A new study from McGill University finds that a high-salt diet triggers brain inflammation that drives up blood pressure.
The research, led by Masha Prager-Khoutorsky in collaboration with an interdisciplinary team at McGill and the Research Institute of the McGill University Health Centre, suggests the brain may be a missing link in certain forms of hypertension traditionally attributed to the kidneys.
“This is new evidence that high blood pressure can originate in the brain, opening the door for developing treatments that act on the brain,” said Prager-Khoutorsky, associate professor in McGill’s Department of Physiology.
Hypertension affects two-thirds of people over 60 and contributes to 10 million deaths worldwide each year. Often symptomless, the condition increases the risk of heart disease, stroke and other serious health problems.
About one-third of patients don’t respond to standard medications, which primarily target the blood vessels and kidneys based on the long-standing view that hypertension begins there. The study, published in the journal Neuron, suggests the brain may also be a key driver of the condition, particularly in treatment-resistant cases.
How salt disrupts the brain
To mimic human eating patterns, rats were given water containing two per cent salt, comparable to a daily diet high in fast food and items like bacon, instant noodles and processed cheese.
The high-salt diet activated immune cells in a specific brain region, causing inflammation and a surge in the hormone vasopressin, which raises blood pressure. Researchers tracked these changes using cutting-edge brain imaging and lab techniques that only recently became available.
“The brain’s role in hypertension has largely been overlooked, in part because it’s harder to study,” Prager-Khoutorsky said. “But with new techniques, we’re able to see these changes in action.”
The researchers used rats instead of the more commonly studied mice because rats regulate salt and water more like humans. That makes the findings more likely to apply to people, noted Prager-Khoutorsky.
Next, the scientists plan to study whether similar processes are involved in other forms of hypertension.
The brain controls the release of glucose in a wide range of stressful circumstances, including fasting and low blood sugar levels.
However, less attention has been paid to its role in day-to-day situations.
In a study published in Molecular Metabolism, University of Michigan researchers have shown that a specific population of neurons in the hypothalamus help the brain maintain blood glucose levels under routine circumstances.
Over the past five decades, researchers have shown that dysfunction of the nervous system can lead to fluctuations in blood glucose levels, especially in patients with diabetes.
Some of these neurons are in the ventromedial nucleus of the hypothalamus, a region of the brain that controls hunger, fear, temperature regulation and sexual activity.
“Most studies have shown that this region is involved in raising blood sugar during emergencies,” said Alison Affinati, MD, PhD, assistant professor of internal medicine and member of Caswell Diabetes Institute.
“We wanted to understand whether it is also important in controlling blood sugar during day-to-day activities because that’s when diabetes develops.”
The group focused on VMHCckbr neurons, which contain a protein called the cholecystokinin b receptor.
They used mouse models in which these neurons were inactivated.
By monitoring the blood glucose levels, the researchers found that VMHCckbr neurons play an important role in maintaining glucose during normal activities, including the early part of the fasting period between the last meal of the day and waking up in the morning.
“In the first four hours after you go to bed, these neurons ensure that you have enough glucose so that you don’t become hypoglycaemic overnight,” Affinati said.
To do so, the neurons direct the body to burn fat through a process called lipolysis.
The fats are broken down to produce glycerol, which is used to make sugar.
When the group activated the VMHCckbr neurons in mice, the animals had increased glycerol levels in their bodies.
These findings could explain what happens in patients with prediabetes, since they show an increase in lipolysis during the night.
The researchers believe that in these patients, the VMHCckbr neurons could be overactive, contributing to higher blood sugar.
These nerve cells, however, only controlled lipolysis, which raises the possibility that other cells might be controlling glucose levels through different mechanisms.
“Our studies show that the control of glucose is not an on-or-off switch as previously thought,” Affinati said.
“Different populations of neurons work together, and everything gets turned on in an emergency. However, under routine conditions, it allows for subtle changes.”
The team is working to understand how all the neurons in the ventromedial nucleus co-ordinate their functions to regulate sugar levels during different conditions, including fasting, feeding and stress.
They are also interested in understanding how the brain and nervous system together affect the body’s control of sugar, especially in the liver and pancreas.
