Definitive benefits of breakfast omission or consumption are not supported by the best evidence-based research, & whether skipping breakfast per se is causally associated with cardiovascular outcomes remains unresolved

Association of breakfast skipping with cardiovascular outcomes and cardiometabolic risk factors: an updated review of clinical evidence. Heitor O. Santos et al. Critical Reviews in Food Science and Nutrition, Sep 16 2020. https://doi.org/10.1080/10408398.2020.1819768

Rolf Degen's take: https://twitter.com/DegenRolf/status/1306529109724598272

Abstract: “Eat breakfast like a king, lunch like a prince and dinner like a pauper” (Adelle Davis, 1904–1974) is a concept that appears to align with some contemporary evidence concerning the appropriate proportioning of daily meals. At the same time, with the popular and scientific dissemination of the concepts of intermittent fasting and time-restricted feeding, well-controlled clinical trials have emerged showing the safety or even possible benefits of skipping breakfast. In this comprehensive literature review, we discuss recent evidence regarding breakfast intake, cardiovascular outcomes and cardiovascular risk markers. Overall, breakfast omission appears to be associated with a higher risk for atherosclerotic and adverse cardiovascular outcomes. However, caution should be employed when deciphering these data as many complex, unmeasured confounders may have contributed. Unfortunately, long-term randomized, clinical trials with detailed dietary control that have assessed clinical outcomes are sparse. Notwithstanding the observational findings, current trials conducted so far—albeit apparently smaller number—have shown that breakfast addition in subjects who do not habitually consume this meal may increase body weight, particularly fat mass, through caloric excess, whereas skipping breakfast may be a feasible strategy for some people aiming for calorie restriction. To date, definitive benefits of breakfast omission or consumption are not supported by the best evidence-based research, and the question of whether skipping breakfast per se is causally associated with cardiovascular outcomes remains unresolved.

Keywords: Cardiovascular disease, clinical nutrition, intermittent fasting, skipping breakfast, time-restricted feeding

In this population-based cohort study of 2583 children with neuroimaging data, smaller hippocampal volumes were found in preadolescents exposed to prenatal maternal-reported poor family functioning

Association of Poor Family Functioning From Pregnancy Onward With Preadolescent Behavior and Subcortical Brain Development. Yllza Xerxa et al. JAMA Psychiatry, September 16, 2020. doi:10.1001/jamapsychiatry.2020.2862

Key Points
Question  To what extent is the persistent association of poor prenatal family functioning with preadolescent problem behavior mediated by subcortical brain development?

Findings  In this population-based cohort study of 2583 children with neuroimaging data, smaller hippocampal volumes were found in preadolescents exposed to prenatal maternal-reported poor family functioning. Smaller hippocampal volumes partially mediated the association of prenatal maternal-reported poor family functioning with preadolescent problem behavior.

Meaning  Subcortical brain characteristics found after more than 10 years of follow-up may help clinicians understand why poor family functioning is associated with child neurodevelopment and well-being.

Abstract
Importance  The association of poor family functioning, a potent stressor, with child behavior is potentially long term and relevant for a person’s well-being later in life. Whether changes in brain development underlie the associations with preadolescent behavior and help identify periods of vulnerability is unclear.

Objective  To assess the associations of poor family functioning from pregnancy onward with cortical, white matter, and subcortical volumes, and to examine the extent to which, in particular, hippocampal volume mediates the association of prenatal parental environmental exposures with child problem behavior in preadolescence.

Design, Setting, and Participants  This population-based cohort study, conducted from April 2002 to January 2006, was embedded in Generation R, a multiethnic population-based cohort from fetal life onward. All pregnant women living in Rotterdam, the Netherlands, with an expected delivery date between April 2002 and January 2006 were invited to participate. Of the 8879 pregnant women enrolled during pregnancy, 1266 mothers with no partner data and 490 with missing family functioning data were excluded, as well as 1 sibling of 32 twin pairs. After excluding an additional 657 children with poor imaging data quality or incidental findings, the final sample consisted of 2583 mother-child pairs. Data analysis was performed from March 1, 2019, to June 28, 2019.

Exposures  Mother- and father-rated poor family functioning was repeatedly measured by the General Functioning subscale of the Family Assessment Device.

Main Outcomes and Measures  Our primary hypothesis, formulated after data collection but before analysis, was that poor prenatal family functioning would be associated with smaller hippocampal and amygdala volumes in late childhood. High-resolution structural neuroimaging data of children aged 10 years were collected with a single 3-T magnetic resonance imaging system. Child emotional and behavioral problems were assessed with the Child Behavior Checklist.

