Robust evidence supports paracetamol’s (acetaminophen - Tylenol) safety during pregnancy

 Researchers from the LKS Faculty of Medicine at the University of Hong Kong (HKUMed) have found that using a commonly used pain killer (paracetamol or acetaminophen) during pregnancy does not increase the risk of autism spectrum disorder (ASD) or attention‑deficit/ hyperactivity disorder (ADHD) in children. This represents the first study in Hong Kong to apply a rigorous sibling-matched approach to compare siblings from the same mother to effectively account for shared genetic and environmental influences. The findings, published in JAMA Internal Medicine [link to the publication], offer timely reassurance for expectant mothers and clinicians in Hong Kong and globally regarding the safety of paracetamol use during pregnancy.

Addressing global anxiety: the paracetamol debate
Paracetamol is the most widely used medication for pain and fever during pregnancy. However, concerns about its potential association with ASD and ADHD have intensified following overseas reports and policy discussions. While international health authorities, including the World Health Organization and the Department of Health in Hong Kong, have reaffirmed its safety profile, robust local evidence was previously lacking – a gap that this study has now filled.

Sibling-matched analysis accounts for shared familial factors
Some previous studies suggested a modest increase in ASD and ADHD risk in offspring but did not fully account for differences between mothers who did and did not use paracetamol, such as underlying health status, lifestyle or familial factors. To address these methodological limitations, the HKUMed team analysed electronic medical records from 708,020 mother–child pairs in Hong Kong between 2000 and 2023, allowing a more comprehensive and accurate assessment.

Initial analyses without sibling matching reproduced earlier findings of a slight increase in risk. However, when the researchers applied a sibling-matched design—comparing siblings exposed and unexposed to paracetamol during mothers’ pregnancy—no association was observed between prenatal paracetamol exposure and the risk of ASD or ADHD in their offspring. These findings remained consistent regardless of dosage, timing of exposure (across all trimesters), and pattern of use (sporadic, intermittent or persistent).

Robust evidence supports paracetamol’s safety during pregnancy
Dr April Luo Shan, Research Assistant Professor in the Department of Family Medicine and Primary Care, School of Clinical Medicine, HKUMed, said: ‘I had herpes zoster during my pregnancy, but I did not take paracetamol at that time because of concerns raised in the media. As both a researcher and a mother, I deeply understand the anxiety many women face. Our study provides the reassurance I wish I had and would have helped me manage the pain I was experiencing.’

Professor Peter Tanuseputro, Clinical Professor in the same department, added, ‘Previous conflicting studies generated doubt and unnecessary stress for expectant parents, leading many mothers to endure untreated pain or resort to other medications that may be less safe. Our sibling-matched study within a massive Chinese cohort provides robust evidence that paracetamol is safe during pregnancy.’

Professor Ian Wong Chi-kei, Professor in the Department of Pharmacology and Pharmacy, HKUMed, added. ‘Monitoring the long-term outcomes of children with in-utero drug exposure requires an incredibly robust data infrastructure. Thanks to the Laboratory of Data Discovery for Health (D24H) at AIR@InnoHK, the Research Grants Council and Hospital Authority, we were able to rapidly address this urgent drug safety question with the necessary precision and scale.’

Mediterranean diet is associated with better psychological well-being

Following a Mediterranean diet may provide additional benefits for mental health. A new study has now linked it to greater psychological well-being among people over the age of 50. The research is the result of a collaboration between University College London and the Barcelona Institute for Global Health (ISGlobal), a centre supported by the ”la Caixa” Foundation, and has been published in BMJ Open.

To date, numerous studies have shown that the Mediterranean diet—rich in fruits, vegetables, legumes, fish and olive oil—is an effective shield against physical decline and the development of disorders such as depression. However, this new study goes a step further by focusing on positive psychological well-being, which encompasses dimensions such as control, autonomy, pleasure and self-realisation, and includes questions relating to independence, enjoyment of life, sense of purpose, energy levels and future outlook. The study suggests that the benefits of following a Mediterranean diet for well-being are independent of the presence of depressive symptoms or the participants’ socioeconomic status.

The study analysed data from 3,296 individuals aged between 50 and 90 years who were participating in the English Longitudinal Study of Ageing (ELSA). Dietary habits were assessed between 2018 and 2019 using an online platform, where participants reported everything they had eaten and drunk on two non-consecutive days. Psychological well-being was evaluated through questionnaires administered on up to two occasions between 2018 and 2020.

