Scientists uncover cancer-causing chemicals hidden in everyday foods

 More people are paying close attention to what they eat, often tracking calories, exercising daily, and filling their plates with foods that seem naturally healthy, including fruits and vegetables. Yet even nutritious foods can carry hidden chemical concerns. Some contaminants can enter food from the environment, while others can form during high heat cooking methods such as heating, smoking, grilling, roasting, and frying.

Among the compounds of concern are polycyclic aromatic hydrocarbons, or PAHs (hydrophobic organic compounds comprising multiple fused aromatic rings). Some PAHs are known for their cancer causing potential, which makes reliable food testing an important part of protecting public health.

A Hidden Food Safety Challenge

Detecting PAHs in food is not simple. Conventional extraction methods, such as solid phase extraction, liquid liquid extraction, and accelerated solvent extraction, can be affordable, but they often require lengthy preparation, heavy hands on labor, and chemical intensive procedures that are not ideal for workers or the environment.

To solve these problems, scientists have been turning to a streamlined method known as QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe). The approach is designed to speed up sample preparation, reduce chemical use, improve recovery rates, and make food contaminant testing more practical for routine safety checks.

In a 2025 study, researchers from the Department of Food Science and Biotechnology at Seoul National University of Science and Technology, led by Professor Joon-Goo Lee, used QuEChERS to measure eight PAHs (Benzo[a]anthracene, Chrysene, Benzo[b]fluoranthene, Benzo[k]fluoranthene, Benzo[a]pyrene, Indeno[1,2,3-cd]pyrene, Dibenz[a,h]anthracene, and Benzo[g,h,i]perylene in food. The findings were published in the journal Food Science and Biotechnology.

Faster Testing With Strong Accuracy

The team used acetonitrile to extract PAHs from food samples, then tested several purification strategies involving different combinations of sorbents. The method was validated across multiple food matrices, showing strong performance. Calibration curves for all eight PAHs had R2 values above 0.99, indicating a highly linear and reliable measurement system.

Further analysis using gas chromatography and mass spectrometry showed that the limits of detection ranged from 0.006 to 0.035 µg/kg, while the limits of quantification ranged from 0.019 to 0.133 µg/kg. Recovery rates were also strong, ranging from 86.3 to 109.6% at 5 µg/kg, 87.7 to 100.1% at 10 µg/kg, and 89.6 to 102.9% at 20 µg/kg. Precision values stayed between 0.4 and 6.9% across all tested food matrices.

The study also reported that, among the foods tested, the highest PAH levels were found in soybean oil, followed by duck meat and canola oil.

Prof. Lee explains, "This method not only simplifies the analytical process but also demonstrates high efficiency in detection compared to conventional methods. It can be applied to a wide range of food matrices."

Why PAHs Matter

PAHs can form when food is exposed to high temperatures or smoke. According to the National Cancer Institute, PAHs can develop when fat and juices from meat drip onto a hot surface or open flame, creating smoke that deposits these compounds onto the food. PAHs can also form during smoking and may be found in sources such as cigarette smoke and car exhaust fumes.

The NCI notes that PAHs and related high temperature cooking compounds have caused cancer in animal studies, although human population studies have not established a definitive link between exposure from cooked meats and cancer. This uncertainty is one reason more accurate measurement tools are valuable. Better testing can help regulators, researchers, and food companies understand where contamination is occurring and how it can be reduced.

Newer Research Points to Broader Use

Since the SeoulTech study, other researchers have continued refining QuEChERS based methods for PAH detection. A 2025 study in Foods developed a modified QuEChERS method with a freeze out step and applied it to 302 retail food samples. That work found the highest concentration of four priority PAHs in Kezuribushi, a smoked and dried fish product, and identified grilled chicken feet as a possible health concern based on the European Food Safety Authority margin of exposure approach.

Another 2025 study focused on cereals and cereal based products. Researchers developed a modified QuEChERS method using Z Sep⁺ clean up and gas chromatography with tandem mass spectrometry. In 96 cereal samples and 18 cereal based products from the Romanian market, only chrysene was quantified in 17% of cereal samples, while no PAHs were quantified in the derived products.

