Category: Diet and Nutrition

Celiac Disease: New Findings on the Effects of Gluten

Photo by Mariana Kurnyk

May 16 is International Celiac Day. Celiac disease is a chronic autoimmune condition that occurs in around 1% of the world’s population. It is triggered by the consumption of gluten proteins from wheat, barley, rye and some oats. A gluten-free diet protects celiac patients from severe intestinal damage. Together with colleagues, chemist Dr Veronica Dodero from Bielefeld University was able to determine new details on how certain gluten-derived molecules trigger leaky gut syndrome in celiac disease.

The key finding of the study: a particular protein fragment formed in active celiac disease forms nanosized structures, the so-called oligomers, and accumulates in a gut epithelial cell model. The technical name of the molecule is 33-mer deamidated gliadin peptide (DGP). The study team has now discovered that the presence of DGP oligomers may open the tightly closed gut lining, leading to the leaky gut syndrome. The study has now been published in the journal Angewandte Chemie.

Wheat peptides causing leaky gut

Gluten proteins cannot be completely broken down by the gut. This can lead to the formation of large gluten fragments (peptides) in our gut. In cases of active coeliac disease, researchers discovered that the enzyme tissue transglutaminase 2 (tTG2) present in humans modifies a specific gluten peptide, resulting in the formation of the 33-mer DGP. This usually happens in a part of our gut called the lamina propria. However, recent research has shown that this process can also occur in the gut lining.

‘Our interdisciplinary team characterized the formation of 33-mer DGP oligomers through high-resolution microscopy and biophysical techniques. We discovered the increased permeability in a gut cell model when DGP accumulates, reports Dr. Maria Georgina Herrera, the first author of the study. She is researcher at the University of Buenos Aires in Argentina and was a postdoctoral fellow at Bielefeld.

When the intestinal barrier is weakened

Leaky gut syndrome occurs when the lining of the intestine becomes permeable, allowing harmful substances to enter the bloodstream, leading to inflammatory responses and different diseases. In celiac disease, there’s debate about the early stages of increased permeability. The mainstream theory suggests that chronic inflammation in coeliac disease leads to a leaky gut. However, there is a second theory that proposes that gluten’s effects on gut lining cells are the primary cause. In this view, gluten directly damages the cells of the intestinal lining, making them permeable, which triggers chronic inflammation and potentially leads to celiac disease in predisposed people.

However, since gluten is consumed daily, what molecular triggers lead to the leaky gut in celiac disease patients? If 33-merDGP oligomers are formed, they may damage the epithelial cell network, allowing gluten peptides, bacteria, and other toxins to pass massively into the bloodstream, leading to inflammation and, in celiac disease, autoimmunity.

‘Our findings reinforce the medical hypothesis that impairment of the epithelial barrier promoted by gluten peptides is a cause and not a result of the immune response in celiac patients,’ says the lead author of the study, Dr Veronica Dodero from the Bielefeld Faculty of Chemistry.

The relationship between 33-mer DGP and Celiac Disease

Human leukocyte antigens (HLAs) are proteins found on the surface of cells in the body. They play a crucial role in the immune system by helping it distinguish between self (the body’s own cells) and non-self (foreign substances like bacteria or viruses). In celiac disease, two specific HLA proteins, namely HLA-DQ2 and HLA-DQ8, are strongly associated with the condition. The 33-mer DGP fits perfectly with HLA-DQ2 or HLA-DQ8 and triggers an immune response, leading to inflammation and small intestine villous atrophy. This strong interaction turns the DGP into what scientists call a superantigen. For those affected, a gluten-free diet is the only lifelong therapy.

Source: Bielefeld University

Nutrient’s Pathway into the Brain could be Used to Treat Neurological Disorders

Source: CC0

A University of Queensland researcher has found molecular doorways that could be used to help deliver drugs into the brain to treat neurological disorders. Dr Rosemary Cater from UQ’s Institute for Molecular Bioscience led a team which discovered that an essential nutrient called choline is transported into the brain by a protein called FLVCR2.

“Choline is a vitamin-like nutrient that is essential for many important functions in the body, particularly for brain development,” Dr Cater said.

“We need to consume 400-500mg of choline per day to support cell regeneration, gene expression regulation, and for sending signals between neurons.”

Dr Cater said that until now, little was known about how dietary choline travels past the layer of specialised cells that separates the blood from the brain.

“This blood-brain barrier prevents molecules in the blood that are toxic to the brain from entering,” she explained. “The brain still needs to absorb nutrients from the blood, so the barrier contains specialised cellular machines – called transporters – that allow specific nutrients such as glucose, omega-3 fatty acids and choline to enter. While this barrier is an important line of defence, it presents a challenge for designing drugs to treat neurological disorders.”