Ultra-processed foods (UPFs) have become public enemy number one in nutrition debates. From dementia to obesity and an epidemic of “food addiction”, these factory-made products, including crisps, ready meals, fizzy drinks and packaged snacks, are blamed for a wide range of modern health problems. Some experts argue that they’re “specifically formulated and aggressively marketed to maximise consumption and corporate profits”, hijacking our brain’s reward systems to make us eat beyond our needs.
Policymakers have proposed bold interventions: warning labels, marketing restrictions, taxes, even outright bans near schools. But how much of this urgency is based on solid evidence?
My colleagues and I wanted to step back and ask: what actually makes people like a food? And what drives them to overeat – not just enjoy it, but keep eating after hunger has passed? We studied more than 3,000 UK adults and their responses to over 400 everyday foods. What we found challenges the simplistic UPF narrative and offers a more nuanced way forward.
Two ideas often get blurred in nutrition discourse: liking a food and hedonic overeating (eating for pleasure rather than hunger). Liking is about taste. Hedonic overeating is about continuing to eat because the food feels good. They’re related, but not identical. Many people like porridge but rarely binge on it. Chocolate, biscuits and ice cream, on the other hand, top both lists.
We conducted three large online studies where participants rated photos of unbranded food portions for how much they liked them and how likely they were to overeat them. The foods were recognisable items from a typical UK shopping basket: jacket potatoes, apples, noodles, cottage pie, custard creams – more than 400 in total.
We then compared these responses with three things: the foods’ nutritional content (fat, sugar, fibre, energy density), their classification as ultra-processed by the widely used Nova system – a food classification method that groups foods by the extent and purpose of their processing – and how people perceived them (sweet, fatty, processed, healthy and so on).
Perception power
Some findings were expected: people liked foods they ate often, and calorie-dense foods were more likely to lead to overeating.
But the more surprising insight came from the role of beliefs and perceptions. Nutrient content mattered – people rated high-fat, high-carb foods as more enjoyable, and low-fibre, high-calorie foods as more “bingeable”. But what people believed about the food also mattered, a lot.
Perceiving a food as sweet, fatty or highly processed increased the likelihood of overeating, regardless of its actual nutritional content. Foods believed to be bitter or high in fibre had the opposite effect.
In one survey, we could predict 78% of the variation in people’s likelihood of overeating by combining nutrient data (41%) with beliefs about the food and its sensory qualities (another 38%).
In short: how we think about food affects how we eat it, just as much as what’s actually in it.
This brings us to ultra-processed foods. Despite the intense scrutiny, classifying a food as “ultra-processed” added very little to our predictive models.
Once we accounted for nutrient content and food perceptions, the Nova classification explained less than 2% of the variation in liking and just 4% in overeating.
That’s not to say all UPFs are harmless. Many are high in calories, low in fibre and easy to overconsume. But the UPF label is a blunt instrument. It lumps together sugary soft drinks with fortified cereals, protein bars with vegan meat alternatives.
Some of these products may be less healthy, but others can be helpful – especially for older adults with low appetites, people on restricted diets or those seeking convenient nutrition.
The message that all UPFs are bad oversimplifies the issue. People don’t eat based on food labels alone. They eat based on how a food tastes, how it makes them feel and how it fits with their health, social or emotional goals.
Relying on UPF labels to shape policy could backfire. Warning labels might steer people away from foods that are actually beneficial, like wholegrain cereals, or create confusion about what’s genuinely unhealthy.
Instead, we recommend a more informed, personalised approach:
• Boost food literacy: help people understand what makes food satisfying, what drives cravings, and how to recognise their personal cues for overeating.
• Reformulate with intention: design food products that are enjoyable and filling, rather than relying on bland “diet” options or ultra-palatable snacks.
• Address eating motivations: people eat for many reasons beyond hunger – for comfort, connection and pleasure. Supporting alternative habits while maximising enjoyment could reduce dependence on low-quality foods.
It’s not just about processing
Some UPFs do deserve concern. They’re calorie dense, aggressively marketed and often sold in oversized portions. But they’re not a smoking gun.
Labelling entire categories of food as bad based purely on their processing misses the complexity of eating behaviour. What drives us to eat and overeat is complicated but not beyond understanding. We now have the dataand models to unpack those motivations and support people in building healthier, more satisfying diets.