Source: ScienceDaily

A silent kidney crisis is spreading far faster than experts expected

 Chronic kidney disease has become one of the world's most widespread and deadly health problems, with record numbers of people now estimated to have reduced kidney function.

A 2025 global analysis found that the number of people living with the condition rose from 378 million in 1990 to 788 million in 2023. As the global population has grown and aged, chronic kidney disease has moved into the top 10 causes of death worldwide for the first time.

The work was led by researchers at NYU Langone Health, the University of Glasgow, and the Institute for Health Metrics and Evaluation (IHME) at the University of Washington. It examined the growing toll of a disease that slowly weakens the kidneys' ability to remove waste and extra fluid from the blood.

In mild cases, people may feel no symptoms at all. In advanced cases, patients may need dialysis, kidney replacement therapy, or a kidney transplant.

A Disease Many People Never See Coming

The analysis estimated that about 14% of adults worldwide have chronic kidney disease. It also found that roughly 1.5 million people died from the condition in 2023. After adjusting for differences in age patterns across countries, deaths were more than 6% higher than in 1993.

"Our work shows that chronic kidney disease is common, deadly, and getting worse as a major public health issue," said study co-senior author Josef Coresh, MD, PhD, director of NYU Langone's Optimal Aging Institute. "These findings support efforts to recognize the condition alongside cancer, heart disease, and mental health concerns as a major priority for policymakers around the world."

In May 2025, the World Health Organization formally placed chronic kidney disease on its agenda for reducing early deaths from noncommunicable diseases by one third before 2030. Coresh said that tackling the problem requires a clear and current picture of how the disease is affecting populations around the world. He is also the Terry and Mel Karmazin Professor of Population Health at the NYU Grossman School of Medicine.

The report was published in The Lancet and was also presented at the American Society of Nephrology's annual Kidney Week conference. According to the authors, it was the most comprehensive global estimate of chronic kidney disease in nearly a decade.

A Global Snapshot of Kidney Damage

The investigation was part of the Global Burden of Disease (GBD) 2023 study, a large international effort to track health loss across countries and over time. Its results are often used to guide public health policy and shape global health research priorities.

For the analysis, researchers reviewed 2,230 published research papers and national health datasets from 133 countries. They looked at patterns in diagnoses and deaths, and also measured how much disability is linked to chronic kidney disease.

The findings showed that kidney damage does not only threaten the kidneys. Impaired kidney function was also a major risk factor for heart disease, contributing to about 12% of global cardiovascular deaths.

In 2023, chronic kidney disease was also the 12th leading cause of reduced quality of life from disability. The biggest risk factors were high blood sugar, high blood pressure, and high body mass index (a measure of obesity).

Early Treatment Could Change the Trajectory

Most people with chronic kidney disease in the study were still in the early stages. That detail matters because earlier action can often slow the disease and help patients avoid more intensive and costly treatments later.

Coresh said medications and lifestyle changes can help prevent progression to dialysis or kidney transplantation when the condition is caught early enough.

Access to treatment, however, is uneven. In sub-Saharan Africa, Southeast Asia, Latin America, and other low-income regions, relatively few people receive dialysis or kidney transplants. The likely reason is that these treatments are often less available and harder to afford in those areas.

"Chronic kidney disease is underdiagnosed and undertreated," said study co-lead author Morgan Grams, MD, PhD. "Our report underscores the need for more urine testing to catch it early and the need to ensure that patients can afford and access therapy once they are diagnosed."

Grams, the Susan and Morris Mark Professor of Medicine at the NYU Grossman School of Medicine, said several medications introduced over the past five years can slow kidney disease and lower the risk of heart attack, stroke, and heart failure. Still, she noted that it will take time for those advances to improve outcomes on a global scale.

Source: ScienceDaily

Intermittent fasting triggers surprising changes in the brain

 More than one billion people worldwide now live with obesity, a condition that raises the risk of cardiovascular disease, diabetes, and several types of cancer. Yet losing weight and keeping it off can be extremely difficult. The body does not simply respond to fewer calories in a straightforward way. Signals from the gut, hormones, metabolism, and the brain can all influence hunger, cravings, and weight regain.

