Obesity Care

Obesity-related immune dysfunction linked to increased cancer risk

Researchers at Saint Louis University’s (SLU) School of Medicine have revealed a critical link between immune system dysfunction and an elevated risk of cancer in people living with obesity. The team found that T-cell dysfunction, a key component of immune health, plays a central role in this heightened risk.

T cells, a type of white blood cell classified as lymphocytes, are essential to the body’s immune system, defending against infections and cancer. Dr Ryan Teague, professor of molecular microbiology and immunology at SLU, and his research team are investigating how obesity impacts T-cell function and impairs immune surveillance—the body’s ability to detect and eliminate malignant cells before they develop into tumours.

The team’s findings, published in Nature Communications, were the result of a study led by Dr Teague and co-authored by Alex Piening, an M.D./Ph.D. candidate at SLU. The study demonstrated that obesity-related T-cell dysfunction prevented these immune cells from recognising and attacking tumour cells, resulting in a higher susceptibility to cancer in mice with obesity exposed to carcinogens. Now, the researchers are working to pinpoint the specific metabolic mechanisms associated with obesity that impair T-cell function.

Dr Teague’s lab focuses on identifying obstacles to effective cancer immunotherapy and developing strategies to overcome them, with the goal of improving outcomes for individuals undergoing these treatments. His team is particularly interested in understanding how obesity affects the efficacy of immunotherapies.

“Immunotherapy boosts a patient’s immune system by targeting T cells and reinvigorating them. Paradoxically, immunotherapy is often more successful in patients with obesity, where the immune system isn’t functioning quite as well,” Dr Teague explained. “Our research explains this paradox by showing that, in the context of obesity, developing tumours are only required to evade a weakened immune system. These tumours, therefore, are not as well adapted to escape the reinvigorated T cells stimulated during immunotherapy, making them more vulnerable to destruction.”

The study also highlights the role of advanced technology in achieving these findings. Single-cell RNA sequencing, a technique that allows researchers to examine the activity within individual immune cells, was instrumental in uncovering the details of T-cell dysfunction.

“We learned that the dysfunction in these T cells lies in their inability to kill tumours. The genes responsible for this activity were not being activated,” Dr Teague noted. “Additionally, the cells lacked the ability to acquire the metabolic functions required to sustain anti-tumour activity.”

SLU’s investment in single-cell RNA sequencing technology has been a driving force behind these discoveries. The Department of Molecular Microbiology and Immunology is leveraging this cutting-edge approach to advance its understanding of cancer and the immune system, bringing researchers closer to innovative treatments and potential cures.

This research underscores the complexity of the relationship between obesity, immune function, and cancer risk, while also offering hope for improved immunotherapy strategies tailored to individuals living with obesity.

Study finds physical activity boosts brain health and cuts dementia risk

Staying physically fit can significantly lower the risk of developing dementia and delay its onset by nearly 18 months, according to new research highlighting the critical role of exercise in boosting brain health. The findings offer hope, even for those genetically predisposed to dementia, revealing that maintaining a high level of fitness can reduce their risk by up to 35%.

The study, published in the British Journal of Sports Medicine, underscores the importance of physical fitness across a lifetime as a key strategy to lower the likelihood of developing dementia. It found that individuals with the highest levels of cardiorespiratory fitness (CRF)—a measure of the body’s ability to deliver oxygen to muscles during exercise—had better cognitive function and a lower risk of dementia compared to those with lower fitness levels.

Study Details

The research analysed data from 61,214 participants aged 39 to 70 who joined the UK Biobank study between 2009 and 2010. At the time of enrolment, none of the participants had been diagnosed with dementia. Over a follow-up period of up to 12 years, the researchers monitored their health outcomes.

To assess their physical fitness, participants completed a six-minute stationary bike test, measuring their CRF levels. Cognitive function was evaluated through neuropsychological tests, and genetic predisposition to dementia was calculated using a polygenic test for Alzheimer’s disease risk.

The study’s authors wrote, “Our study shows that higher CRF is associated with better cognitive function and decreased dementia risk. Moreover, high CRF may buffer the impact of genetic risk of all dementia by 35%.”

The researchers also noted that individuals with high CRF experienced a delay in dementia onset of approximately 1.48 years. The study was led by Professor Weili Wu from the Ageing Research Centre at the Karolinska Institute in Stockholm, Sweden.

Implications for Dementia Prevention

The findings provide further evidence supporting the role of a healthy lifestyle in reducing dementia risk. Organisations dedicated to dementia care emphasised the study’s importance in showing how physical activity can be a protective factor against cognitive decline.

“This research emphasises that exercise is an important part of maintaining a healthy lifestyle and could reduce the risk of developing dementia later in life,” said Dr Richard Oakley, Associate Director of Research and Innovation at the Alzheimer’s Society. “What is particularly promising about this study is that exercise also appears to reduce dementia risk in people who have a higher genetic risk of developing Alzheimer’s disease.”

The Lancet Commission on dementia, in its July report, identified physical inactivity as one of 14 modifiable risk factors for dementia. Other factors include hearing loss, low levels of education, air pollution, social isolation, and depression.

Dr Jacqui Hanley, Head of Research at Alzheimer’s Research UK, commented, “This new research highlights how good cardiorespiratory fitness, a key measure of overall physical health, could help lower the risk of developing dementia in the future. However, it is important to note that we don’t know if there is a direct link between cardiorespiratory fitness and reduced dementia risk. More research is needed to find out exactly how it affects the brain.”

Observational Nature of the Study

The researchers emphasised that their findings were observational and do not definitively establish a causal relationship between higher CRF and reduced dementia risk. Nevertheless, they suggest that improving cardiorespiratory fitness could be a viable strategy for preventing dementia, even in individuals with a high genetic predisposition for Alzheimer’s disease.

“Enhancing CRF could be a strategy for the prevention of dementia,” the authors concluded, adding weight to the growing body of evidence that physical activity plays a critical role in supporting cognitive health.