Results  Data were available for 2583 children (mean [SD] age, 10.1 [0.6] years; 1315 girls [50.9%]). Data for parents included 2583 mothers (mean [SD] age, 31.1 [4.7] years; 1617 Dutch race/ethnicity [62.6%]) and 1788 fathers (mean [SD] age, 33.5 [5.3] years; 1239 Dutch race/ethnicity [69.3%]). Children exposed to prenatal maternal-reported poor family functioning had smaller hippocampal (B = −0.08; 95% CI, −0.13 to −0.02) and occipital lobe (B = −0.70; 95% CI, −1.19 to −0.21) volumes in preadolescence. There was no evidence for an association of exposure to poor family functioning at mid- or late childhood with brain morphology. Hippocampal volumes partially mediated the association of prenatal maternal-reported poor family functioning with preadolescent problem behavior (B = 0.08; 95% CI, 0.03-0.13), even after adjusting for prior child problems at age 1.5 years. Analyses of combined maternal and paternal family functioning ratings showed similar results, but associations were largely driven by maternal family functioning reports.

Conclusions and Relevance  In this population-based cohort study, prenatal maternal-reported poor family functioning was associated with a smaller hippocampus in preadolescents. This difference in brain structure may underlie behavioral problems and is a possible neurodevelopmental manifestation of the long-term consequences of poor family functioning for the child.

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Discussion

This cohort study of children from fetal life onward suggests that poor maternal-reported prenatal family functioning is associated with brain development in late childhood. In particular, we observed smaller hippocampal volumes in children exposed to poor family functioning occurring prenatally but not in mid- or late childhood. The association remained when we accounted for parental psychopathology and harsh parenting, indicating a unique association of poor prenatal family functioning with differences in preadolescent brain development. The contribution of prenatal maternal-reported poor family functioning to preadolescent problem behavior was partially mediated by hippocampal volumes. Interestingly, prenatal maternal-reported poor family functioning was associated with smaller occipital lobe volumes. Associations between poor family functioning and brain outcomes did not differ by child sex.

The vulnerability of the hippocampus to prenatal family functioning is consistent with previous studies reporting that the hippocampus matures rapidly and is functional very early in childhood.^41,42 That the association between poor family functioning and hippocampal volumes was observed only from prenatal maternal-reported family functioning and not from mid- or late-childhood family functioning may reflect a sensitive period, which occurs early in life.⁴³ Other research supports this inference. For example, higher levels of early-life maternal support have been linked to increased volume of the hippocampus.^44,45 Our key finding, namely the interaction of poor family functioning with child age, suggests that pregnancy is a vulnerable period when development in response to parental care disruptions is maximally dynamic.⁴⁶

In contrast to our hypothesis, we were not able to demonstrate an association between poor family functioning and amygdala volumes. The lack of a discernible sensitive period to family functioning for amygdala development is consistent with previous studies of children exposed to adversity, which have found no difference in amygdala volume in adults.⁴⁷

The present findings provide evidence for a smaller occipital lobe in children exposed to prenatal maternal-reported poor family functioning. This observation, which was not expected a priori, should be interpreted with caution until it is replicated. However, the face-processing systems relating to occipital regions, in particular the lateral occipital lobe, were found to be particularly vulnerable to early-life adversities.^48-50

Furthermore, we found that the association between prenatal maternal-reported poor family functioning and preadolescent problem behavior was partially mediated by hippocampal volumes. This may suggest that brain morphologic changes precede or may even contribute to behavioral changes. Our results are consistent with the extant literature, showing that smaller hippocampal volumes partially mediated the contribution of early-life stress to higher levels of behavioral problems.²¹ However, it is likely that the associations in the mediation model are more complex, and they may well be bidirectional. A sample with multiple repeated measures of imaging data starting early in childhood would be necessary to test the directionality between behavior and brain development. Indeed, a twin study in veterans with PTSD showed that a smaller hippocampus may reflect a preexisting vulnerability to stress and thus reverse causality.²⁰ Alternatively, the difference in hippocampal volume could be explained by genetic variation. Recently, a genome-wide association meta-analysis identified a few genetic loci associated with hippocampal volume,⁵¹ which could be (indirectly) associated with poor family functioning.