One approach that has drawn growing interest is intermittent energy restriction (IER), a form of dieting in which periods of reduced calorie intake are followed by periods of more typical eating. Research published in 2023 suggests that this strategy may do more than reduce body weight. It may also shift the relationship between gut bacteria and brain activity in ways that are closely tied to appetite and food behavior.

"Here we show that an IER diet changes the human brain-gut-microbiome axis. The observed changes in the gut microbiome and in the activity in addition-related brain regions during and after weight loss are highly dynamic and coupled over time," said last author Dr. Qiang Zeng, a researcher at the Health Management Institute of the PLA General Hospital in Beijing.

Intermittent fasting and the brain

To explore what happens inside the body during weight loss, the researchers studied 25 adults with obesity in China. The volunteers, who were about 27 years old on average, had a BMI between 28 and 45.

The team used several tools to track changes over time. Stool samples were analyzed with metagenomics to measure the composition of the gut microbiome. Blood tests were used to monitor metabolic and physiological changes. The researchers also used functional magnetic resonance imaging (fMRI) to examine activity in brain regions involved in appetite, emotion, attention, learning, inhibition, and reward.

"A healthy, balanced gut microbiome is critical for energy homeostasis and maintaining normal weight. In contrast, an abnormal gut microbiome can change our eating behavior by affecting certain brain area involved in addiction," explained coauthor Dr. Yongli Li from the Department of Health Management of Henan Provincial People's Hospital in Henan, China.

A carefully controlled weight loss program

The study began with a 32 day high controlled fasting phase. During this period, participants received meals designed by a dietitian. Their calorie intake was gradually reduced in steps until it reached about one quarter of their basic energy needs.

This was followed by a 30 day low controlled fasting phase. During this stage, participants were given a list of recommended foods rather than fully prepared meals. Those who followed the plan exactly would consume 500 calories per day for women and 600 calories per day for men.

By the end of the intervention, participants had lost an average of 7.6 kilograms, equal to about 7.8% of their starting body weight. They also had reductions in body fat and waist circumference.

The metabolic improvements extended beyond weight. Blood pressure fell, as did fasting plasma glucose, total cholesterol, HDL, LDL, and the activity of key liver enzymes. According to the researchers, these changes suggest that intermittent energy restriction may help reduce obesity related problems such as hypertension, hyperlipidemia, and liver dysfunction.

Brain and gut changes moved together

The researchers found that the weight loss program was linked to lower activity in several brain regions involved in appetite and addiction related behavior. These changes may help explain why dieting affects not only body size, but also food cravings, self control, and the drive to eat.

At the same time, the gut microbiome shifted. The abundance of Faecalibacterium prausnitzii, Parabacteroides distasonis, and Bacterokles uniformis rose sharply. Escherichia coli decreased.

Further analysis suggested that certain microbes were connected with activity in specific brain areas. The abundance of E. coli, Coprococcus comes, and Eubacterium hallii was negatively associated with activity in the brain's left orbital inferior frontal gyrus, a region involved in executive function and willpower during weight loss.

Other bacteria showed the opposite pattern. P. distasonis and Flavonifractor plautii were positively linked with brain regions involved in attention, motor inhibition, emotion, and learning.

These findings point to a striking possibility: as people lose weight, the gut microbiome and the brain may change together. The study cannot prove whether gut bacteria drive the brain changes, whether the brain drives microbial changes, or whether another factor influences both. Still, the results add to evidence that weight control is not just a matter of willpower or calories. It may involve a changing biological conversation between the gut and the brain.

Source: ScienceDaily

The forgotten organ that could predict how long you live

 Researchers at Mass General Brigham have uncovered evidence that the thymus, a small immune system organ long thought to lose its importance after childhood, may play a major role in adult health. Two new studies found that adults with healthier thymuses were more likely to live longer and less likely to develop serious diseases. The research also suggests that thymic health may influence how well cancer patients respond to immunotherapy.