Dr Cater was able to show that choline sits in a cavity of FLVCR2 as it travels across the blood-brain barrier and is kept in place by a cage of protein residues.

“We used high-powered cryo-electron microscopes to see exactly how choline binds to FLVCR2,” she said. “This is critical information for understanding how to design drugs that mimic choline so that they can be transported by FLVCR2 to reach their site of action within the brain. These findings will inform the future design of drugs for diseases such as Alzheimer’s and stroke.”

The research also highlights the importance of eating choline-rich foods – such as eggs, vegetables, meat, nuts and beans.

The research is published in Nature and funded by the National Institutes of Health.

Source: University of Queensland

Study Reveals ‘Profound’ Link between Dietary Choices and Brain Health

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New research published in Nature has shown that a healthy, balanced diet was linked to superior brain health, cognitive function and mental wellbeing. The study, involving researchers at the University of Warwick, sheds light on how food preferences influence more than just physical health, and also significantly impact brain health.

With the help of machine learning, the researchers analysed a large sample of 181 990 participants from the UK Biobank, comparing their dietary choices against a range of physical evaluations, including cognitive function, blood metabolic biomarkers, brain imaging, and genetics.

The food preferences of each participant were collected via an online questionnaire, which the team categorised into 10 groups (eg, alcohol, fruits and meats).

A balanced diet was associated with better mental health, superior cognitive functions and even higher amounts of grey matter in the brain – linked to intelligence – compared with those with a less varied diet.

The study also highlighted the need for gradual dietary modifications, particularly for individuals accustomed to highly palatable but nutritionally deficient foods. By slowly reducing sugar and fat intake over time, individuals may find themselves naturally gravitating towards healthier food choices.

Genetic factors may also contribute to the association between diet and brain health, the scientists believe, showing how a combination of genetic predispositions and lifestyle choices shape wellbeing.

Lead Author Professor Jianfeng Feng, University of Warwick, emphasised the importance of establishing healthy food preferences early in life. He said: “Developing a healthy balanced diet from an early age is crucial for healthy growth. To foster the development of a healthy balanced diet, both families and schools should offer a diverse range of nutritious meals and cultivate an environment that supports their physical and mental health.”

Source: University of Warwick

Social Media can Influence Young People to Eat More Healthily

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Researchers from Aston University have found that people following healthy eating accounts on social media for as little as two weeks ate more fruit and vegetables and less junk food.

Previous research has shown that positive social norms about fruit and vegetables increases individuals’ consumption. The research team sought to investigate whether positive representation of healthier food on social media would have the same effect. The research was led by Dr Lily Hawkins, whose PhD study it was, supervised by Dr Jason Thomas and Professor Claire Farrow in the School of Psychology.

The researchers recruited 52 volunteers, all social media users, with a mean age of 22, and split them into two groups. Volunteers in the first group, known as the intervention group, were asked to follow healthy eating Instagram accounts in addition to their usual accounts. Volunteers in the second group, known as the control group, were asked to follow interior design accounts. The experiment lasted two weeks, and the volunteers recorded what they ate and drank during the time period.

Overall, participants following the healthy eating accounts ate an extra 1.4 portions of fruit and vegetables per day and 0.8 fewer energy dense items, such as high-calorie snacks and sugar-sweetened drinks, per day. This is a substantial improvement compared to previous educational and social media-based interventions attempting to improve diets.

Dr Thomas and the team believe affiliation is a key component of the change in eating behaviour. For example, the effect was more pronounced amongst participants who felt affiliated with other Instagram users.

The 2018 NHS Health Survey for England study showed that only 28% of the UK population consumed the recommended five portions of fruit and vegetables per day. Low consumption of such food is linked to heart disease, cancer and stroke, so identifying ways to encourage higher consumption is vital. Exposing people to positive social norms, using posters in canteens encouraging vegetable consumption, or in bars to discourage dangerous levels of drinking, have been shown to work. Social media is so prevalent now that the researchers believe it could be an ideal way to spread positive social norms around high fruit and vegetable consumption, particularly amongst younger people.

Dr Hawkins, who is now at the University of Exeter, said: “Our previous research has demonstrated that social norms on social media may nudge food consumption, but this pilot demonstrates that this translates to the real world. Of course, we would like to now understand whether this can be replicated in a larger, community sample.”