Call to Action

Dementia charities and health experts encourage people to adopt a proactive approach to reducing their dementia risk by incorporating regular exercise into their lives, avoiding smoking, limiting alcohol intake, and maintaining overall physical and mental health.

This study provides yet another compelling reason to make fitness a priority—not just for physical well-being but also for preserving cognitive health in the years to come.

Kimchi found to significantly reduce body fat and help tackle obesity

Obesity, a significant global health challenge, affects approximately 16% of the world’s population—equivalent to around 890 million individuals. Recognised by the World Health Organization (WHO) as a critical health issue, obesity is linked to a diminished quality of life and adverse effects on overall health. To address this pressing concern, researchers at the World Institute of Kimchi in South Korea have been actively studying the potential health benefits of kimchi, a traditional Korean fermented food. Their findings, published in leading international journals, including the Journal of Functional Foods, highlight kimchi’s promising role in reducing body fat and its potential as a dietary strategy for obesity management.

Evidence from Preclinical Studies

Initial investigations into the anti-obesity effects of kimchi yielded striking results. In animal models of obesity, diets incorporating kimchi led to a remarkable 31.8% reduction in body fat. These findings underscore kimchi’s potential as a functional food for managing body weight.

Insights from Longitudinal Population Studies

Data from the Korea Genome and Epidemiology Study (KoGES), a 13-year longitudinal research effort involving a large cohort, further reinforced kimchi’s benefits. Among middle-aged males, appropriate consumption of kimchi was associated with a 15% reduction in body mass index (BMI) and a 12% decrease in obesity incidence. This study was published in Food & Function and BMJ Open and received international attention, including coverage by NBC News.

Clinical Trial: Kimchi and Gut Health

A recent clinical trial led by Dr. Sung-Wook Hong from the Kimchi Functionality Research Group, in collaboration with Pusan National University Hospital, investigated the effects of kimchi on body fat and gut microbiomes. The trial involved 55 adults with overweight (both males and females) with BMIs ranging from 23 to 30 kg/m². Over three months, participants consumed 60g of kimchi daily via capsules containing freeze-dried cabbage kimchi fermented at 4℃ for two weeks.

The results were compelling:

1. Participants consuming kimchi experienced a 2.6% reduction in body fat.
2. By contrast, those in the control group saw a 4.7% increase in body fat.

This difference was statistically significant, indicating the efficacy of regular kimchi consumption.

Gut Microbiome Modulation

The trial also revealed notable changes in gut microbiota. Participants who consumed kimchi showed:

1. An increase in Akkermansia muciniphila, a beneficial bacterium associated with gut health and reduced obesity risk.
2. A decrease in Proteobacteria, which are linked to obesity.

These findings suggest that kimchi’s anti-obesity effects may be mediated through gut microbiota modulation, providing a dual benefit for weight management and gastrointestinal health.

Expert Commentary and Future Directions

Dr. Hae-Choon Chang, Director of the World Institute of Kimchi, emphasised the importance of these findings:
“The results of a preclinical study and a clinical trial have systematically verified the anti-obesity effects of kimchi and present scientific evidence that would help to make the excellent properties of kimchi widely known, thereby laying the foundation for the growth of kimchi as a health food well recognised around the world.”

She added: “We will continue to devote our time, effort, and resources towards scientific research to reinforce the health-functional properties of kimchi, in improving gastrointestinal health in addition to its immune-enhancing and anti-cancer effects, thus firmly establishing the role of kimchi as a global health food.”

The findings from this clinical trial were published in the October 2024 issue of the Journal of Functional Foods.

Kimchi: A Cultural and Health Icon

In recognition of its cultural and health significance, South Korea designated 22 November as “Kimchi Day” in 2020. This commemorative day celebrates kimchi as the first Korean food to gain such recognition for its unique health properties. Since then, Kimchi Day has been celebrated internationally, with festivals held in countries including the U.S., U.K., Argentina, and Brazil.

Kimchi’s established benefits and increasing global recognition underscore its potential as a dietary staple for promoting health and combating obesity. With ongoing research, this traditional food is poised to play a central role in global health strategies.

Effective screen time rules reduce obesity risk in children, research confirms

Families are being urged to establish clear and consistent screen-time rules for their children to promote healthier habits, improve sleep, and reduce the risk of obesity, according to new research from the University of Auckland and St George’s, University of London.

The study, published in the European Journal of Public Health, highlights that family screen-time rules are an effective tool for reducing young children’s screen use and ensuring they get adequate sleep—both of which are linked to a lower risk of developing obesity.

“These findings suggest that promoting family screen-time rules is a helpful strategy to support healthier habits in children and address obesity on a larger scale,” says lead author Dr Ladan Hashemi, an honorary senior researcher in social and community health at Waipapa Taumata Rau, University of Auckland.

The researchers advise parents and caregivers to establish straightforward screen-time rules early in a child’s life. These guidelines should focus on three key areas:

1. Quality: Limiting the types of programmes children are permitted to watch.
2. Quantity: Setting clear limits on the amount of time children can spend using televisions, tablets, and other devices.
3. Timing: Defining specific times when children can and cannot use screens, such as avoiding screens before bedtime.

“Our findings suggest that having all three rules in place is most effective in encouraging healthier habits, like reducing screen time and supporting better sleep,” explains Dr Hashemi. “These simple but combined actions can have a lasting, positive impact on your child’s overall health and help lower their risk of obesity.”

The Broader Impact of Excessive Screen Time

Research has repeatedly shown that excessive screen time, especially at a very young age, is associated with a range of adverse outcomes. These include shortened attention spans, emotional and behavioural challenges, language development delays, disrupted sleep patterns, and increased obesity risk.

The new study was motivated by the growing prevalence of childhood obesity in New Zealand and globally. It underscores the importance of improving sleep as part of addressing the obesity epidemic. Prior research has established a strong link between insufficient sleep and obesity, with children who spend less time on screen devices generally experiencing better sleep. The researchers noted that families with screen-time rules often have corresponding guidelines around bedtimes, further supporting improved sleep quality for children.

