People whose parents divorced during their childhood may be at a greater risk of stroke later in life, according to a new study published January 22, 2025 in the open-access journal PLOS One by Esme Fuller-Thomson of University of Toronto, Canada, and colleagues.
Each year, approximately 795 000 individuals in the U.S. have a stroke. Previous work has established many sociodemographic risk factors for stroke, as well as connections between adverse childhood events and stroke. In the new study, researchers looked specifically at the impact of childhood parental divorce among adults with no history of childhood abuse. They used data on 13 205 adults aged 65 and over from the 2022 Behavioral Risk Factor Surveillance System.
The study found that people who had experienced parental divorce before they were 18 years old had 1.61 times higher odds of having a stroke when compared to respondents who did not experience parental divorce (AOR=1.61, 95% CI=1.15-2.24). The association did not vary by sex, and remained even after controlling for known risk factors such as diabetes, depression, and small social support networks.
The current study was not designed to analyse the potential mechanism of this association, nor to prove causation. The conclusions may not be generalisable to younger generations, who have experienced overall higher rates of parental divorce. In addition, several potential confounding factors – including blood pressure, cholesterol, contraceptive use, age at parents’ divorce, and types of strokes – were not available in the data.
However, the authors say that their data supports an association between parental divorce during childhood and increased stroke risk, even in the absence of childhood abuse and other trauma.
Senior author Esme Fuller-Thomson adds: “It is extremely concerning that older adults who grew up in divorced families had 60% higher odds of stroke, even after excluding those who had been physically or sexually abused as children. The magnitude of the association between parental divorce and stroke was comparable to well-established risk factors for stroke such as male gender and having diabetes.”
The soft, gentle murmurs of a baby’s first expressions, like little whispers of joy and wonder to doting parents, are actually signs that the baby’s heart is working rhythmically in concert with developing speech.
Jeremy I. Borjon, University of Houston assistant professor of psychology, reports in Proceedings of the National Academy of Sciences that a baby’s first sweet sounds and early attempts at forming words are directly linked to the baby’s heart rate. The findings have implications for understanding language development and potential early indicators of speech and communication disorders.
For infants, producing recognisable speech is more than a cognitive process. It is a motor skill that requires them to learn to coordinate multiple muscles of varying function across their body. This coordination is directly linked to ongoing fluctuations in heart rate.
Borjon investigated whether these fluctuations in heart rate coincide with vocal production and word production in 24-month-old babies. He found that heart rate fluctuations align with the timing of vocalizations and are associated with their duration and the likelihood of producing recognisable speech.
“Heart rate naturally fluctuates in all mammals, steadily increasing then decreasing in a rhythmic pattern. It turns out infants were most likely to make a vocalisation when their heart rate fluctuation had reached a local peak (maximum) or local trough (minimum),” reports Borjon.
“Vocalisations produced at the peak were longer than expected by chance. Vocalisations produced just before the trough, while heart rate is decelerating, were more likely to be recognised as a word by naïve listener,” he said.
Borjon and team measured a total of 2708 vocalisations emitted by 34 infants between 18 and 27 months of age while the babies played with a caregiver. Infants in this age group typically don’t speak whole words yet, and only a small subset of the vocalisations could be reliably identified as words by naïve listeners (10.3%). For the study, the team considered the heart rate dynamics of all sounds made by the baby’s mouth, be it a laugh, a babble or a coo.
“Every sound an infant makes helps their brain and body learn how to coordinate with each other, eventually leading to speech,” Borjon said.
As infants grow, their autonomic nervous system grows and develops. The first few years of life are marked by significant changes in how the heart and lungs function, and these changes continue throughout a person’s life.
The relationship between recognisable vocalisations and decelerating heart rate may imply that the successful development of speech partially depends on infants experiencing predictable ranges of autonomic activity through development.
“Understanding how the autonomic nervous system relates to infant vocalisations over development is a critical avenue of future research for understanding how language emerges, as well as risk factors for atypical language development,” said Borjon
The foundation for healthy eating behaviour starts in infancy. Young children learn to regulate their appetite through a combination of biological, psychological, and sociological factors. In a new paper published in Social Science & Medicine, researchers at the University of Illinois Urbana-Champaign propose a model that explores these factors and their interactions, providing guidelines for better understanding childhood appetite self-regulation.
Appetite self-regulation is related to general self-regulation, but it specifically concerns an individual’s ability to regulate food intake, which affects healthy development and obesity risk. Children are born with a capacity to regulate appetite based on hunger and satiety signals, but with increased exposure to environmental factors, their eating is increasingly guided by psychological reasoning and motivations. Therefore, it is important to take a developmental perspective to trace changes in eating behaviours over time, Ju stated.