Source: Aston University

Dietary Intervention Trumps Drugs for IBS Treatment

Irritable bowel syndrome. Credit: Scientific Animations CC4.0

Dietary treatment is more effective than medications in irritable bowel syndrome (IBS), according to the results of a study conducted at the University of Gothenburg. With dietary adjustments, more than seven out of ten patients had significantly reduced symptoms.

Irritable bowel syndrome (IBS) is a common diagnosis that causes abdominal pain, gas and abdominal bloating, diarrhoea, and constipation, in various combinations and with varying degrees of severity.

Treatment often consists of dietary advice such as eating small and frequent meals and avoiding excessive intake of food triggers such as coffee, alcohol and fizzy drinks. Patients may also be given medications to improve specific symptoms, such as gas or constipation, diarrhoea, bloating or abdominal pain. Antidepressants are sometimes used to improve symptoms in IBS.

The current study, published in The Lancet Gastroenterology & Hepatology, compared three treatments: two dietary and one medication-based. The participants were adult patients with severe or moderate IBS symptoms at Sahlgrenska University Hospital in Gothenburg.

More symptom relief after dietary adjustment

The first group was given traditional IBS dietary advice, focusing on eating behaviour combined with low intake of fermentable carbohydrates (FODMAPs). These include products with lactose, legumes, onions, and grains, which ferment in the colon and can cause pain in IBS.

The second group received a dietary treatment low in carbohydrates and proportionally high in protein and fat. In the third group, the best possible medication was given based on the patient’s most troublesome IBS symptoms.

Each group included around 100 participants in four-week treatment periods. Treatment response was measure with an established IBS symptom scoring scale.

Of those who received traditional IBS dietary advice and low content of FODMAPs, 76% had significantly reduced symptoms. In the group receiving low carbohydrates and high protein and fat, the proportion was 71%, and in the medication group 58%.

All groups reported significantly better quality of life, less physical symptoms and less symptoms of anxiety and depression.

The importance of personalisation

At a six-month follow-up, when participants in the dietary groups had partially returned to their previous eating habits, a large proportion still had clinically significant symptom relief; 68% in the traditional dietary advice and low FODMAP group, and 60% in the low-carbohydrate diet group.

The study was led by Sanna Nybacka, Researcher and Dietician, Stine Störsrud, Associate Professor, and Magnus Simrén, Professor and Senior Consultant, all at Sahlgrenska Academy, University of Gothenburg.

“With this study, we can show that diet plays a central role in the treatment of IBS, but that there are several alternative treatments that are effective,” says Sanna Nybacka.

“We need more knowledge about how to best personalise the treatment of IBS in the future and we will further investigate whether there are certain factors that can predict whether individuals will respond better to different treatment options,” she concludes.

Source: University of Gothenburg

Giving Fizzy Drinks to Toddlers Increases Adult Obesity Risk

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Consuming sugar-sweetened drinks in the first few years of childhood can be linked to poor diet patterns that increase the risk of obesity in later life, according to a new study by the School of Psychology at Swansea University.

Published in the European Journal of Clinical Nutrition, the study tracked the influence of diet on 14 000 British children from birth to adulthood and is believed to be the longest of its kind ever reported.

Using the Avon Longitudinal Study of Parents and Children, the research team found:

  • Children who drank fizzy drinks such as cola or sugar-sweetened fruit cordials before the age of two gained more weight when they were 24 years old. Girls who had pure fruit juice gained less weight, while the weight of boys remained the same.
  • At three years of age, toddlers who drank cola consumed more calories, fat, protein, and sugar but less fibre. In contrast, those given pure apple juice consumed less fat and sugar but higher amounts of fibre.

The study also highlighted corresponding differences in food choices.

Children who consumed pure apple juice often followed a diet with more fish, fruit, green vegetables, and salad, whereas those drinking cola ate more burgers, sausages, pizza, french fries, meat, chocolate, and sweets.

Additionally, the team discovered a link between sugar-sweetened drinks and social deprivation, with children from affluent backgrounds more likely to have access to pure fruit juice.

Lead researcher Professor David Benton said: “The early diet establishes a food pattern that influences, throughout life, whether weight increases. The important challenge is to ensure that a child develops a good dietary habit: one that offers less fat and sugar, although pure fruit juice, one of your five a day, adds vitamin C, potassium, folate, and plant polyphenols.”

Dr Hayley Young added: “Obesity is a serious health concern, one that increases the risk of many other conditions. Our study shows that the dietary causes of adult obesity begin in early childhood and that if we are to control it, more attention needs to be given to our diet in the first years of life.”

Source: Swansea University

Obese and Overweight Children at Risk of Iron Deficiency

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Children and young people who are overweight or obese are at significantly higher risk of iron deficiency, according to a study by nutritional scientists at the University of Leeds.