The findings were published in two papers in the same issue of Nature and challenge decades of assumptions about the thymus. The results indicate that the organ remains important throughout adulthood and could eventually help guide disease prevention strategies and cancer treatment decisions.

"The thymus has been overlooked for decades and may be a missing piece in explaining why people age differently, and why cancer treatments fail in some patients," said Hugo Aerts, PhD, corresponding author on the papers and director of the Artificial Intelligence in Medicine (AIM) Program at Mass General Brigham. "Our findings suggest thymic health deserves much more attention and may open new avenues for understanding how to protect the immune system as we age."

What the Thymus Does

Located in the chest, the thymus helps train T cells, a type of immune cell that helps defend the body against infections and disease. Because the organ gradually shrinks after puberty and produces fewer new T cells over time, many scientists assumed it played only a limited role in adult health.

As a result, the thymus has received relatively little attention in large population studies. Earlier research connected T cell diversity to aging and declining immune function, but those studies were typically small and focused on blood samples.

The new research took a much broader approach. Investigators analyzed data from more than 25,000 adults participating in a national lung cancer screening trial, along with more than 2,500 people enrolled in the Framingham Heart Study, a long-running study that tracks the health of generally healthy adults.

AI Reveals Links to Longevity and Disease Risk

Using artificial intelligence (AI) to evaluate routine CT scans, the researchers measured the size, structure, and composition of the thymus. From those measurements, they created a "thymic health" score.

People with higher thymic health scores experienced significantly better outcomes. Compared with individuals who had poorer thymic health, they had about a 50% lower risk of death from any cause, a 63% lower risk of death from cardiovascular disease, and a 36% lower risk of developing lung cancer. These relationships remained strong even after accounting for age and other health factors.

The researchers believe that declines in thymic health may reduce T cell diversity, making it harder for the immune system to recognize and respond to new threats such as cancer and other diseases.

Their analysis also identified several factors associated with poorer thymic health, including chronic inflammation, smoking, and higher body weight. These findings suggest that lifestyle factors and ongoing inflammation may affect the immune system's ability to remain resilient over time.

Thymus Health and Cancer Immunotherapy

In a separate study, the team examined CT scans and clinical outcomes from more than 1,200 cancer patients treated with immunotherapy.

The results showed that patients with healthier thymuses tended to respond better to treatment. They faced about a 37% lower risk of cancer progression and a 44% lower risk of death, even after researchers adjusted for differences in patients, tumors, and treatment approaches.

According to the researchers, these findings highlight a potentially important but previously underrecognized role for the thymus in determining how effectively modern cancer immunotherapies work.

More Research Needed

The scientists emphasize that additional studies will be needed to confirm the results. They also note that the imaging technique used to measure thymic health is not yet ready for routine use in clinical practice.

Although lifestyle factors were associated with thymic health, the studies did not investigate whether changing those factors can directly improve thymus function.

The research team is continuing to explore other influences on thymic health. One ongoing study is examining whether unintended radiation exposure to the thymus during lung cancer treatment could affect patient outcomes.

"Improving our understanding and monitoring of thymic health could eventually help physicians better assess disease risk and guide treatment decisions," said Aerts.

Source: ScienceDaily

Your brain starts making social decisions before you do

 Why do we decide to approach other people? According to new research from the Hebrew University of Jerusalem, the answer may begin unfolding in the brain several seconds before any movement takes place.

The study found that social behavior is preceded by a distinctive pattern of activity that spreads across the brain. Researchers also discovered that the strength of this neural pattern is linked to how socially motivated an individual is.

The work was led by Dr. Lilah Avitan and carried out by PhD student Imri Lifshitz and other members of Avitan's laboratory at the Edmond and Lily Safra Center for Brain Sciences (ELSC) at the Hebrew University of Jerusalem.

Tracking Social Decisions in Real Time

To investigate how the brain turns social information into action, the researchers used zebrafish, a model organism that allows scientists to monitor brain activity at the level of individual cells.

The team created a new experimental system in which one fish watched and responded to another fish that was swimming nearby. While this happened, researchers recorded activity throughout the observer fish's entire brain in real time.