Study Methodology and Findings

The study analysed data from 5,733 children and their mothers who participated in the Growing Up in New Zealand longitudinal study. It specifically examined the impact of family screen-time rules implemented when children were two years old on their obesity outcomes at four-and-a-half years old.

The findings revealed that screen-time rules were associated with reduced screen use and better sleep in children, both of which contribute to healthier weight outcomes. However, the study also identified significant socio-economic factors—such as poverty and food insecurity—that influenced screen use and childhood obesity. When these factors were accounted for, the direct association between screen time and obesity weakened.

Addressing Underlying Issues

The researchers emphasised that tackling childhood obesity requires more than just screen-time guidelines. Broader societal challenges, such as poverty and food insecurity, play a pivotal role in determining children’s health outcomes. Families facing financial hardship often struggle to access nutritious food and other resources needed to establish healthy routines, including screen-time rules.

“Programmes that offer resources and support to financially disadvantaged families, like those that improve access to healthy foods, are essential for helping these families establish and maintain effective screen-use guidelines,” says Dr Hashemi.

This research underscores the need for a multi-faceted approach to combat childhood obesity—one that combines practical strategies like screen-time rules with broader efforts to address the socio-economic factors driving the epidemic.

By taking these steps, families can not only improve their children’s overall health but also contribute to a wider societal effort to reduce childhood obesity rates.

Epigenetic changes in fat cells shed light on why weight loss is hard to sustain

Even after significant weight loss, fat cells retain a ‘memory’ of obesity, according to groundbreaking research published in Nature. This discovery sheds light on why maintaining weight loss can be so challenging, underscoring the need for long-term support for individuals who achieve significant weight reductions.

The Epigenetic Memory of Obesity

The study reveals that obesity triggers changes in the epigenome—chemical modifications to DNA and proteins that regulate gene activity. These epigenetic alterations disrupt the normal functioning of fat cells, impairing their ability to operate as they would in a body without obesity. Crucially, these changes persist even after weight loss brings body weight to a healthy level.

This persistence highlights the complexity of obesity as a condition, suggesting that maintaining weight loss often requires more than personal effort. Co-author Laura Hinte, a biologist at ETH Zurich, explained that the findings emphasise the need for additional support. “It means that you need more help, potentially,” she said, adding that this reinforces the idea that “it’s not your fault.” By uncovering the molecular underpinnings of this phenomenon, the study offers an explanation for the enduring challenges many individuals face after weight loss.

Exploring the Molecular Mechanisms

To investigate why weight is often regained after loss, researchers examined fat tissue from individuals with severe obesity and compared it to fat tissue from people who had never experienced obesity. They discovered significant differences in gene activity: some genes were more active in the fat cells of individuals with obesity, while others were less active.

Even after weight-loss surgery, the genetic activity in fat cells from participants with a history of obesity remained altered. Two years post-surgery, despite substantial weight reductions, the fat cells still displayed an obesity-linked pattern. Similar results were observed in mice, further supporting the findings.

The Lasting Impact of Obesity on Fat Cells

The research pinpointed specific genes that were affected by obesity. Genes that promote inflammation and fibrosis (the formation of stiff, scar-like tissue) were dialled up, while those essential for normal fat cell function were suppressed. These changes were traced to alterations in the epigenome, which dictate whether specific genes are switched on or off.

The durability of this ‘memory’ was tested by placing mice with obesity on a diet. Despite becoming lean again, their fat cells continued to exhibit obesity-related epigenetic changes months later. Co-author Ferdinand von Meyenn, an epigenome specialist at ETH Zurich, noted that while it is unclear how long the body retains this memory, “there may be a time window when this memory will be lost,” although “we don’t know” for certain. This lingering effect demonstrates how deeply obesity can alter the body at the cellular level.

Effects of Fat Cell Memory on Metabolism

The persistent memory of obesity has profound implications for metabolism. Fat cells from mice formerly with obesity absorbed more sugar and fat than those from control mice that had never had obesity. Moreover, when placed on a high-fat diet, the mice formerly with obesity regained weight more quickly than their counterparts who had never had obesity.

While these findings are striking, the study stops short of proving a direct causal link between epigenetic changes and altered fat cell function. Scientists such as Evan Rosen, a biologist at Beth Israel Deaconess Medical Center in Boston, pointed out that although the research provides a valuable list of epigenetic alterations, determining which changes drive the fat cells’ lingering memory will be challenging. Von Meyenn acknowledged this limitation, stating that “it’s not yet a causal link,” but rather “correlation” that his team continues to explore.

Implications for Weight Loss and Obesity Stigma

The study’s findings have broader implications for addressing obesity-related stigma. They suggest that the biological changes caused by obesity create long-term challenges that cannot simply be overcome with willpower alone. Von Meyenn stressed the importance of preventing obesity in the first place, explaining that while people who lose weight can remain lean, “it will require a lot of effort and energy to do that.”

By uncovering the epigenetic mechanisms that underlie obesity and its lingering effects, the research may pave the way for improved treatments and support systems. This, in turn, could help reduce stigma and foster greater understanding of the biological challenges faced by individuals seeking to manage their weight long-term.

Stress hormones may be the key to understanding how obesity causes diabetes, researchers reveal

A groundbreaking study from Rutgers Health, in collaboration with several institutions, suggests that stress hormones, rather than impaired cellular insulin signalling, might be the primary cause of obesity-related diabetes. This research, published in Cell Metabolism, challenges the traditional view of how obesity-induced insulin resistance develops and introduces novel perspectives on potential treatment approaches.

“We have been interested in the basic mechanisms of how obesity induces diabetes. Given that the cost of the diabetes epidemic in the U.S. alone exceeds $300 billion per year, this is a critically important question,” said Christoph Buettner, chief of endocrinology, metabolism, and nutrition at Rutgers Robert Wood Johnson Medical School and the senior author of the study.