Researchers from the School of Food Science and Nutrition examined thousands of medical studies from 44 countries involving people under the age of 25 where levels of iron and other vitamins and minerals had been recorded alongside weight. They found that iron deficiency was associated with both underweight and overweight children and adolescents.

By contrast, zinc and vitamin A deficiencies were only observed in children who were undernourished, leading researchers to conclude that iron deficiency in overweight children is probably due to inflammation disrupting the mechanisms that regulate iron absorption.

The results of the research appear in the journal BMJ Global Health.

Iron deficiency in children has a negative effect on brain function, including attention, concentration and memory, and can increase the risk of conditions, such as autism and ADHD.

It is already recognised as a problem in adults living with obesity, but this research is the first to look at the association in children.

Lead author Xiaomian Tan, a Doctoral Researcher in the University of Leeds’ School of Food Science and Nutrition said: “The relationship between undernutrition and critical micronutrients for childhood growth and development is well established, but less is known about the risk of deficiencies in iron, vitamin A and zinc in children and adolescents who are overweight or obese, making this a hidden form of malnutrition.

“Our research is hugely important given the high prevalence of obesity in children. We hope it will lead to increased recognition of the problem by healthcare practitioners and improvements in clinical practice and care.”

Hidden hunger

Historically the problem has been linked to malnutrition and is a particular concern for lower- and middle-income countries where hunger may be the leading cause of mortality for young children.

Increasingly though it is being recognised that vitamin and mineral deficiencies can also occur in people who are overweight and obese and who have a nutrient-poor but energy-dense diet, something which has been described as ‘hidden hunger’.

In high-income countries it is associated with ultra-processed foods that are high in fat, sugar, salt, and energy but in lower- and middle-income countries obesity is often associated with poverty and monotonous diets with limited choices of staples such as corn, wheat, rice, and potatoes.

Many developing countries are now facing a double burden of malnutrition alongside overnutrition due to the rapid increase in the global prevalence of obesity in recent decades, especially in children aged between five and 19.

Undernutrition versus overnutrition

The research also highlights differences in focus between higher income countries and developing nations, with most studies in Africa and Asia focusing on undernutrition and those from North America and Europe focusing entirely on overnutrition.

The researchers say this is particularly concerning as both Africa and Asia are experiencing the highest double burden of malnutrition due to economic growth and the transition to a western-style high-sugar, high-fat diet.

Between the years 2000 and 2017, the number of overweight children under the age of five in Africa increased from 6.6 to 9.7 million, and in Asia that figure rose from 13.9 to 17.5 million. At the same time, there was an increase in the number of stunted children under 5, from 50.6 to 58.7 million in Africa.

Research supervisor Bernadette Moore, Professor of Nutritional Sciences in Leeds’ School of Food Science and Nutrition, said: “These stark figures underscore the fact that the investigation of micronutrient deficiencies in relation to the double burden of malnutrition remains critically important for child health.

“By the age of 11 here in the UK, one in three children are living with overweight or obesity, and our data suggests that even in overweight children inflammation leading to iron deficiency can be an issue.

“Iron status may be the canary in the coalmine, but the real issue is that prolonged inflammation leads to heart disease, diabetes and fatty liver.”

Increasing physical activity and improving diet have been shown to reduce inflammation and improve iron status in children and the researchers are now calling for further studies into the effectiveness of these interventions.

They also believe that more research is needed into micronutrient deficiencies and the double burden of malnutrition and overnutrition in countries where there are currently gaps in data.

Source: University of Leeds

Eggs are not the Cholesterol Menace They were Thought to be

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Many people hesitate to eat eggs amid concerns that they may raise cholesterol levels, with negative cardiovascular consequences. However, results from a prospective, controlled trial presented at the American College of Cardiology’s Annual Scientific Session show that over a four-month period cholesterol levels and other cardiovascular markers were similar among people who ate fortified eggs most days of the week compared with a non-egg eating control group.

A total of 140 patients with or at high risk for cardiovascular disease were enrolled in the PROSPERITY trial, which aimed to assess the effects of eating 12 or more fortified eggs a week versus a non-egg diet (consuming less than two eggs a week) on HDL- and LDL-cholesterol, as well as other key markers of cardiovascular health over a four-month study period.