This setup allowed them to examine the neural events leading up to a social decision and follow the process as it unfolded moment by moment.

A Brain-Wide Signal Appears Before Social Behavior

The researchers found that when a fish was about to swim toward another fish, changes in brain activity began several seconds before the movement itself.

Instead of relying on a single brain region dedicated to social behavior, the process involved coordinated changes across multiple parts of the brain.

Activity increased in the pallium, a higher brain region associated with complex behaviors. At the same time, activity decreased in other brain areas.

Together, these changes created what researchers describe as a neural "pre-decision state." This brain-wide pattern signaled that a social action was about to occur and could be used to predict the behavior before it happened.

Brain Activity Linked to Social Drive

The study also revealed that the strength of this neural signature varied among individuals.

Fish that showed a stronger brain-wide pattern tended to be more social overall, suggesting that the neural signal reflects an individual's underlying social drive.

The findings further highlighted the importance of the pallium. Results suggest that this brain region plays a central role in generating the motivation to approach others and engage in social interactions.

"This study identifies a brain-wide neural signature of social approach that emerges before movement begins," said Dr. Avitan. "This signature predicts not only whether an upcoming action will be social, but also how strongly socially driven the individual is."

What the Findings Could Mean

Understanding how the brain generates social behavior may help researchers better explain why some individuals are naturally more social than others.

Because similar brain structures contribute to social behavior across many species, the findings could also offer clues about human social function and conditions in which social behavior is altered or disrupted.

Source: ScienceDaily

A single protein may be holding back CAR T cancer therapy

 Researchers from Columbia University and University Hospital Tübingen have discovered a protein that appears to play a major role in weakening CAR T cells over time. By disabling the protein, known as NFIL3, the scientists found that these engineered immune cells remained active longer and were better able to attack tumors. The findings, published in Cancer Discovery, could help improve CAR T-cell therapy, particularly against solid tumors that have proven difficult to treat.

CAR T-cell therapy is one of the most advanced forms of personalized cancer treatment. The approach involves collecting a patient's own immune cells, genetically modifying them to recognize cancer, and then returning them to the body to seek out and destroy tumor cells.

The therapy has produced remarkable results for some blood cancers. However, it has been far less successful against solid tumors. An international team led by Prof. Michel Sadelain, MD, PhD, of Columbia University, working with Prof. Judith Feucht, MD, of University Hospital Tübingen, set out to better understand why. Sadelain is widely recognized as one of the pioneers of CAR T-cell therapy and has played a key role in its development and clinical use.

NFIL3 Linked to CAR T-Cell Exhaustion

To identify factors that limit CAR T-cell performance, the researchers conducted a large-scale analysis of roughly 400 transcription factors, proteins that control which genes are switched on or off inside cells.

Their investigation pointed to NFIL3 as a major contributor to CAR T-cell exhaustion, a process in which the cells gradually lose their ability to function effectively. When the researchers removed NFIL3, the CAR T cells stayed active for longer periods, multiplied more efficiently, and maintained stronger anti-tumor effects.

The team used CRISPR/Cas9 gene-editing technology to disable the gene responsible for producing NFIL3. Often described as genetic scissors, CRISPR allows scientists to precisely cut and modify DNA.

"Switching off NFIL3 could be a decisive step toward significantly improving the long-term potency of CAR T cells," explains Prof. Feucht.

Stronger Tumor Control in Animal Studies

The benefits of removing NFIL3 were demonstrated across several mouse models. CAR T cells lacking the protein were more effective at controlling tumors and helped extend survival.

The results suggest a possible path toward improving treatment for cancers that currently respond poorly to CAR T-cell therapy, particularly solid tumors.

"Our goal is to improve the effectiveness of CAR T cells in solid tumors as well," says Celina May, co-first author of the study and a member of Prof. Feucht's research group. "We expect this to open up new possibilities in the treatment of cancer patients," adds Feucht.

Bridging Laboratory Research and Patient Care

Prof. Feucht combines cancer research with hands-on clinical care. She conducts research within Germany's only Cluster of Excellence in oncology, iFIT (Image Guided and Functionally Instructed Tumor Therapies), while also treating children and adolescents at the Department of Pediatrics at University Hospital Tübingen.