Ultimately, the nutritional and sensory characteristics of food – and how we perceive them – matter more than whether something came out of a packet. If we want to encourage better eating habits, it’s time to stop demonising food groups and start focusing on the psychology behind our choices.
A comprehensive five-year analysis of gap cover claims reveals a healthcare funding crisis that’s rapidly escalating across the South African private healthcare sector. Data from Sirago Underwriting Managers shows that its mega gap claims – those exceeding R50,000 – have exploded by 512% in volume and 437% in value between 2020 and 2024.
The numbers tell a stark story: where 89 mega gap claims totalling R6.2 million were paid in 2020, this figure rocketed to 549 claims worth R34 million in 2024. Perhaps most concerning is that claims exceeding R60 000 are now daily occurrences, with the average large loss gap claim sitting at R63 000 – a far cry from the R6000 to R12 000 averages seen pre-2020.
The Perfect Storm: Medical Scheme Erosion Meets Provider Cost Inflation
This upward trajectory reflects a fundamental shift in South Africa’s healthcare landscape. Medical schemes – constrained by affordability, access, aging membership populations, and where private healthcare already consumes up to 20% of household income – are systematically reducing benefits and transferring more risk onto the member, rather than increasing premiums to match out-of-control healthcare provider cost inflation.
Healthcare provider costs have consistently outpaced inflation by more than double for years, yet unlike pharmaceuticals, there’s no pricing regulation on healthcare provider tariffs. In a country facing a dire shortage of healthcare professionals, specialists are free to charge rates often 500%+ higher than medical scheme reimbursements.
The regulatory framework compounds this issue. The Registrar of Medical Schemes mandates that for Prescribed Minimum Benefit (PMB) conditions, where no Designated Service Provider agreement exists, healthcare providers must be paid in full regardless of the charge – essentially providing a blank check.
Breaking Down Sirago’s Large Loss (Mega) Gap Claims Data (2020-2024)
Five-Year Trend Analysis
2021: 118% increase in claims value paid compared to 2020, driven by COVID-19 impacts and deferred elective surgeries.
2022-2024: Average annual increase of 35% year-on-year in large loss claims volumes.
Highest claims: R200,000+ for ischaemic heart disease conditions in the 50+ age group.
Age Demographics Challenge Assumptions
Contrary to expectations, healthcare crises aren’t limited to older populations:
50-65 years: 31% of claims (average: R65,065)
66-75 years: 27% of claims (average: R64,213)
76+ years: 18% of claims (average: R62,773)
30-49 years: 18% of claims (average: R58,116)
0-29 years: 5% of claims (average: R63,360)
The under-49 age group constitutes 23% of all large loss claims, dispelling notions that major health expenses only affect older demographics, and which highlights the risk transfer challenges faced and imposed by medical schemes.
Claims Distribution
62%: R40,000-R60,000
30%: R61,000-R100,000
6%: R101,000-R150,000
2%: R151,000-R210,000
Leading Conditions Driving Claims
Musculoskeletal Dominance
Over 51% of claims across all age groups involve musculoskeletal conditions, with spinal stenosis leading the charge. Medical schemes often impose strict limits on elective musculoskeletal surgeries due to high costs, particularly for internal prosthetics where co-payments can reach 30% of the hospital account if members don’t subscribe to the scheme-imposed protocols.
Cancer and Circulatory Conditions
Each representing 10% of large loss claims, these conditions reflect both the effect from the delayed diagnosis impact of COVID-19 and the high-cost nature of specialised treatments. Malignant neoplasms of the breast, prostate, and colon lead cancer claims, while acute ischaemic heart disease dominates circulatory conditions.
The Exploitation Factor
Gap insurance is increasingly becoming a target for exploitation. Healthcare providers now routinely ask patients upfront about gap coverage before determining charges, creating a troubling paradox where a R700 monthly gap policy might pay R130,000 for an orthopaedic surgery shortfall, while the medical scheme with an R8,000 monthly premium pays just R30,000. This exploitation threatens the sustainability of gap insurance itself. If current trends continue, gap insurance premiums will inevitably rise, making this crucial protection unaffordable for many South Africans.
The Critical Importance of Gap Cover
Despite these challenges, gap cover remains essential, irrespective of medical scheme option. Most medical schemes have deductibles, co-payments, and reimbursement limits that can leave members significantly out of pocket. The gap between scheme payments and specialist charges can be substantial – often 200% to 500% above scheme tariffs and this isn’t limited to basic hospital cover options. Even comprehensive, top-tier medical scheme benefits leave members facing substantial tariff shortfalls for in-hospital procedures.