Challenging Long-Standing Beliefs About Obesity and Diabetes

Historically, scientists have attributed the development of diabetes in people with obesity to disrupted insulin signalling within liver and fat cells. However, this new study offers an alternative explanation, highlighting the role of the body’s sympathetic nervous system (SNS) – commonly associated with the “fight or flight” response. According to the researchers, overeating and obesity stimulate this system, leading to increased levels of the stress hormones norepinephrine and epinephrine, which seem to interfere with insulin’s effects. Importantly, they observed that this interference occurs even when cellular insulin signalling remains intact.

Through experiments on mice, the researchers found that overeating rapidly increases the stress hormone norepinephrine within days, indicating just how quickly excess food can stimulate the SNS.

The Role of Stress Hormones in Disease Development

To better understand how this hormone surge influences disease progression, the researchers used a new type of genetically engineered mice that are identical to regular mice except for one critical difference: they are unable to produce catecholamines, the primary stress hormones, outside their brain and central nervous system.

The study showed that when these genetically modified mice were fed an obesity-inducing, high-fat and high-sugar diet, they gained just as much weight as their regular counterparts. Yet, they did not develop metabolic diseases typically associated with obesity.

“We were delighted to see that our mice ate as much because it indicates that the differences in insulin sensitivity and their lack of metabolic disease are not due to reduced food intake or reduced obesity but due to the greatly reduced stress hormones. These mice cannot increase stress hormones that counteract insulin; hence, insulin resistance does not develop during obesity development.”

Explaining the Variation in Diabetes Development

The findings may provide insight into why some people living with obesity develop diabetes while others do not, and why stressful conditions can worsen diabetes, even without significant weight gain. Buettner noted: “Many types of stress – financial stress, marital stress, the stress associated with living in dangerous areas or suffering discrimination or even the physical stress that comes from excessive alcohol consumption — all increase diabetes and synergize with the metabolic stress of obesity.”

He added, “Our finding that even obesity principally induces metabolic disease via increased stress hormones provides new insight into the common basis for all these factors that increase the risk of diabetes. Stress and obesity, in essence, work through the same basic mechanism in causing diabetes, through the actions of stress hormones.”

A Paradigm Shift in Understanding Insulin Resistance

While it has long been recognised that catecholamines can impair insulin action, this study suggests that heightened activity of these stress hormones might be the fundamental driver of insulin resistance in obesity. Stress hormones increase glucose and lipid levels in the bloodstream, while insulin typically works to lower them. The study reveals that insulin signalling remains intact in many cases of insulin resistance associated with obesity. Instead, the heightened presence of stress hormones acts like an “accelerated gas pedal,” pushing blood sugar and fat levels up, despite insulin’s continued attempts to reduce them.

“Some colleagues are at first surprised that insulin resistance can exist even though cellular insulin signalling is intact,” Buettner explained. “But let’s not forget that the gas pedal effects of stress hormones are exerted through very different signalling pathways than insulin signalling. That explains why the ability of insulin to ‘brake’ and reduce the release of sugar and fat into the bloodstream is impaired even though insulin signalling is intact because stress signalling is predominant.”

Potential for New Treatments

These findings open the door to considering medications that reduce catecholamines – encompassing all stress-related hormones produced by the SNS and adrenal glands – as a possible treatment for diabetes. However, medicines currently used to block catecholamines for high blood pressure have not shown significant benefits for diabetes, possibly due to their inability to target the relevant receptors or their complex interactions within the brain and body.

Buettner and Kenichi Sakamoto, the study’s first author and an assistant professor of endocrinology at Robert Wood Johnson Medical School, are now preparing to validate these findings in human studies. They are also exploring the role of the SNS in other forms of diabetes, including Type 1 diabetes. “We would like to study if short-term overfeeding, as some of us experience during the holidays by gaining five to 10 pounds, increases insulin resistance with heightened sympathetic nervous system activation,” Buettner said.

A New Direction for Diabetes and Metabolic Disease Research

Ultimately, this research could lead to a new focus on reducing stress hormones as a therapeutic strategy to tackle insulin resistance, diabetes, and metabolic diseases, shifting away from targeting insulin signalling alone.

“We hope this paper provides a different take on insulin resistance,” Buettner concluded. “It may also explain why none of the drugs currently used to treat insulin resistance, except insulin itself, directly increases cellular insulin signalling.”

By highlighting the potential for stress hormone reduction to prevent or treat diabetes, these findings represent a substantial step forward in understanding and addressing the complex relationship between obesity and diabetes.

Study finds weight-loss surgery in adolescents leads to major long-term health benefits

A landmark study spanning 18 years and costing $29 million has found that weight-loss surgery in adolescents with severe obesity can lead to long-lasting health improvements, particularly in the remission of type 2 diabetes. The research, funded by the National Institutes of Health (NIH) and published in the New England Journal of Medicine, highlights how surgical interventions in young people bring about more sustained benefits compared to adults who undergo the same procedures.

With a rising prevalence of severe obesity in young people, researchers underscore the need to understand the benefits and risks of medical and surgical options. “These findings are essential as effective treatment options for severe paediatric obesity remain rare,” said Dr Thomas Inge, the study’s principal investigator and surgeon-in-chief at Lurie Children’s Hospital in Chicago. “Robust data on the outcomes of modern bariatric procedures are invaluable for clinicians and families considering ways to support adolescents facing obesity, especially in cases of rapid weight gain,” added Dr Inge, who also directs the hospital’s bariatric surgery programme.

The trial, which ran from 2006 to 2012, included approximately 260 adolescents aged 13 to 19, who underwent bariatric surgery at one of five centres in the United States, including Cincinnati Children’s, Texas Children’s Hospital in Houston, Children’s Hospital of Alabama in Birmingham, the University of Pittsburgh Medical Center, and Nationwide Children’s Hospital in Columbus, Ohio.