Ju and her colleagues provide a comprehensive framework based on the biopsychosocial pathways model, which outlines three interacting categories: Biological factors, including sensory experience, physiological hunger and satiety signals, brain-gut interaction, and the influence of the gut microbiome; psychological factors, including emotional self-regulation, cognitive control, stress regulation, and reward processing;and social factors, such as parental behaviour and feeding practices, culture, geographic location, and food insecurity.
The researchers combine this framework with temperamental theory to explore how the pathways are modified by individual temperament.
Children react differently to stimuli based on their psychological and emotional make up, Ju explained. For example, openness to novelty and positive anticipation can affect whether a child is willing to try new foods. If a parent pressures their child to eat, it could be counter-productive for a child with heightened sensitivity to negative affect, causing the child to consume less.
The model also takes children’s developmental stages into account. Infants have basic appetite regulation based on physiological cues. They gradually become more susceptible to external influences and by age 3-5, children begin to exhibit greater self-control and emotional regulation.
“By analysing the pathways outlined in our model, we can better understand the combined influences of multiple factors on children’s appetite self-regulation and their motivations to approach food,” Ju said. “For example, the presence of palatable food may not generate similar responses in everyone. Children could approach food as a reward, for pleasure-seeking, or to regulate emotions. The underlying motivations can be diverse, and they are influenced by external factors as well as temperamental characteristics.”
Socio-environmental influences include parent-child interactions around food, as well as non-food-related caregiver practices that can impact the child’s emotional regulation. The household food environment, cultural value of food intake, and food availability are also important factors, the researchers stated.
“If we understand the differential susceptibility to various factors, we can identify and modify the environmental influences that are particularly obesogenic based on children’s temperamental characteristics. Then we will be able to provide more refined approaches to support children’s healthy eating behaviour,” Ju explained.
The average age at menarche, the first menstrual period, has been decreasing among younger generations in the US, especially those belonging to racial minorities and lower socioeconomic statuses, according to a new study led by researchers at Harvard T.H. Chan School of Public Health. It also found that the average time it takes for the menstrual cycle to become regular is increasing.
The study, published in JAMA Network Open, is the latest publication from the Apple Women’s Health Study, a longitudinal study of menstrual cycles, gynaecological conditions, and overall women’s health conducted by Harvard Chan School, the National Institute of Environmental Health Sciences, and Apple.
“Our findings can lead to a better understanding of menstrual health across the lifespan and how our lived environment impacts this critical vital sign,” said co-principal investigator Shruthi Mahalingaiah, assistant professor of environmental, reproductive, and women’s health at Harvard Chan School.
While previous studies have shown trends towards earlier menarche over the past five decades, data has been limited on how these trends present within different racial groups and socioeconomic statuses. Additionally, few studies have had sufficient data to identify any trends regarding time to menstrual cycle regularity.
The researchers used the Apple Women’s Health Study’s large, diverse dataset to fill this research gap. The 71 341 participants who enrolled between November 2018 and March 2023 self-reported the age at which they first began menstruating and their race and socioeconomic status. The researchers divided the participants into five age brackets: born between 1950–1969, 1970–1979, 1980–1989, 1990–1999, and 2000-2005. Ages of menarche were defined as early (younger than 11 years old), very early (younger than 9), and late (ages 16 and above). A subset of participants (61 932) self-reported the time it took for their menstrual cycle to become regular and were divided into five categories: up to two years, between three and four years, longer than five years, hasn’t become regular, or became regular with use of hormones. Another subset (9865) provided their body mass index (BMI) at their age of menarche.
The study found that as birth year increased (meaning younger participants), average age at menarche decreased and time from menarche to menstrual cycle regularity increased. Among participants born from 1950–1969, the average age at menarche was 12.5 years, and the rates of early and very early menarche were 8.6% and 0.6%, respectively. Among participants born from 2000–2005, the average age of menarche was 11.9 years, and the rates of early and very early menarche were 15.5% and 1.4%, respectively. Across the two groups, the percentage of participants who reached menstrual cycle regularity within two years of menarche decreased from 76% to 56%. The researchers observed that these trends were present among all sociodemographic groups but were most pronounced among the participants who identified as Black, Hispanic, Asian, or mixed race, and who rated themselves as belonging to a low socioeconomic status.
The findings showed that BMI at age of menarche could explain part of the trend toward periods starting earlier. Other possible factors that might explain the trend include dietary patterns, psychological stress and adverse childhood experiences, and environmental factors such as endocrine-disrupting chemicals and air pollution.