The Economics of Healthcare Financial Protection
When you consider the potential financial quantum of a shortfall on your medical scheme benefits, and that a gap cover premium is around R700 per month for a family (2025 Sirago Ultimate Gap), and each family member is covered for up to a maximum of R213 000 per annum, it is clear that Gap Cover is a non-negotiable part of your healthcare financing strategy. A single gap claim of R63k, Sirago’s average large loss claim, would be the equivalent of almost 9 years of premium payments at current premium rates.
Sirago’s mega claims data reveals a private healthcare funding system under severe strain. As medical schemes transfer more financial risk to members through tariff shortfalls, co-payments, and exclusions, gap insurance becomes not just “a-nice-to-have” insurance policy, but essential for financial protection.
However, the sustainability of this model depends on addressing the root causes: unregulated provider pricing, systematic benefit erosion, and the exploitation of gap insurance by unscrupulous providers. Without intervention, South Africa’s healthcare funding crisis will continue to deepen, leaving patients to bear an ever-increasing financial burden.
For consumers, the message is clear: always negotiate pricing for planned surgeries and request formal quotes from all medical role players. In a system where healthcare providers are price makers and medical schemes and gap providers are price-takers, informed patient advocacy becomes crucial for financial survival and your continued access to quality private healthcare.
(Claims statistics drawn from Sirago’s Large Loss Claims Analysis, 2020-2025)
Sirago Underwriting Managers (Pty) Ltd is an Authorised Financial Services Provider (FSP: 4710) underwritten by GENRIC Insurance Company Limited (FSP: 43638). GENRIC is an authorised Financial Services Provider and licensed non-life Insurer and a member of the Old Mutual Group.
Note: The content of this article does not constitute financial advice. Sirago Gap cover is subject to terms and conditions and premiums are reviewed annually. For more information go to www.sirago.co.za (Ts & Cs apply).
Weight-loss interventions, including gastric bypass surgery and drugs that prevent dietary fat absorption, can be invasive or have negative side effects. Now, researchers have developed edible microbeads made from green tea polyphenols, vitamin E and seaweed that, when consumed, bind to fats in the gastrointestinal tract. Preliminary results from tests with rats fed high-fat diets show that this approach to weight loss may be safer and more accessible than surgery or pharmaceuticals.
Yue Wu, a graduate student at Sichuan University, will present her team’s results at the ACS Fall 2025 Digital Meeting, a meeting of the American Chemical Society.
“Losing weight can help some people prevent long-term health issues like diabetes and heart disease,” says Wu. “Our microbeads work directly in the gut to block fat absorption in a noninvasive and gentle way.”
Weight gain is caused by genetic and lifestyle factors, including eating a high-fat diet. A high-fat diet is defined by the U.S. Department of Agriculture as one where 35% or more of a person’s daily calories come from fat, as opposed to protein or carbohydrates. Some pharmaceuticals, such as orlistat, inhibit certain gastric enzymes from breaking down dietary fats, leading to less fat being absorbed by the body. Orlistat is a U.S. Food and Drug Administration (FDA)-approved medication and is effective for weight loss. However, for some people it causes serious side effects, including liver and kidney damage.
So, Wu and her colleagues wanted to target the fat absorption process with their weight-loss intervention but do so without negative side effects. “We want to develop something that works with how people normally eat and live,” says Wu.
To get started, the team created tiny plant-based beads that spontaneously form through a series of chemical bonds between the green tea polyphenols and vitamin E. These structures can form chemical tethers to fat droplets and serve as the fat-binding core of the microbeads. The researchers then coated the spheres in a natural polymer derived from seaweed to protect them from the acidic environment of the stomach. Once ingested, the protective polymer coating expands in response to the acidic pH, and the green tea polyphenols and vitamin E compounds bind to and trap partially digested fats in the intestine.
The microbeads are nearly flavourless, and the researchers foresee them being easily integrated into people’s diets. For example, the microbeads could be made into small tapioca- or boba-sized balls and added to desserts and bubble teas.