Adolescents with severe obesity who had bariatric surgery before age 19 experienced sustained weight loss a decade later. Additionally, they showed significant resolution of obesity-related health conditions, including type 2 diabetes, hypertension, and elevated cholesterol. Researchers reported that participants maintained substantial reductions across these conditions, with an average 20% decrease in body mass index (BMI), a 55% reduction in type 2 diabetes, a 57% decrease in hypertension, and a 54% improvement in abnormal cholesterol.

The benefits of surgery appeared similar between those who underwent gastric bypass and those who received sleeve gastrectomy, indicating both procedures are effective in treating obesity-related health issues in young people.

Importantly, the study found that the 55% reduction in type 2 diabetes in adolescents following surgery was far greater than that observed in adults who had undergone the same procedures. Recent NIH-funded studies in adults showed only an 18% decrease in diabetes after seven years and 12.7% after 12 years. Given the rapid progression of type 2 diabetes in young people, this study demonstrates the considerable long-term health benefits of bariatric surgery when undertaken during adolescence.

“This study underscores that surgical treatment should be considered earlier in the course of severe obesity,” Dr Inge remarked. However, he highlighted a critical barrier to access: fewer than 1% of eligible adolescents with severe obesity receive surgery due to parental reservations and other factors. “We should advocate for early intervention and ensure that adolescents have access to effective therapies to mitigate the progression of obesity-related conditions, such as type 2 diabetes and hypertension,” Dr Inge emphasised. In addition to his role at Lurie Children’s Hospital, Dr Inge serves as a professor of surgery and paediatrics at Northwestern University Feinberg School of Medicine in Chicago.

The study has received praise from other experts in adolescent weight management, who recognise the growing importance of effective interventions for severe obesity in young people. “The rate of obesity continues to rise in children, threatening to impact future life expectancy and healthcare costs,” noted Dr Kirk Reichard, surgical director of the bariatric surgery programme at Nemours Children’s Hospital in Wilmington, Delaware. Although not directly involved in the study, Dr Reichard underscored the critical need to address paediatric obesity. “While efforts to address prevention are critical, the reality is that 20% of American children are now affected by obesity and need our help,” said Dr Reichard, who is also a clinical professor of surgery and paediatrics at Sidney Kimmel Medical College of Thomas Jefferson University in Philadelphia.

Another expert, Dr Andrea Coviello, an endocrinologist and director of the weight management programme at the University of North Carolina School of Medicine in Chapel Hill, pointed out that long-term data on bariatric surgery in younger patients has been limited. “There has been a lack of long-term data on the benefits and risks of bariatric surgery in younger patients,” Dr Coviello said, adding that “this study helps to fill in knowledge gaps that may help healthcare providers and parents to make informed decisions about healthcare options for children with obesity and obesity-related conditions such as type 2 diabetes.”

Dr Coviello encouraged parents to seek guidance from paediatricians and weight-loss specialists if their children are affected by obesity, particularly if they experience related health issues such as type 2 diabetes or high blood pressure. “Appropriate care and weight loss earlier may significantly improve their child’s health in the longer term,” she noted.

The findings of this study hold significant implications for addressing severe obesity in adolescents, demonstrating that early surgical intervention can lead to sustained health improvements and potentially prevent the worsening of obesity-related conditions later in life.

Surge in endometrial cancer among younger women linked to rising obesity rates

Endometrial cancer, historically more prevalent in post-menopausal women, has seen a significant and concerning rise in cases among women under the age of 40. This trend has puzzled reproductive health experts, prompting urgent research into its causes.

Researchers from UCI Health now report a strong correlation between this surge in endometrial cancer among younger women and the rapidly increasing obesity rates. They argue that this trend demands immediate public health interventions to reverse the alarming trajectory.

Between 2001 and 2018, cases of endometrial adenocarcinoma—the most common form of endometrial cancer—rose by 137% among women aged 20 to 29, and by 71% among those aged 30 to 39, according to data presented at a recent American Society of Clinical Oncology (ASCO) conference. The increases were even more pronounced among younger Black women and Latinas.

Over the same period, obesity rates surged, rising by 7.5% per year among women aged 20 to 29, and by 4.5% annually among those aged 30 to 39, the study revealed.

A Public Health Emergency

“Endometrial cancer is the most common gynaecological cancer encountered in the United States,” notes Dr Krishnansu Tewari, a UCI Health gynaecologic oncologist and co-author of the study.

Once primarily seen in older women, endometrial adenocarcinoma is now the sixth most common cancer in women overall, and it is becoming increasingly deadly. It is projected to cause more than 13,000 deaths this year, up from 3,000 annual deaths in the late 1980s.

“This represents a public health emergency,” states Dr Alex Francoeur, the lead author of the study. Francoeur emphasises the need for a concerted effort to educate women and healthcare providers about the risks posed by obesity in developing endometrial adenocarcinoma.

Analysing Two Decades of Data

The retrospective study analysed data from more than 580,000 cases of endometrial adenocarcinoma in the U.S. over the last two decades. Researchers then compared these findings with data on obesity rates among women over the same period.

The results revealed a particularly strong link between rising obesity rates and increased incidences of cancer in younger women, especially women of colour.

“When examining trends by race and ethnicity, we found that the rate of endometrial cancer in Black women has increased by 25% since 2001, and by 17% in Hispanic women,” says Francoeur, who is a gynaecologic oncology fellow at the UCI School of Medicine’s Department of Obstetrics & Gynaecology.

Although further research is needed to establish a direct causal link, the study’s data strongly suggest the need for targeted public health initiatives aimed at educating women and reducing obesity rates.

Raising Awareness is Key

“Action is needed to address the impact of obesity on endometrial cancer,” Francoeur stresses. She advocates for the following measures:

1. Raising awareness: “Sharing this information with gynaecology patients and providing early education on the risk factors associated with obesity and reproductive health is crucial.”
2. Encouraging weight management: “Discussions about weight should become a routine part of health maintenance, similar to the way cervical cancer screenings and mammography are standard components of preventive care.”

