human study found: “The objective of this study was to determine whether daily broccoli consumption alters absorption and metabolism of isothiocyanates derived from broccoli glucosinolates. We conducted a randomised cross-over human study (n = 18) balanced for BMI and glutathione S-transferase μ 1 (GSTM1) genotype in which subjects consumed a control diet with … Continue reading Eat broccoli sprouts daily, and manage weight

Part 2 of Switch on your Nrf2 signaling pathway

To follow up topics of Part 1‘s interview: 1. “We each have a unique microbial signature in the gut. Metabolites that you produce might not be the same ones that I produce. This makes clinical studies very difficult because you don’t have a level playing field.” This description of inter-individual variability could inform researchers’ investigations … Continue reading Part 2 of Switch on your Nrf2 signaling pathway

Does sulforaphane reach the colon?

This 2020 study subject was antimicrobial activity of sulforaphane: “This study explored the role that digestion and cooking practices play in bioactivity and bioavailability, especially the rarely considered dose delivered to the colon. A broccoli powder soup was prepared which contained 26.5 µmol of sulforaphane per 200 ml portion. Addition of 2% mustard seed powder … Continue reading Does sulforaphane reach the colon?

Week 28 of Changing to a youthful phenotype with broccoli sprouts

Did a little math to end this 28th week of eating a clinically relevant weight of microwaved broccoli sprouts every day: I changed the title of weekly updates after Week 7 as a result of A rejuvenation therapy and sulforaphane. Numbers used from its study: “Rats were injected four times on alternate days for 8 … Continue reading Week 28 of Changing to a youthful phenotype with broccoli sprouts

Unraveling oxytocin – is it nature’s medicine?

This 2020 review attempted to consolidate thousands of research papers on oxytocin: “Chemical properties of oxytocin make this molecule difficult to work with and to measure. Effects of oxytocin are context-dependent, sexually dimorphic, and altered by experience. Its relationship to a related hormone, vasopressin, have created challenges for its use as a therapeutic drug. Widely … Continue reading Unraveling oxytocin – is it nature’s medicine?

A cherry-picked DNA methylation study

This 2020 US/Sweden/Denmark human study measured twins during their old age: “We evaluate individual differences in DNA methylation at individual CpG sites across the methylome across 10 years in two Scandinavian samples of same‐sex aging twins. We test two competing hypotheses about the longitudinal stability and change in DNA methylation: The contribution of genetic influences … Continue reading A cherry-picked DNA methylation study

Do genes or maternal environments shape fetal brains?

This 2019 Singapore human study used Diffusion Tensor Imaging on 5-to-17-day old infants to find: “Our findings showed evidence for region-specific effects of genotype and GxE on individual differences in human fetal development of the hippocampus and amygdala. Gene x Environment models outcompeted models containing genotype or environment only, to best explain the majority of … Continue reading Do genes or maternal environments shape fetal brains?

Statistical inferences vs. biological realities

A 2019 UCLA study introduced a derivative of the epigenetic clock named GrimAge: “DNAm GrimAge, a linear combination of chronological age, sex, and DNAm-based surrogate biomarkers for seven plasma proteins and smoking pack-years, outperforms all other DNAm-based biomarkers, on a variety of health-related metrics. An age-adjusted version of DNAm GrimAge, which can be regarded as … Continue reading Statistical inferences vs. biological realities