Protection against the mental health effects of COVID-19

Data collected through the ELSA cohort show that the emergence of the COVID-19 pandemic and the restrictive measures that followed had a negative emotional impact on study participants. However, the decline in emotional well-being was less pronounced among individuals with greater adherence to the Mediterranean diet, suggesting a protective effect.

“Our study is observational and, therefore, the results should be interpreted with caution, since we cannot draw causal conclusions,” says Camille Lassale, ISGlobal researcher and senior author of the study. “Nevertheless, the questionnaires administered during the pandemic allowed us to follow participants over time, which is a major strength of the study. Although the biological mechanisms underlying the relationship between the Mediterranean diet and better mental health are still being investigated, the evidence suggests that its foundational foods and components help regulate key processes such as stress responses, inflammation, gut health and brain function”, she adds.

“This study provides further evidence of the relationship between what we eat and our mental health, an emerging field of research that we hope will generate substantial new evidence in the years to come,” says Alanna Shand, research psychologist and co-author of the study.

“Although many questions remain open, there is no doubt about the need to promote healthy lifestyles, prioritising a balanced diet rich in plant-based foods and low in foods such as processed meats and sweets, particularly among older adults,” says Andrew Steptoe, researcher at University College London and first author of the study.

Reference

Steptoe A, Shand AJ, Lassale C. Adherence to the Mediterranean diet and psychological wellbeing before and during the COVID-19 pandemic: a prospective analysis of the English Longitudinal Study of Ageing. BMJ Open. 2026; 16(6): e109599. http://dx.doi.org/10.1136/bmjopen-2025-109599

Study links birth control pills to more binge eating

 

Emotional eating increased when women were taking hormone-containing birth control pills compared to the hormone-free pills taken at the end of each monthly cycle

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Birth control pills are safe and effective for millions of women, but researchers are still working to understand how the hormones they contain may influence eating behavior.

A new study in JAMA Network Open followed 422 women who were already using combined oral contraceptives, tracking their eating patterns daily for 49 consecutive days. The goal: to examine whether binge-related eating changes depending on whether women are taking hormone-containing pills or hormone-free pills within the same cycle.

In a typical birth control pack, women take about three weeks of “active” pills that contain hormones, followed by about a week of “inactive” pills that contain no hormones.

“Because we tracked the same women day to day, we could see how eating changed with hormone exposure,” said Dr. Shaunna Clark, a co-author and associate professor of psychiatry and behavioral sciences at Texas A&M University’s Naresh K. Vashisht College of Medicine.

How birth control hormones may increase binge-eating risk

The study used a within-person design, meaning each participant served as her own comparison. Researchers measured emotional eating (overeating in response to negative emotions) while tracking whether each day corresponded to an active or inactive pill.

They found a consistent pattern:

Emotional eating was significantly higher during active pill days than during inactive pill days.

This pattern appeared:

• across two full pill cycles
• in the full sample of 422 women
• and in a subset of women with diagnosed binge eating

Clark says the findings held even after accounting for negative mood, suggesting the change was not fully explained by emotional distress.

“That tells us the hormones themselves may be playing a role, rather than those changes being driven by mood or other factors,” she said.

Why birth control may increase binge-eating risk for some women, but not others

The analysis focused on average changes across the group, but the study emphasizes that not all women experience these shifts in the same way.

“Participants ranged in age from late adolescence to young adulthood and were all using the same type of pill, monophasic combined oral contraceptives, which provide a consistent dose of hormones during active pill days,” said Clark, part of the research team led by Dr. Kelly Klump at Michigan State University.

Because the study examined within-person changes, it shows that eating behavior can shift alongside hormone exposure, even if the magnitude of that shift differs between individuals.

“These findings show a pattern at the group level,” she said, “but individual responses can vary.”

Birth control pills linked to binge eating, but not mood or body image

The study does not establish that birth control pills cause binge eating. Instead, it identifies a specific association between hormone exposure and increased emotional eating within individuals.

Importantly, researchers also tested other outcomes:

• Weight preoccupation did not change across pill type
• Mood changes in response to pill type were smaller and less consistent than the changes in eating

Clark says that suggests the effect is relatively specific to binge-related eating behavior, rather than a general shift in mood or body image concerns.