The researchers assessed the microbeads as a weight-loss treatment in rats. They put the animals into three groups (eight rats per group), those which were fed a high-fat diet (60% fats) either with or without microbeads and those which were fed a normal diet (10% fats) for 30 days. Rats fed the high-fat diet and microbeads:
Lost 17% of their total body weight, while rats in the other groups didn’t lose weight.
Had reduced adipose tissue and less liver damage compared to rats fed the high-fat and normal diets without microbeads.
Excreted more fat in their feces compared to rats not given microbeads. The extra fat in the rats’ feces had no apparent ill effects on the animals’ health.
Additionally, the eight rats on high-fat diets that consumed microbeads showed similar intestinal fat excretion, but without the gastrointestinal side effects the researchers observed with a fourth group of rats they treated with orlistat.
Wu and her team have started working with a biotechnology company to manufacture the plant-based beads. “All the ingredients are food grade and FDA-approved, and their production can be easily scaled up,” says Yunxiang He, Sichuan University associate professor and co-author on Wu’s presentation.
They’ve also initiated a human clinical trial in collaboration with the West China Hospital of Sichuan University. “This represents a major step toward clinical translation of our polyphenol-based microbeads, following our foundational results,” says Wu. “We have officially enrolled 26 participants in our investigator-initiated trial, and we anticipate that preliminary data may become available within the next year.”
People recovering from heart failure should consider improving the regularity of their sleep, a study led by Oregon Health & Science University suggests. The research team found that even moderately irregular sleep doubles the risk of having another clinical event within six months, according to a study published in the journal JACC Advances. A clinical event could be another visit to the emergency room, hospitalisation or even death.
“Going to bed and waking up at consistent times is important for overall health,” said lead author Brooke Shafer, PhD, a research assistant professor in the Sleep, Chronobiology and Health Laboratory in the OHSU School of Nursing. “Our study suggests that consistency in sleep timing may be especially important for adults with heart failure.”
Researchers enrolled 32 patients who had been hospitalised for acutely decompensated heart failure at OHSU Hospital and Hillsboro Medical Center from September 2022 through October 2023. For one week following hospital discharge, participants used sleep diaries to record the time they fell asleep at night, woke up in the morning and the timing of naps they took during the day.
The participants were then categorised as regular sleepers or moderately irregular sleepers, based on their sleep patterns.
The study found:
Following discharge from the hospital, 21 participants experienced a clinical event over the course of six months.
Of that group, 13 were classified as moderately irregular sleepers compared with eight classified as having a regular sleep schedule.
Statistically, the irregular sleepers had more than double the risk of an event across the six-month time span.
The increased risk of a clinical event for moderately irregular sleepers remained even when accounting for possible contributing factors like sleep disorders and other underlying medical conditions. The research team says the study is among the first to examine the impact of sleep regularity in the context of heart failure, and the findings add to a growing body of evidence suggesting the importance of maintaining a regular sleep schedule.
“Improving sleep regularity may be a low-cost therapeutic approach to mitigate adverse events in adults with heart failure,” the authors conclude.
Shafer said the results strengthen the connection between sleep regularity and cardiovascular health.
“When we’re asleep and in a resting state, our blood pressure and heart rate decrease compared with daytime levels,” she said. “But variability in sleep timing may disrupt mechanisms involved in the regulation of the cardiovascular system. Irregular sleep may contribute to adverse outcomes, especially for people already affected by heart failure.”
The next step would be to scale up the research to a larger cohort of participants and see whether improving sleep regularity lowers the risk of another clinical event, she said.
A new study from Pitt researchers challenges a decades-old assumption in neuroscience by showing that the brain uses distinct transmission sites – not a shared site – to achieve different types of plasticity. The findings, published in Science Advances, offer a deeper understanding of how the brain balances stability with flexibility, a process essential for learning, memory and mental health.
Neurons communicate through a process called synaptic transmission, where one neuron releases chemical messengers called neurotransmitters from a presynaptic terminal. These molecules travel across a microscopic gap called a synaptic cleft and bind to receptors on a neighbouring postsynaptic neuron, triggering a response.
Traditionally, scientists believed spontaneous transmissions (signals that occur randomly) and evoked transmissions (signals triggered by sensory input or experience) originated from one type of canonical synaptic site and relied on shared molecular machinery. Using a mouse model, the research team, led by Oliver Schlüter, associate professor of neuroscience, discovered that the brain instead uses separate synaptic transmission sites to carry out regulation of these two types of activity, each with its own developmental timeline and regulatory rules.