Her work follows the "bench-to-bedside" approach, which focuses on translating scientific discoveries into treatments that can directly benefit patients. Although additional research will be needed before this strategy can be tested and used in people, the findings provide encouraging evidence that targeting NFIL3 could strengthen CAR T-cell therapy and potentially expand its usefulness against a wider range of cancers.

Source: ScienceDaily

The secret to pigeons’ incredible navigation was hiding in their liver

 How pigeons can travel hundreds of miles and still find their way home has puzzled scientists for decades. New research suggests the answer may lie in an unexpected place: the liver.

According to a study published in Science, pigeons may use specialized immune cells in their livers to detect Earth's magnetic field, providing them with an internal navigation system.

Researchers found that these cells, called macrophages, accumulate iron while breaking down old red blood cells. The iron gives the cells unique magnetic properties that could allow them to respond to the planet's magnetic field. When the cells were removed, pigeons struggled to find their way home, pointing to a previously unknown role in navigation.

"We didn't expect immune cells to act like sensors for magnetic fields at all. Our results reveal a previously unknown mechanism for magnetic perception in animals," says Prof. Christian Kurts, Director at the Institute of Molecular Medicine and Experimental Immunology at the University Hospital Bonn, and one of the study's co-senior authors.

"What looks like a 'gut feeling' in bird navigation may actually have a physical basis," adds Prof. Martin Wikelski, Director at the Max Planck Institute of Animal Behavior and the other co-senior author of the study.

The Long Search for Birds' Magnetic Sense

Scientists have long known that homing pigeons and migratory birds use Earth's magnetic field as one of several tools for navigation. However, exactly how animals detect that field has remained one of biology's biggest mysteries.

Over the years, researchers proposed several possibilities. Some theories suggested birds could detect magnetic fields through light-sensitive molecules in their eyes. Others pointed to tiny magnetic particles in their beaks. Despite years of investigation, neither idea has received strong experimental confirmation.

The new study offers a different explanation, combining expertise from immunology, physics, and animal behavior. The research team included scientists from the University of Bonn, the University Hospital Bonn, the University of Duisburg-Essen, and the Max Planck Institute of Animal Behavior (MPI-AB).

Iron-Rich Liver Cells Show Strong Magnetic Properties

To determine where magnetic sensing might occur, the researchers examined multiple organs that have previously been linked to magnetoreception, including the eyes, beak, and brain. They also analyzed the liver and spleen using techniques known as "vibrating sample magnetometry" and "magnetic cell separation."

"We had some clues that the liver and spleen have magnetic properties, because they break down red blood cells and so store much iron in the body," says first author Dr. Clivia Lisowski, from the University of Bonn and the University Hospital Bonn, who led the immunological work.

The results were striking. Among all the tissues studied, the liver contained the highest concentration of iron and produced the strongest magnetic response.

"Iron is crystallized in oxide nanoparticles making the cells superparamagnetic and reactive to magnetic fields. We found by far the strongest magnetic response in liver tissue," adds Prof. Ulf Wiedwald, from the University of Duisburg-Essen.

Further investigation revealed that liver macrophages were responsible for these magnetic properties.

Navigation Experiments Reveal a Critical Role

The researchers then tested whether the macrophages actually influence navigation.

At the MPI-AB in Konstanz, Germany, pigeons had been trained to return to their aviary from locations more than twenty kilometers away. Scientists removed the liver macrophages and monitored how the birds performed.

The results depended on the weather. On overcast days, when the sun was hidden, pigeons that lacked the macrophages lost their sense of direction and had difficulty navigating home. On sunny days, however, they successfully returned, likely relying on the sun as a navigational cue instead of Earth's magnetic field.

These findings suggest that birds use magnetic information alongside solar cues to orient themselves during flight.

How Magnetic Signals May Reach the Brain

After establishing a link between the liver cells and navigation, the researchers looked for a way the information could travel to the brain.

Source: Sciencedaily