In addition, associations between paternal-reported family functioning and brain structural measures did not remain after adjustment for sociodemographic factors and paternal psychopathology. Although prenatal parental family functioning factors reflect a common variance across mother- and father-reported family functioning, their association with brain structural measures was largely driven by the maternal report. Thus, the clear association found using maternal-reported functioning during pregnancy suggests that direct maternal physiological changes may underlie the findings. This is consistent with the developmental origins hypothesis that the prenatal or early postnatal environment can be associated with negative health outcomes later in life. Maternal psychological distress may lead to a suboptimal intrauterine environment with long-term consequences for the growth and health of the child.^52-54 Intrauterine stress exposure may affect child development via dysregulation of the hypothalamic-pituitary-adrenal axis, but it may also affect brain development through inflammatory responses and changes in the balance of the autonomic nervous system.⁵⁵ Another potential mechanism is dietary behavior and poor nutrition by which a variation in maternal nutrition (either a surplus or paucity of maternal nutrition) plays multiple roles in the health outcomes of children.⁵⁶ However, postnatal experiences cannot be ruled out as a mechanism underlying our findings, because the prenatal period could be a marker of exposures in the early postnatal period, such as poor parenting.⁵⁷ Thus, children of parents with poor family functioning may be more likely to experience a less optimal environment, which underlies the relation with brain developmental differences.

Parental psychopathology remains another important mechanism potentially underlying our observations. However, when we adjusted for parental psychopathology, we found that the association between poor prenatal family functioning and hippocampal volumes was, if anything, stronger. Thus, our results suggest that poor family functioning and parental psychopathology are closely associated and may predispose each other,¹³ but higher levels of parental psychopathology did not account for the association of poor family functioning with hippocampal volume.

Limitations and Strengths

The current study has several limitations. First, this study has a population-based design, but the relative homogeneity of the population limits its generalizability. Second, we found an association between poor prenatal family functioning and preadolescent brain morphology among children aged 10 years. Although we assessed prenatal family functioning, we cannot establish whether these associations result from strictly prenatal exposures or whether our measure indexes childhood exposure during the period up to age 6 years when parents were reassessed. Third, because poor family functioning was associated with brain findings in children aged 10 years, it is possible that the associations of family functioning reported prenatally had their effects in utero. However, because no scans were obtained before age 10, this cannot be determined. Furthermore, we were unable to examine whether the parental hippocampus is a marker of vulnerability that increases the likelihood of poor family adjustment and whether this propensity is transmitted genetically to the children. Strengths of the present study are the large number of participants and broad spectrum of measured covariates, which enabled us to adjust for multiple confounders. Because of our longitudinal design, we were able to look at possible sensitive periods by leveraging baseline and repeated assessments of poor family functioning reported by both mothers and fathers.

But it is no longer reasonable, contra some predictions, to expect that advances in human genomics will reveal that the heritability of psychological phenotypes is entirely illusory

“Reports of My Death Were Greatly Exaggerated”: Behavior Genetics in the Postgenomic Era. K. Paige Harden. Annual Review of Psychology, Vol. 72, January 2021, online September 8, 2020. https://doi.org/10.1146/annurev-psych-052220-103822

Abstract: Behavior genetics studies how genetic differences among people contribute to differences in their psychology and behavior. Here, I describe how the conclusions and methods of behavior genetics have evolved in the postgenomic era in which the human genome can be directly measured. First, I revisit the first law of behavioral genetics stating that everything is heritable, and I describe results from large-scale meta-analyses of twin data and new methods for estimating heritability using measured DNA. Second, I describe new methods in statistical genetics, including genome-wide association studies and polygenic score analyses. Third, I describe the next generation of work on gene environment interaction, with a particular focus on how genetic influences vary across sociopolitical contexts and exogenous environments. Genomic technology has ushered in a golden age of new tools to address enduring questions about how genes and environments combine to create unique human lives.

Keywords: behavior genetics, twin studies, heritability, gene–environment interaction,
genome-wide association study, polygenic scores

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An early study using a DNA-based method estimated the heritability of height to be ∼80%,and it noted that this result was “consistent with results from independent twin and family studies but using an entirely separate source of information” (Visscher et al. 2006). However, although the results from DNA-based method of estimating heritability scale with the estimates from twin and family studies, the former are typically smaller (Young et al. 2019). This discrepancy between heritability as estimated from classical twin and family studies and heritability as accounted for by measured DNA was labeled the missing heritability problem (Manolio et al. 2009). Recent work has suggested that some of the missing heritability is actually “hiding” in rare variants that are not typically measured and in the heterogeneity of genetic effects across populations (Tropfet al. 2017, Wainschtein et al. 2019, Young 2019). Whether missing or hiding, the continued gap between DNA-based estimates of heritability and estimates from twin/family studies means that the latter might still be overestimating heritability due to faulty assumptions. But it is no longer reasonable, contra some predictions, to expect that advances in human genomics will reveal that the heritability of psychological phenotypes is entirely illusory.

[...]