“We focused on the primary visual cortex, where cortical visual processing begins,” said Yue Yang, a research associate in the Department of Neuroscience and first author of the study. “We expected spontaneous and evoked transmissions to follow a similar developmental trajectory, but instead, we found that they diverged after eye opening.”
As the brain began receiving visual input, evoked transmissions continued to strengthen. In contrast, spontaneous transmissions plateaued, suggesting that the brain applies different forms of control to the two signaling modes.
To understand why, the researchers applied a chemical that activates otherwise silent receptors on the postsynaptic side. This caused spontaneous activity to increase, while evoked signals remained unchanged – strong evidence that the two types of transmission operate through functionally distinct synaptic sites.
This division likely enables the brain to maintain consistent background activity through spontaneous signaling while refining behaviourally relevant pathways through evoked activity. This dual system supports both homeostasis and Hebbian plasticity, the experience-dependent process that strengthens neural connections during learning.
“Our findings reveal a key organizational strategy in the brain,” said Yang. “By separating these two signaling modes, the brain can remain stable while still being flexible enough to adapt and learn.”
The implications could be broad. Abnormalities in synaptic signaling have been linked to conditions like autism, Alzheimer’s disease and substance use disorders. A better understanding of how these systems operate in the healthy brain may help researchers identify how they become disrupted in disease.
“Learning how the brain normally separates and regulates different types of signals brings us closer to understanding what might be going wrong in neurological and psychiatric conditions,” Yang said.
Researchers at the Leibniz Institute for Plasma Science and Technology (INP) have collaborated with partners at Greifswald University Hospital and University Medical Centre Rostock to demonstrate that cold plasma can effectively combat tumour cells even in deeper tissue layers. What is particularly noteworthy is that, by developing new tissue models, they were able to precisely investigate the effect of individual plasma components on tumour cells for the first time.
Plasma is an ionised gas that produces a large number of chemically reactive molecules known as reactive oxygen and nitrogen species. These short-lived molecules can have a strong influence on biological processes such as the growth or death of tumour cells.
New tissue models provide important insights
“The effect of plasma in tissue is very complex and little understood. We have therefore developed a 3D model made of hydrogels that mimics real tumour tissue. In this model, we were able to observe exactly how deep the molecules from the plasma penetrate – and which of these molecules are important for the effect on tumour cells,” explains Lea Miebach, first author of the study. Particularly short-lived molecules such as peroxynitrite penetrated several millimetres deep into the tissue. Hydrogen peroxide, which had previously been considered the main active ingredient in laboratory research, showed little effect: even when it was specifically removed, the effect of the plasma remained strong.
Use during surgery also conceivable
Another model investigated how well plasma could work in the follow-up treatment of tumour surgery. Residual tumour cells at the edge of an artificial surgical wound were specifically treated with plasma. The result: here too, a strong effect was observed, especially in cells that had already spread into the surrounding tissue. These findings could help to better prevent relapses after surgery.
Important step for plasma medicine
“Our results could significantly improve the medical application of plasma,” says Prof Dr Sander Bekeschus, head of the Plasma Medicine research programme at INP. “The better we understand which molecules are active in the tissue, the more precisely plasma devices can be used for specific types of cancer.”
The work was carried out using the medically approved plasma jet “kINPen”. In the long term, the method could help make therapies more effective and gentler.
People who have had COVID are at increased risk of developing certain inflammatory diseases of the airways, such as asthma, hay fever and chronic sinusitis. However, vaccination against the SARS-CoV-2 virus appears to reduce the risk, according to a comprehensive epidemiological study led by researchers at Karolinska Institutet.
The international research team used an electronic health database in the United States, TriNetX, to investigate the link between COVID and so-called type-2 inflammatory diseases, a group of chronic conditions in which the immune system overreacts to allergens or infections.
The researchers compared 973 794 people who had had COVID with 691 270 people who had been vaccinated against the SARS-CoV-2 virus and 4 388 409 healthy controls with no documented infection or vaccination.