How this study changes what we know about birth control and binge eating

Previous research has shown that binge‑related eating tends to increase after ovulation, when both estrogen and progesterone are elevated.

This study extends that work by showing that synthetic hormones in birth control pills are linked to similar patterns.

By comparing hormone-containing and hormone-free days within the same individuals, the study provides some of the clearest evidence to date that binge-related eating increases during periods of hormone exposure in the birth control cycle.

“Findings like these can help us better understand how different hormone exposures affect eating behavior,” Clark said. “Over time, that could help clinicians and patients make more informed decisions about care.”

Skimping on sleep leads to weight gain

People who shortened their sleep by around 80 minutes a night for six weeks gained weight—one pound on average—and were more sedentary, researchers at Columbia University Vagelos College of Physicians and Surgeons have found.

“Our study shows that getting adequate sleep may help reduce the risk of weight gain and obesity-related conditions like heart disease and diabetes,” says Marie-Pierre St-Onge, a professor of nutritional medicine in Columbia’s Department of Medicine and Institute for Human Nutrition and study leader. “People tend to gain weight over the course of their adulthood, and obesity is a major risk factor for heart disease. But focusing on eating a healthier diet and getting more physical activity to offset weight gain is simplistic and can be difficult to maintain.” 

Studying the effects of chronic, mild sleep deficits

Much of what's known about the link between insufficient sleep and obesity is based on small, brief studies of people who endured severe sleep restriction (usually 4 hours of sleep opportunity). Such studies show that severe sleep deprivation leads to changes in appetite and overeating, which can contribute to weight gain over time.

But most people cannot tolerate severe sleep deprivation for more than a few days.

“These studies only show us what happens under the most extreme conditions and don’t tell us if mildly sleep-deprived people, like a lot of Americans who get 5 or 6 hours of sleep a night, will gain weight,” St-Onge says. 

Six weeks of short sleep = 1 extra pound

To investigate the effects of chronic mild sleep deprivation, a sleep pattern adopted by roughly 30% of adults, St-Onge and her team recruited 95 adults who usually get 7-8 hours of sleep. Participants were instructed to delay their normal bedtime by 90 minutes for one six-week phase and to get the usual amount of sleep for another six-week phase. Sleep and activity levels were measured throughout each phase with a wrist monitor, along with changes in body weight, waist circumference, body composition, and fasting levels of several hormones known to increase or suppress appetite.

“While the one-pound weight gain observed with modest sleep curtailment is not overwhelming, it is important to remember this is occurring over just six weeks,” says Faris Zuraikat, assistant professor of nutritional medicine in Columbia’s Department of Medicine and Institute for Human Nutrition and first author of the study. “Our study was designed to mimic sleep patterns that most adults experience chronically. When extrapolated to a full year, we would expect that losing less than an hour and a half of sleep per night could result in clinically meaningful weight gain.”

Sedentary time also increased by an average of 17 minutes per day during the sleep-restriction phase overall, and by nearly 30 minutes per day for men and postmenopausal women.  

“Even when we accounted for the fact that they were awake longer when sleep was shortened, participants spent more time being inactive than when they got adequate sleep,” Zuraikat says. “This is notable, as people who are more sedentary have elevated risk for chronic diseases.”

Why does mild sleep deprivation cause weight gain?

In a previous, related study of a sub-set of the same participants, St-Onge's team reported that women with increased cardiometabolic risk who shortened their sleep by around 80 minutes a night over six weeks had increased insulin resistance, a risk factor for type 2 diabetes. The effects were more pronounced in postmenopausal women.

In another study of this group, St-Onge found that men and women with elevated heart risk had an influx of inflammatory cells in the heart after mild sleep restriction.

“Though more research is needed to further understand how sleep restriction leads to weight gain, all of our findings suggest that insufficient sleep increases the risk of obesity-related conditions like type 2 diabetes and heart disease,” St-Onge says. “Now we need to understand the health effects of improving sleep in those who fail to get adequate sleep on a regular basis.”  

Intermittent fasting maintains long-term weight loss, regardless of meal timing

 

The study, in which the University of Granada (UGR) participated and which was recently published in the journal *Clinical Nutrition*, involved 99 adults—half of whom were women—who were overweight or obese

Peer-Reviewed Publication

University of Granada

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The study, in which the University of Granada (UGR) participated and which was recently published in the journal Clinical Nutrition, involved 99 adults—half of whom were women—who were overweight or obese

A team of scientists from the University of Granada (UGR), the Granada Institute for Biomedical Research (ibs.GRANADA), the Public University of Navarra, and the Biomedical Research Networking Center (CIBER) has demonstrated that limiting food intake to an eight-hour window helps maintain weight loss 12 months after the end of the intervention in overweight or obese adults.