Francoeur highlights that there are many ways for individuals to receive support, including consulting a dietitian, considering medications that target weight loss, and exploring surgical options to manage obesity.

Fertility-Sparing Treatment Options

For individuals of childbearing age diagnosed with endometrial cancer, surgery is not always the only treatment option.

“With early-stage endometrial cancers, we can often manage the disease with hormone therapy, allowing patients to preserve their ability to conceive,” explains Tewari, who is also a professor and chief of the Division of Gynaecologic Oncology in the Department of Obstetrics & Gynaecology.

Progestin therapy, a hormone treatment, can sometimes be used to shrink or eliminate the cancer temporarily in those wishing to maintain fertility. The most commonly used medications in this treatment are:

1. Medroxyprogesterone acetate, administered as an injection or a pill.
2. Megestrol acetate, available as a pill or liquid.

However, Tewari cautions that this approach is not yet a standard treatment and may increase the risk of cancer progression. “It’s vital to confirm the grade of the cancer with a gynaecologic oncologist and a pathologist, and to consult with a fertility specialist before beginning progestin therapy,” he advises.

Study reveals sweet tooth linked to increased risk of depression, diabetes, and stroke

Individuals with a preference for sweet foods and sugary drinks face a significantly higher risk of developing conditions such as depression, diabetes, and stroke, according to groundbreaking research from the University of Surrey. The study, which highlights the complex interplay between dietary habits and long-term health, was recently published in the Journal of Translational Medicine. 

The research team analysed anonymised dietary data from 180,000 volunteers from the UK Biobank, a large-scale biomedical database, and utilised artificial intelligence (AI) to categorise participants into three distinct dietary profiles based on their food preferences:

1. Health-conscious: This group prioritises fruits, vegetables, and plant-based foods, showing a clear preference for healthier options over animal-based or sweet foods.
   
2. Omnivore: These individuals enjoy a balanced variety of foods, including meats, fish, vegetables, and occasional sweets and desserts.
   
3. Sweet tooth: This group has a strong preference for sugary foods and drinks, while showing less interest in healthier options such as fruits and vegetables.
   

To explore how these preferences might impact health, the researchers examined blood samples from participants, measuring 2,923 proteins and 168 metabolites. These biological markers offer insight into how the body processes nutrients and its overall functioning. Proteins, for instance, are crucial for bodily processes such as immune defence, muscle function, and brain activity. Metabolites are small molecules produced during digestion and other metabolic processes, providing a snapshot of the body’s internal health.

By comparing the levels of these proteins and metabolites across the three groups, the researchers uncovered distinct biological differences, offering a deeper understanding of how diet impacts health.

Professor Nophar Geifman, lead author of the study and Professor of Health and Biomedical Informatics at the University of Surrey, explained, “The foods that people like or dislike appear to have a direct link to their health. If someone regularly chooses cakes, sweets, and sugary drinks, our study suggests that this preference may have detrimental effects on their overall well-being.”

The study revealed that individuals in the sweet tooth group were 31% more likely to experience depression. Additionally, they had notably higher rates of diabetes and vascular heart conditions compared to those in the other two groups.

“Importantly, by using data-driven AI methods, we were able to identify these groups based on food preferences, and these groups turned out to be quite meaningful in relation to health outcomes and biological markers,” added Professor Geifman.

Sugar is often an integral part of many people’s diets, and the study reinforces concerns about the widespread consumption of processed sugar. “As a society, we should be more mindful of our food choices. While it is not about dictating what people should eat, our goal is to provide information that helps individuals make informed decisions about their diets,” said Geifman.

In addition to examining proteins and metabolites, the researchers also reviewed standard blood biochemistry tests for participants in each dietary group. The results were concerning for the sweet tooth group, who displayed elevated levels of C-reactive protein, a marker of inflammation, as well as higher glucose levels and poor lipid profiles, which are risk indicators for diabetes and cardiovascular disease.

In contrast, the health-conscious group, which consumed more dietary fibre, exhibited lower risks of heart failure, chronic kidney disease, and stroke. Meanwhile, the omnivore group demonstrated moderate health risks, falling between the other two groups.

Professor Geifman further noted, “In those with a sweet tooth, we found several red flags in their blood tests, including markers for inflammation and poor lipid profiles. These are significant warning signs for serious conditions like diabetes and heart disease.”

The findings add to the growing body of evidence highlighting the negative impact of excessive sugar consumption on health. According to the British Nutrition Foundation, individuals in the UK consume between 9% to 12.5% of their daily calorie intake from “free sugars”—these are sugars added to foods and drinks. Popular sources of free sugars for adults include biscuits, cakes, pastries, and fruit pies, while sugary soft drinks and alcoholic beverages are also major contributors.

This study underscores the urgent need for greater awareness around dietary habits and their long-term implications on mental and physical health. While occasional treats may not seem harmful, consistently choosing sugar-laden foods and drinks could increase the likelihood of developing serious health conditions over time.

As Professor Geifman emphasised, “These findings serve as a reminder that the choices we make about what we eat can have lasting consequences on our health. While no one is saying people should entirely eliminate their favourite foods, moderation and a focus on healthier options could greatly reduce the risk of these debilitating conditions.”

This new research provides a compelling argument for reconsidering dietary habits, particularly for those with a sweet tooth, and for taking proactive steps to improve overall well-being through mindful eating.

Daily Brazil nut consumption may reduce inflammation and support gut health, new study suggests

Brazil nuts are one of the most concentrated sources of selenium, a trace mineral that plays a crucial role in the body’s antioxidant defences, immune response, and thyroid hormone metabolism. Selenium deficiency has been linked to several health issues, including chronic inflammation and impaired gut health.

Low levels of selenium in the bloodstream have been associated with inflammation-related conditions, including gut health challenges. Research has also identified connections between obesity, inflammation, and gut issues such as increased intestinal permeability, commonly known as “leaky gut.” This condition may occur when inflammation and body fat levels rise, causing the tight junctions in the cells lining the intestines to loosen. When these junctions become less effective, antigens, toxins, and bacteria may enter the bloodstream, triggering further inflammation, thus creating a harmful cycle where obesity exacerbates intestinal permeability, and vice versa.