“Continuing to investigate early menarche and its drivers is critical,” said corresponding author Zifan Wang, postdoctoral research fellow in Harvard Chan School’s Department of Environmental Health. “Early menarche is associated with higher risk of adverse health outcomes, such as cardiovascular disease and cancer. To address these health concerns – which our findings suggest may begin to impact more people, with disproportionate impact on already disadvantaged populations – we need much more investment in menstrual health research.”
The authors noted some limitations to the study, including that it relies heavily on retrospective self-reporting.
The “Thrive 5” are five conditions to ensure an infant in the first year of life has what they need for healthy development. Those conditions include environmental stimulation, nutrition, neighbourhood safety, positive caregiving and regular circadian rhythms and sleep. Simple, and yet, it has not yet been prioritised for many reasons including the fact that researchers had not provided empirical data to support making the Thrive 5 a public health priority.
Researchers at Washington University in St. Louis think it’s time to change that. In new research published in JAMA Pediatrics, Deanna Barch and Joan Luby make the case that “Thrive Factor” is a key element of healthy human brain, behavioural and cognitive development.
“When they have access to these basic supports, even in the face of adverse environments, it enhances their brain development, cognition (measures of IQ) and social-emotional development,” said Luby, MD, the university’s Samuel and Mae S. Ludwig Professor of Child Psychiatry at the School of Medicine.
There have been plenty of studies touting the benefits of individual thrive factors, such as encouraging breast-feeding to facilitate growth in general, but this new study looks at several key factors known to influence brain development and shows their relationship to outcomes at age 3.
“The novelty here is putting them all together and thinking of them as a constellation of things that are necessary and important for a child to be able to thrive,” said Barch, PhD, vice dean of research, a professor of psychological & brain sciences in Arts & Sciences and the Gregory B. Couch Professor of Psychiatry at the School of Medicine.
The study is part of a change in thinking in the child development field as scientists have learned that much of our health is not just genetically predetermined but is powerfully influenced by the psychosocial environment. The human brain is still undergoing rapid development at birth, and researchers are trying to understand the environmental factors that shape this development.
The study of 232 infants and their mothers looked at positive factors in the environment in the foetal period and first year of life that enhance brain development, minimise negative behaviours and increase cognitive outcomes. Participants were evaluated on social disadvantage indexes beginning in utero and early life T-Factor scores were also calculated. As infants approached age 3, they were re-evaluated for social, emotional and cognitive development along with using MRIs to scan brain structure.
The results were clear that T-Factor is powerful: Even infants coming from adverse conditions and under-resourced backgrounds can have healthy development if they get their Thrive 5.
The researchers note that policymakers and paediatric primary care providers should be informed about the importance of focusing on elements of the T-Factor and how they can lead to many downstream advantages for both the child and society.
It may seem obvious to anyone that a baby needs care, sleep, food, stimulation and safety but “nobody has particularly focused on or prioritised the importance of this during foetal development and in the first year of life to enhance critical developmental outcomes,” Luby said.
“The Thrive Factor provides a solid foundation for healthy development. It has been underappreciated in primary care just how malleable the brain is to experience,” Luby added.
Barch said the next step will be setting up interventions to test in randomised controlled trials. Another advantage to T-Factor is it is highly feasible to share and promote in broad populations.
Interventions would likely take the form of multiple Zoom sessions with parents to educate and coach them on how to best provide each thrive factor. But that would just be the start, since parents need resources to help them provide thrive factors.
Though T-Factor can help kids overcome adverse conditions, Barch emphasised the need for understanding just how tough those adverse conditions can be on a new parent.
“If you’ve never suffered from financial adversity, you don’t understand how hard that makes life,” she said.
Parents can struggle to provide conditions to thrive because they may have to support many people in their household, may not have adequate number of rooms to ensure easier child sleep training, must work multiple jobs and can’t get away to breast feed, and live in unsafe neighbourhoods that keep them in a constant state of vigilance.
Though education can help caregivers, it will take public policy interventions to ensure parents can access all the Thrive Factors, especially when it comes to access to safe housing and adequate income to support even these basic needs of developing infants.
“We need to make it so families can have the resources necessary to provide these core things to kids because it’s going to have such a big impact on kids’ development across the course of their lifespan,” she said.
As childhood obesity increases the world, children are entering puberty earlier and earlier – particularly girls. According to a survey, the onset of puberty occurs on average three months earlier for girls in every decade since 1977. Early, or precocious, puberty can leave children with psychological and social problems, as well leading to shorter adult heights. Studies also suggest that early puberty can increase the risk of developing cancer, diabetes, depression and cardiovascular disease later on in life.
While a scientific explanation has been lacking, the link between childhood obesity and early puberty has long been apparent. The more body fat a child has, the greater their likelihood of beginning puberty at an earlier age. Now, researchers have found what may be part of the answer in Drosphila fruit flies, publishing their results in Current Biology.