The research has revealed that intermittent fasting—specifically the method popularly known as 16:8, in which participants fast for 16 hours and are allowed to eat during the remaining eight hours—is an effective strategy for maintaining weight loss in the medium term. The study shows that these benefits persist one year later regardless of whether the eight-hour eating window occurs early in the day (between 9 a.m. and 5 p.m., known as early fasting) or later (between 1 p.m. and 9 p.m., known as late fasting), compared to people who maintain their usual eating routine for 12 hours or more.

The results show that both the early-fasting and late-fasting groups managed to maintain significantly greater weight loss after 12 months. Furthermore, the early-fasting group maintained a greater reduction in fat mass. According to the researchers, these findings suggest that this type of nutritional intervention is not only feasible and effective in the short term but now also demonstrates sustainable effects over time.

Body Composition Assessment One Year Later

The study, recently published in the prestigious journal *Clinical Nutrition*, the official journal of the European Society for Clinical Nutrition and Metabolism, involved 99 adults—half of whom were women—who were overweight or obese. During the first 12 weeks, participants were divided into four groups, all of which followed a Mediterranean diet education program: a control group that maintained its usual eating window (12 hours or longer), an early fasting group (an 8-hour window beginning before 10:00 a.m.), a late fasting group (an 8-hour window beginning after 1:00 p.m.), and a self-selected group where participants chose their own 8-hour eating window.

Changes in weight, fat mass, and fat-free mass were measured before and after the 12-week intervention, as well as one year after the study ended. This study is part of a larger project whose main results have been published in the prestigious journal *Nature Medicine*, where it was observed that participants who practiced TRE, regardless of their eating schedule, lost an average of 3–4 kilos more than the group that received only nutritional recommendations.

Dr. Alba Camacho Cardeñosa, a researcher at the University Joint Institute for Sport and Health (iMUDS) at the University of Granada (UGR) and a postdoctoral fellow at ibs.GRANADA in the Endocrinology and Nutrition Department at San Cecilio University Clinical Hospital, is the study’s first author. She explains that “to date, although we knew that intermittent fasting promotes modest weight loss in the short term, it was unclear whether its effects were sustained over time. By evaluating the participants 12 months after the intervention ended, we demonstrated that the changes in body weight persist.” In addition, the researchers highlight that “a very positive finding is that one in three people decided to continue practicing intermittent fasting on their own during that year of follow-up, suggesting that it is a relatively easy habit to integrate into daily life.”

A Flexible Strategy Against Obesity

The study was led by researchers from ibs.GRANADA belonging to the PROFITH CTS-977 research group at the University of Granada (UGR), headed by Professor Jonatan Ruiz Ruiz, in collaboration with the San Cecilio University Clinical Hospital and the Virgen de las Nieves University Hospital in Granada, the Public University of Navarra, the CIBER on Obesity (CIBEROBN), and the CIBER on Frailty and Healthy Aging (CIBERFES).

The researchers emphasize that an intervention involving just 12 weeks of intermittent fasting may represent an effective medium-term strategy for weight control in overweight or obese adults. Since both early- and late-day fasting regimens have been shown to be effective, the findings offer valuable flexibility for patients to choose the schedule that best suits their lifestyle, thereby improving adherence and success in obesity treatment.

The MP20 group—Biomarkers of Metabolic and Bone Diseases at ibs.GRANADA—investigates biomarkers and new therapeutic targets for metabolic, bone, and cardiovascular diseases. It combines bioinformatics and clinical techniques to develop diagnostic tools and evaluate treatments. Among its findings, the group highlights the role of intermittent fasting as a treatment for obesity and its comorbidities, as well as the use of bone markers in predicting cardiovascular risk. Its multidisciplinary and collaborative approach drives high-impact research with clinical applications.

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Journal

Clinical Nutrition

DOI

10.1016/j.clnu.2026.106706 

Method of Research

Randomized controlled/clinical trial

High fructose during pregnancy impairs fetal brain

 Nutritional imbalance during pregnancy can have long-lasting effects on the health status and disease susceptibility of the offspring. As such, high fructose intake through sweetened food and beverages in pregnant women has been associated with an increased susceptibility to diabetes and cardiovascular disease, as well as neurological and cognitive impairments in the offspring. Currently, it is not well understood how early life exposure to fructose has such long-lasting effects on the cellular and molecular level.  