In a recent study, researchers examined the impact of daily consumption of Brazil nuts on inflammation and intestinal permeability, specifically focusing on women living with overweight or obesity, during an 8-week calorie-restricted diet. The study’s findings, published in The Journal of Nutrition, suggest that eating 8 grams of Brazil nuts per day could improve these health markers, likely due to their rich selenium content.

The Brazil nuts used in the study were sourced from Amazonas, Brazil, and donated by ECONUT. However, attempts to contact ECONUT for comment were unsuccessful at the time of publication, and their involvement in the study was not noted as a conflict of interest.

The Study’s Design and Findings

The study was conducted by researchers from the Department of Nutrition and Health at the Universidade Federal de Viçosa in Brazil between June 2019 and September 2021. It involved 56 women aged 20 to 55, with an average age of 34 years. The women were categorised as either living with overweight or obesity, with 17.4% having specific cardiometabolic risk factors and 82.6% living with obesity, regardless of risk factors.

Participants were excluded from the study if they were pregnant, lactating, menopausal, athletes, vegan, had certain medical conditions, were using specific medications, had experienced significant weight changes, regularly consumed nuts, or had other potential study interferences.

The participants were divided into two groups: a control group and a Brazil nut group. Both groups followed a customised menu designed to provide approximately 500 fewer calories than their estimated daily energy requirements. The macronutrient composition of the diet was 50% carbohydrates, 30% fats, and 20% proteins, in line with established obesity management guidelines. Each participant was encouraged to lose at least 4 kilograms over the 8-week period.

To ensure a balanced intake of fats and calories, both groups were provided with controlled-ingredient salad dressings:

• Control group: Followed a nut-free diet and consumed 10 grams of soybean oil-based salad dressing with lemon daily.
• Brazil nut group: Consumed 8 grams of Brazil nuts (providing 347.2 micrograms of selenium) as a morning snack and 5 grams of canola oil-based salad dressing with lemon each day.

Participants received bi-weekly counselling from a nutritionist who monitored their diet adherence, including alcohol consumption. Any participant who failed to adhere to the study protocol was excluded from the final analysis.

Researchers measured inflammatory markers in the blood and selenium levels. Intestinal permeability was assessed using the lactulose/mannitol test (LM ratio), and statistical analyses were conducted to evaluate changes between the groups, with a 97% power to detect differences in intestinal permeability.

Brazil Nuts Associated with Reduced Inflammation and Improved Gut Health

Of the 56 women initially recruited, 46 completed the study. At the start, the control group had a higher intake of polyunsaturated fats compared to the Brazil nut group. During the 8-week intervention, the control group reduced their intake of saturated fats, while the Brazil nut group increased their intake of polyunsaturated fats and dietary fibre.

Both groups achieved similar calorie restrictions and experienced modest weight loss (approximately 3 kilograms) and small reductions in waist circumference. However, the Brazil nut group showed a significant increase in selenium levels, confirming adherence to their Brazil nut consumption.

Compared to the control group, the Brazil nut group exhibited lower levels of inflammatory markers, including C-reactive protein (CRP), tumour necrosis factor (TNF), interleukin-1β (IL-1β), and interleukin-8 (IL-8), indicating a reduction in systemic inflammation. In the Brazil nut group, CRP levels decreased from 7.1 mg/L to 5.6 mg/L over the 8 weeks, while the control group saw an increase in CRP levels from 8.0 to 9.4 mg/L. Although the exact mechanism behind these changes is not fully understood, it is likely linked to improvements in gut inflammation and intestinal permeability.

Women in the Brazil nut group who lost more weight also showed more pronounced reductions in CRP levels. Additionally, this group demonstrated lower lactulose excretion and LM ratio values, which are markers of improved intestinal permeability. However, these changes were not statistically significant when compared to the control group.

Further analysis revealed that higher blood selenium levels were associated with lower levels of IL-1β and IL-8, and changes in IL-8 were related to the LM ratio. These findings suggest that selenium levels may predict improvements in both systemic inflammation and gut permeability.

Study Limitations and Expert Insights

This study had certain limitations, including its small sample size, short duration, and the fact that it only included young to middle-aged women from Brazil. As a result, the findings may not be generalisable to other populations. The participants were also not blinded to their dietary interventions, the study was not randomised, and calorie restriction adherence was primarily self-reported, which may have introduced reporting errors.

Commenting on the study, registered dietitian Alyssa Simpson, RDN, CGN, CLT, who was not involved in the research, highlighted the need for further studies to isolate the effects of selenium from other dietary variables. She stated: “The findings indicate that selenium from Brazil nuts significantly influences inflammation and intestinal permeability, but the simultaneous increases in polyunsaturated fats and fibre intake complicate attributing the effects solely to selenium.”

Simpson suggested that a more controlled study design could help clarify the individual effects of selenium, polyunsaturated fats, and fibre on inflammation and gut health.

Dr. Thomas M. Holland, a physician-scientist from the RUSH Institute for Healthy Aging, added: “In this study, increased selenium levels correlated with reductions in inflammatory cytokines and improvements in intestinal permeability, which may enhance the absorption of nutrients.”

How Many Brazil Nuts Should You Eat Per Day?

Kiran Campbell, RDN, a medical nutrition advisor, explained that the human body cannot produce selenium, making dietary intake essential. While a single Brazil nut provides approximately 96 micrograms of selenium—nearly double the recommended daily intake for most adults—experts recommend consuming just 1–2 Brazil nuts per day to avoid exceeding the safe upper limit of 400 micrograms of selenium per day.

The European Food Safety Authority (EFSA) has set a lower upper limit of 255 micrograms of selenium daily for adult men and women. Consuming too much selenium can lead to toxicity, with symptoms such as brittle nails, hair loss, skin rashes, and neurological issues.