Inflammation in the airways
The results are presented in The Journal of Allergy and Clinical Immunology. People who had had COVID had a 66% higher risk of developing asthma, a 74% higher risk of chronic sinusitis and a 27% higher risk of hay fever compared with healthy controls. However, no increased risk was seen for the skin disease atopic eczema or for eosinophilic oesophagitis, an inflammation of the oesophagus.
“Our results suggest that COVID-19 can trigger type-2 inflammation in the airways, but not in other organs,” says Philip Curman, a physician and researcher at the Department of Medical Epidemiology and Biostatistics at Karolinska Institutet, Sweden, who led the research.
Vaccination against the virus had the opposite effect. The risk of asthma was 32% lower among vaccinated individuals compared with healthy unvaccinated individuals. The risk of sinusitis and hay fever was also slightly lower.
More than twice the risk
When people who had had COVID were compared with vaccinated individuals, an even clearer effect was seen. Infected individuals had more than twice the risk of developing asthma or chronic sinusitis and a 40% higher risk of developing hay fever compared with those who had been vaccinated.
“It is interesting to see that vaccination not only protects against the infection itself, but also appears to provide good protection against certain respiratory complications,” says Philip Curman.
The study is retrospective, i.e. based on data that has already been collected. This means that the researchers cannot draw any firm conclusions about causal links. Another limitation is that some infections may have gone undiagnosed, especially if they were detected through self-testing.
The research was conducted in close collaboration with the University of Lübeck and the Lübeck Institute of Experimental Dermatology in Germany, the Technical University of Madrid in Spain and Bar-Ilan University in Israel. It was mainly funded by the German Research Foundation (Deutsche Forschungsgemeinschaft), Region Stockholm and Karolinska Institutet. Two researchers received travel grants from TriNetX, which provides the database used in the study, and one of the authors is employed by the company.
Researchers at the Icahn School of Medicine at Mount Sinai have found that prenatal exposure to paracetamol may increase the risk of neurodevelopmental disorders, including autism spectrum disorder and attention-deficit/hyperactivity disorder (ADHD), in children. The study, published in BMC Environmental Health, is the first to apply the rigorous Navigation Guide methodology to systematically evaluate the rigour and quality of the scientific literature.
Paracetamol (known as acetaminophen in the US and Canada) is the most commonly used over-the-counter pain and fever medication during pregnancy and is used by more than half of pregnant women worldwide. Until now, acetaminophen has been considered the safest option for managing headache, fever, and other pain. Analysis by the Mount Sinai-led team of 46 studies incorporating data from more than 100 000 participants across multiple countries challenges this perception and underscores the need for both caution and further study.
The Navigation Guide Systematic Review methodology is a gold-standard framework for synthesising and evaluating environmental health data. This approach allows researchers to assess and rate each study’s risk of bias, such as selective reporting of the outcomes or incomplete data, as well as the strength of the evidence and the quality of the studies individually and collectively.
“Our findings show that higher-quality studies are more likely to show a link between prenatal acetaminophen exposure and increased risks of autism and ADHD,” said Diddier Prada, MD, PhD, Assistant Professor of Population Health Science and Policy, and Environmental Medicine and Climate Science, at the Icahn School of Medicine at Mount Sinai. “Given the widespread use of this medication, even a small increase in risk could have major public health implications.”
The paper also explores biological mechanisms that could explain the association between acetaminophen use and these disorders. Paracetamol is known to cross the placental barrier and may trigger oxidative stress, disrupt hormones, and cause epigenetic changes that interfere with foetal brain development.
While the study does not show that paracetamol directly causes neurodevelopmental disorders, the research team’s findings strengthen the evidence for a connection and raise concerns about current clinical practices.
The researchers call for cautious, time-limited use of paracetamol during pregnancy under medical supervision; updated clinical guidelines to better balance the benefits and risks; and further research to confirm these findings and identify safer alternatives for managing pain and fever in expectant mothers.
“Pregnant women should not stop taking medication without consulting their doctors,” Dr Prada emphasised. “Untreated pain or fever can also harm the baby. Our study highlights the importance of discussing the safest approach with health care providers and considering non-drug options whenever possible.”
With diagnoses of autism and ADHD increasing worldwide, these findings have significant implications for public health policy, clinical guidelines, and patient education. The study also highlights the urgent need for pharmaceutical innovation to provide safer alternatives for pregnant women.