In a recent paper published in Stem Cell Reports, Hiroya Yamada’s team from Fujita Health University School of Medicine, Toyoake, Japan found that the performance of adult rats in learning and memory tests was impaired when the rats had been exposed to high fructose in before birth by feeding their mothers with high fructose corn syrup. Furthermore, neurogenesis, which is the generation of new neurons from neural stem cells (NSCs), in distinct regions of the brain involved in learning and cognition was reduced in those rats. Further, Yamada’s group discovered distinct changes in NSCs after high fructose exposure, which included reduced cell division and impaired generation of new neurons, and altered gene expression. To explain why prenatal high fructose exposure can have such long-lasting effects on NSCs, the researchers profiled the so-called epigenetic changes, which are chemical imprints on the DNA controlling gene activity. Strikingly, prenatal high fructose exposure introduced distinct epigenetic changes in fetal NSCs which persisted into adulthood and which deregulated the activity of genes important for adult neurogenesis.  Restoring normal expression of those genes improved the function of high fructose-exposed NSCs.

This research illustrates how early-life exposure to an adverse environment, e.g. an imbalanced maternal nutrition, can have long-lasting effects on brain development and function by changing the epigenetic regulation of gene activity in NSCs. Importantly, although epidemiological studies in human populations show similar correlations, further studies will be required to test if human NSCs are affected by high fructose and other environmental stressors in similar ways. “Our study suggests that neural stem cells may retain a biological memory of maternal nutrition during pregnancy," said Dr. Yamada. "This may help explain how a transient prenatal dietary imbalance can lead to long-lasting changes in brain development and function."

Prolonged sedentary behavior associated with increased cancer risk

 

Each additional hour of prolonged, uninterrupted sedentary behavior in a person's day is associated with a 9% higher risk of cancer death, according to a study published July 2nd in the open access journal PLOS Medicine by Frederick Ho of the University of Glasgow, UK, and colleagues.

Previous studies have shown that spending more total time on sedentary behavior, such as sitting, reclining or lying down while awake, is linked to poorer health outcomes. However, most sedentary behavior guidelines focus on total time spent sedentary, rather than whether that time is accumulated in many short intervals or fewer prolonged intervals.

In the new study, researchers analyzed data from 91,292 UK Biobank participants who had worn activity monitors for 7 days and were followed for a median of 12.38 years afterward. Activity was categorized as either prolonged sedentary (bouts of at least 30 minutes with at least 90% of time sedentary), interrupted sedentary behavior (which lasted less than 30 minutes or was broken up with more than 10% non-sedentary time), or varying degrees of physical activity.

Prolonged sedentary behavior was associated with a higher risk of cancer mortality (HR 1.09; 95% CI 1.06, 1.11), overall cancer incidence, obesity-related cancers (such as esophageal, liver, kidney, pancreatic, colorectal, breast, ovarian, and thyroid cancers), and type 2 diabetes-related cancers. Interrupted sedentary behavior showed the opposite pattern, associated with lower risk across all outcomes. Replacing one hour per day of prolonged sedentary behavior with light physical activity was associated with a 12% lower risk of cancer death (HR 0.88; 95% CI 0.79, 0.99).

As a single-cohort study of UK Biobank volunteers, who have known health volunteer bias and higher physical activity levels than the general UK population, the findings may not be generalizable and do not prove causality. The researchers also had no data on the context of sedentary behavior, such as whether it was during work or driving.

“Our findings suggest that the health effects of sedentary behavior may depend not only on total sedentary time, but also on whether that time is accumulated in prolonged bouts or interrupted by activity,” the authors say. “This pattern is biologically plausible: experimental studies have shown that interrupting prolonged sitting with short bouts of activity can improve metabolic responses compared with uninterrupted sitting.”

The authors add, “Current health guidelines focus heavily on moderate or vigorous exercise, but our findings show that light movement shouldn't be ignored. Moving forward, clinical trials will help us move beyond blanket advice and develop personalised strategies for breaking up sitting time.”

In your coverage, please use this URL to provide access to the freely available paper in PLOS Medicine: https://plos.io/4oi0sJO