“Cholesterol is a fat. So, if you’re overweight, your body fat harbours more cholesterol. And it turns out that higher cholesterol is a key to earlier maturation in the fruit fly, our model organism. Our results demonstrate that the amount of cholesterol in adipose tissue and in certain support cells in the brain affects the growth of fruit flies and controls when they reach maturity,” explains Professor Kim Rewitz, a lead author of the study.
He adds, “And because the systems in fruit flies and humans are remarkably similar, we believe that the same may apply to humans – ie, that cholesterol in adipose tissue may help explain the connection between childhood obesity and early puberty.”
Puberty at ‘critical weight’
Professor Rewitz and the University of Copenhagen’s Department of Biology research team tested their hypothesis by putting fruit fly larvae on a “fatty diet” of cholesterol-packed foods. The development of these larvae was compared with larvae on a normal diet.
“We observed that larvae on the cholesterol diet consistently grew faster and entered ‘puberty’ sooner. It turned out that the increase of cholesterol stored in the fruit flies’ body fat and support cells in the brain increases the release of growth hormones that cause the animals to grow faster. Growth and size is a signal to the body for when to trigger puberty,” says Kim Rewitz.
The professor explains that in fruit flies, the signal to undergo maturation is when their weight and amount of body fat reach a certain point during development:
“In one way or another, animals need to know when they’re large enough to reach sexual maturity and be able to reproduce. Organisms have a checkpoint in their development that they must pass to enter puberty known as ‘Critical Weight’. This checkpoint is found in fruit flies and most likely in humans too. This means that both fruit fly larvae and children probably need to reach a certain body size and have a certain amount of fat stored to enter puberty. What we’ve found is that the amount of cholesterol stored in body fat plays an important role in this process.
“We see that fruit flies have a mechanism that senses how much cholesterol is stored in their body fat and support cells in the brain. At a certain point, the system then sends a signal to the brain centres that triggers maturation by producing steroid hormones. In humans, these correspond to testosterone and oestrogen.”
However, it also means that if the amount of stored cholesterol increases, the organism can actually fail to estimate its overall size accurately, so that it hits the critical weight checkpoint earlier than it normally would:
“Because overweight children have more body fat, they will probably also have stored more cholesterol at an earlier point in their development. So, if our assumption that the same mechanism exists in humans holds true, it could help to explain early puberty in obese children,” says the researcher.
Cholesterol may influence cancer as well
Professor Rewitz concludes that with part of the puzzle in hand, scientists can search for more clues and treatment. In the meantime, lifestyle changes remain the best solution for childhood obesity.
Professor Rewitz and his research colleagues have now started to look deeper into the significance of the cholesterol mechanism for cancer development. Their research also shows that, via the same mechanism, cholesterol can activate cell growth that leads to cancer.
Children around the world are spending more and more time with screens, which is a great concern for parents and physicians alike. New research from Japan indicates that more screen time at age 2 is associated with poorer communication and daily living skills at age 4 – but playing outdoor seems to reduce some of the negative effects.
For their study, published in JAMA Pediatrics, the researchers followed 885 children from 18 months to 4 years of age. They looked at the relationship between three key features: average amount of screen time per day at age 2, amount of outdoor play at age 2 years 8 months, and neurodevelopmental outcomes at age 4: communication, daily living skills, and socialization scores according to a standardised assessment tool called Vineland Adaptive Behavior Scale-II.
“Although both communication and daily living skills were worse in 4-year-old children who had had more screen time at aged 2, outdoor play time had very different effects on these two neurodevelopmental outcomes,” explains Kenji J. Tsuchiya, Professor at Osaka University and lead author of the study. “We were surprised to find that outdoor play didn’t really alter the negative effects of screen time on communication – but it did have an effect on daily living skills.”
Specifically, almost one-fifth of the effects of screen time on daily living skills were mediated by outdoor play, meaning that increasing outdoor play time could reduce the negative effects of screen time on daily living skills by almost 20%. The researchers also found that, although it was not linked to screen time, socialisation was better in 4-year-olds who had spent more time playing outside at 2 years 8 months of age.
“Taken together, our findings indicate that optimizing screen time in young children is really important for appropriate neurodevelopment,” says Tomoko Nishimura, senior author of the study. “We also found that screen time is not related to social outcomes, and that even if screen time is relatively high, encouraging more outdoor play time might help to keep kids healthy and developing appropriately.”
These results are particularly important given the recent COVID-related lockdowns around the world, which have generally led to more screen time and less outdoor time for children. Because the use of digital devices is difficult to avoid even in very young children, further research looking at how to balance the risks and benefits of screen time in young children is eagerly awaited.