In contrast to what is seen for educational attainment, most studies find a minimal effect of shared environmental factors on cognitive abilities, particularly when measured in adulthood. It has been suggested,however,that this near-zero main effect of the family-level environment masks the heterogeneity of the effects of the shared environment across the SES spectrum.An early paper by Turkheimer et al. (2003) analyzed data from a sample of twins with an unusual overrepresentation of children in poverty and found substantial effects of the shared environment on cognitive ability at age 7. Subsequent research on the genotype×SES interaction effect yielded mixed results, with several studies finding null effects or even effects in the opposite direction. However, a meta-analysis of this literature (Tucker-Drob & Bates 2016) found evidence of a significant interaction effect (albeit with a smaller effect size than estimated by Turkheimer and colleagues, an example of the winner’s curse), particularly in the United States.

The importance of the shared environment for cognitive ability has also been demonstrated using adoption studies. In particular, population-wide data from Sweden allowed researchers to estimate the impact of the family environment using a unique sample of male-male sibling pairs where one brother was adopted while the other brother was raised by his biological parents (Kendler et al.2015). The IQ score of the adopted brother was, on average, ∼4 points higher, an increase that varied with the education level of the adopting parents.

COVID-19: Openness, conscientiousness, agreeableness, and neuroticism all predicted higher rates of sheltering-in-place, whereas extraversion was negatively related to staying at home

Götz, Friedrich M., Andrés Gvirtz, adam galinsky, and Jon Jachimowicz. 2020. “How Personality and Policy Predict Pandemic Behavior: Understanding Sheltering-in-place in 55 Countries at the Onset of COVID-19.” PsyArXiv. September 10. doi:10.1037/amp0000740

Abstract: The spread of COVID-19 within any given country or community at the onset of the pandemic depended in part on the sheltering-in-place rate of its citizens. The pandemic led us to revisit one of psychology’s most fundamental and most basic questions in a high-stakes context: What determines human behavior? Adopting a Lewinian interactionist lens, we investigate the independent and joint effects of macro-level government policies and micro-level psychological factors—i.e., personality—on whether individuals sheltered-in-place. We analyzed data collected in late March and early April 2020 from 101,005 participants in 55 countries, a time period that coincided with the early and accelerating stage of the COVID-19 pandemic. This time period also contained substantial variation in the stringency of governmental policy towards sheltering-in-place, both between countries and within each country over time. Analyses revealed that personality and the stringency of governmental policies independently predicted sheltering-in-place rates. Policy stringency was positively related to sheltering-in-place. For the personality dimensions, openness, conscientiousness, agreeableness, and neuroticism all predicted higher rates of sheltering-in-place, whereas extraversion was negatively related to staying at home. In addition, two personality traits—openness to experience and neuroticism—interacted with governmental policy to predict whether individuals sheltered-in-place; openness and neuroticism each had weaker effects on sheltering-in-place as governmental policies became stricter. Theoretically, the findings demonstrate that individual differences predict behavior (i.e., sheltering-in-place) even when governments take strong action targeting that behavior. Practically, they suggest that even if governments lift their shelter-in-place restrictions, some individuals will shelter-in-place less than others.

Men have an advantage in concurrent multitasking, and that may be a result of the individual differences in cognitive abilities

Gender Differences in Multitasking Experience and Performance. Kelvin F. H. Lui, Ken H. M. Yip, Alan C.-N. Wong. Quarterly Journal of Experimental Psychology, September 16, 2020. https://doi.org/10.1177/1747021820960707

Rolf Degen's take: https://twitter.com/DegenRolf/status/1306478689375248385

Abstract: There is a widespread stereotype that women are better at multitasking. Previous studies examining gender difference in multitasking used either a concurrent or sequential multitasking paradigm and offered mixed results. The present study examined a possibility that men were better at concurrent multitasking while women were better at task switching. In addition, men and women were also compared in terms of multitasking experience, measured by a computer monitoring software, a self-reported Media Use Questionnaire, a lab task switching paradigm, and a self-reported Multitasking Prevalence Inventory. Results showed a smaller concurrent multitasking (dual-task) cost for men than women and no gender difference in sequential multitasking (task switching) cost. Men had more experience in multitasking involving video games while women were more experienced in multitasking involving music, instant messaging, and web surfing. The gender difference in dual-task performance, however, was not mediated by the gender differences in multitasking experience but completely explained by difference in the processing speed. The findings suggest that men have an advantage in concurrent multitasking, and that may be a result of the individual differences in cognitive abilities.

Keywords gender difference, multitasking, dual-task performance, task switching, experience

Check also Moderate amounts of media multitasking are associated with optimal task performance and minimal mind wandering. Myoungju Shin, Astrid Linke, Eva Kemps. Computers in Human. Behavior, Volume 111, October 2020, 106422. https://www.bipartisanalliance.com/2020/05/moderate-amounts-of-media-multitasking.html