In conclusion, incorporating 1–2 Brazil nuts daily may offer practical and beneficial effects in reducing inflammation and supporting gut health, but they should be consumed as part of a well-rounded, healthy diet.

Endurance exercise transforms fat tissue and improves metabolic health in adults with obesity

A new study published in Nature Metabolism reveals that long-term endurance exercise leads to significant improvements in abdominal subcutaneous adipose tissue (aSAT) in individuals living with obesity. The study, conducted in the United States, aimed to isolate the benefits of exercise from weight loss, showing how regular physical activity improves cardiometabolic health.

The research found that those who exercised regularly had higher capillary density, fewer pro-inflammatory macrophages, and increased levels of proteins involved in angiogenesis, mitochondrial function, and fat storage. These changes suggest improved fat metabolism and enhanced overall metabolic health.

Notably, the study identified upregulation of oxidative phosphorylation and thermogenesis pathways, which increase energy metabolism in aSAT, providing a clearer picture of how regular exercise enhances metabolic function in people with obesity.

Background

In individuals with obesity, dysfunctional aSAT can contribute to insulin resistance and other metabolic problems. Issues such as reduced capillaries and increased inflammation in aSAT are linked to poor fat storage and the circulation of excess fatty acids, which can worsen metabolic health. By improving aSAT, particularly through enhanced fat storage and reduced inflammation, exercise could offer protective benefits.

This study aimed to fill the gap in understanding how long-term exercise affects aSAT, independent of weight loss, to explore how physical activity can improve cardiometabolic outcomes.

Study Overview

The researchers recruited 52 adults living with overweight or obesity. Participants were divided into exercisers and sedentary individuals based on their activity levels. The exercisers had consistently engaged in moderate to vigorous aerobic activity for over two years.

Key measures included body composition, fitness levels, and metabolic health markers. Fresh aSAT samples were collected to analyse structural and molecular differences between the groups.

Key Findings

Exercisers demonstrated significantly higher aerobic fitness and reported tenfold greater physical activity. They also had lower insulin resistance and higher HDL cholesterol levels compared to the sedentary group.

In terms of aSAT characteristics, exercisers had higher capillary density and increased levels of mitochondrial and ribosomal proteins, indicating better fat metabolism and energy production. Inflammatory markers were reduced, and proteins linked to metabolic dysfunction were lower in exercisers, suggesting improved tissue health.

Proteomic analysis identified 158 differentially expressed proteins, showing enhanced metabolic pathways in exercisers. These included the activation of the AMPK signalling pathway, essential for mitochondrial biogenesis and fat metabolism.

Conclusion

The study demonstrates that long-term endurance exercise leads to beneficial changes in fat tissue, boosting energy metabolism and improving cardiometabolic health in individuals with obesity. While short-term exercise offers some benefits, sustained physical activity is crucial for significant improvements in fat tissue function and overall health.

Yoyo dieting disrupts gut health and drives weight regain and inflammation

A review from Deakin University, Australia, published in Nutrients, reveals the profound effects of yoyo dieting (cycles of weight loss and regain) on gut health. The review highlights how weight cycling leads to gut inflammation, changes in microbiota, and adaptations in the sympathetic nervous system (SNS), which together drive weight regain.

Background

Obesity now affects over half of the global adult population and is linked to millions of deaths from diseases such as cardiovascular disease and type 2 diabetes. One of the major challenges in managing obesity is sustaining weight loss. Studies show that most people regain lost weight within five years, a phenomenon known as yoyo dieting or weight cycling.

This weight cycling not only increases the risk of obesity-related conditions but also disrupts gut health. The review points to emerging evidence that weight regain alters gut microbiota, with adaptive metabolic responses further complicating long-term weight management.

Gut Hormones and Energy Balance

Energy balance—the balance between intake and expenditure—is regulated by signals from the gut, pancreas, and adipose tissue. Many of these signals come in the form of peptide hormones that either promote satiety or stimulate hunger. After weight loss, individuals often experience lower levels of satiety hormones (PYY, GLP-1, and CCK) and higher levels of hunger hormones like ghrelin. This hormonal imbalance makes maintaining weight loss difficult, driving overeating and weight regain.

The review also discusses how weight loss can reduce enteroendocrine cells (EECs), which produce these key hormones, further impairing the body’s ability to regulate hunger and satiety.

The Role of the Gut Microbiota

The gut microbiota, which plays a critical role in energy regulation, also undergoes changes during and after weight loss. Beneficial bacteria that produce short-chain fatty acids (SCFAs), such as Christensenella and Lactobacillus reuteri, often decline during yoyo dieting, impairing satiety and promoting weight regain. Conversely, weight regain is associated with an increase in pro-inflammatory bacteria, such as Desulfovibrio and Ruminococcus, which contribute to metabolic disorders and gut inflammation.

Yoyo Dieting and Inflammation

Yoyo dieting exacerbates obesity-related chronic inflammation. Studies show that weight regain triggers inflammatory responses in the gut, marked by elevated levels of inflammatory markers such as TNF-α and IL-6. This inflammation can compromise gut barrier function, worsening metabolic health.

Improving Gut Health After Weight Loss

While yoyo dieting is associated with negative changes in the gut, weight loss has been shown to improve gut health by reducing inflammation and promoting the growth of beneficial bacteria like Akkermansia and Bifidobacterium. However, research indicates that the gut microbiota may take considerable time to return to a healthier state, leaving individuals vulnerable to weight regain during this period.

Research Gaps and Conclusions

Though animal studies have highlighted important links between yoyo dieting and gut health, more human studies are needed to fully understand how weight cycling affects the gut microbiota and weight regain. The review concludes that while weight loss can improve gut health, the molecular mechanisms behind these changes are still unclear, and more research is needed to develop effective strategies for preventing weight regain.

In conclusion, yoyo dieting disrupts gut health, leading to hormonal imbalances, inflammation, and microbiota changes that drive weight regain. Addressing these factors could be key to improving long-term weight maintenance and reducing obesity-related health risks.