“We know that cardiovascular disease is, to some extent, mediated through risk factors like high blood pressure, high cholesterol and increased BMI and diabetes. Dietary patterns and habits can have a notable influence on these and there’s been a lot of conflicting information about whether or not eggs are safe to eat, especially for people who have or are at risk for heart disease,” said Nina Nouhravesh, MD, a research fellow at the Duke Clinical Research Institute in Durham, North Carolina, and the study’s lead author. “This is a small study, but it gives us reassurance that eating fortified eggs is OK with regard to lipid effects over four months, even among a more high-risk population.”

Eggs are a common and relatively inexpensive source of protein and dietary cholesterol. Nouhravesh and her team wanted to look specifically at fortified eggs as they contain less saturated fat and additional vitamins and minerals, such as iodine, vitamin D, selenium, vitamin B2, 5 and 12, and omega-3 fatty acids.

For this study, patients were randomly assigned to eat 12 fortified eggs a week (cooked in whatever manner they chose) or to eat fewer than two eggs of any kind (fortified or not) per week.  All patients were 50 years of age or older (the average age was 66 years), half were female and 27% were Black. All patients had experienced one prior cardiovascular event or had two cardiovascular risk factors, such as high blood pressure, high cholesterol, increased BMI or diabetes. The co-primary endpoint was LDL and HDL cholesterol at four months. Secondary endpoints included lipid, cardiometabolic and inflammatory biomarkers and levels of vitamin and minerals. 

Patients had in-person clinic visits at the start of the study and visits at one and four months to take vital signs and have bloodwork done. Phone check-ins occurred at two and three months and patients in the fortified egg group were asked about their weekly egg consumption. Those with low adherence were provided additional education materials.

Results showed a -0.64mg/dL and a -3.14mg/dL reduction in HDL-cholesterol and LDL cholesterol, respectively, in the fortified egg group. While these differences weren’t statistically significant, the researchers said the differences suggest that eating 12 fortified eggs each week had no adverse effect on blood cholesterol. In terms of secondary endpoints, researchers observed a numerical reduction in total cholesterol, LDL particle number, another lipid biomarker called apoB, high-sensitivity troponin (a marker of heart damage), and insulin resistance scores in the fortified egg group, while vitamin B increased.

“While this is a neutral study, we did not observe adverse effects on biomarkers of cardiovascular health and there were signals of potential benefits of eating fortified eggs that warrant further investigation in larger studies as they are more hypothesis generating here,” Nouhravesh said, explaining that subgroup analyses revealed numerical increases in HDL cholesterol and reductions in LDL cholesterol in patients 65 years or older and those with diabetes in the fortified egg group compared with those eating fewer than two eggs.

So why have eggs gotten a bad rap? Some of the confusion stems from the fact that egg yolks contain cholesterol. Experts said a more important consideration, especially in the context of these findings, might be what people are eating alongside their eggs, such as buttered toast, bacon and other processed meats, which are not heart healthy choices. As always, Nouhravesh said it’s a good idea for people with heart disease to talk with their doctor about a heart healthy diet.

This single-centre study is limited by its small size and reliance on patients’ self-reporting of their egg consumption and other dietary patterns. It was also an unblinded study, which means patients knew what study group they were in, which can influence their health behaviours.

The study was funded by Eggland’s Best.

Source: American College of Cardiology

Can a Ketogenic Diet Treat Serious Mental Illnesses?

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Antipsychotic medications for serious mental illness like schizophrenia or bipolar disorder often causes metabolic side effects such as insulin resistance and obesity, leading some patients to discontinue the treatment.

Now, a pilot study led by Stanford Medicine researchers has found that a ketogenic diet not only restores metabolic health in these patients as they continue their medications, but it further improves their psychiatric conditions. The results, published in Psychiatry Research, suggest that a dietary intervention can be a powerful aid in treating mental illness.

“It’s very promising and very encouraging that you can take back control of your illness in some way, aside from the usual standard of care,” said Shebani Sethi, MD, associate professor of psychiatry and behavioral sciences and the first author of the new paper.

The senior author of the paper is Laura Saslow, PhD, associate professor of health behavior and biological sciences at the University of Michigan.

Making the connection

Sethi, who is board certified in obesity and psychiatry, remembers when she first noticed the connection. As a medical student working in an obesity clinic, she saw a patient with treatment-resistant schizophrenia whose auditory hallucinations quieted on a ketogenic diet.

That prompted her to dig into the medical literature. There were only a few, decades-old case reports on using the ketogenic diet to treat schizophrenia, but there was a long track record of success in using ketogenic diets to treat epileptic seizures.

“The ketogenic diet has been proven to be effective for treatment-resistant epileptic seizures by reducing the excitability of neurons in the brain,” Sethi said. “We thought it would be worth exploring this treatment in psychiatric conditions.”

A few years later, Sethi coined the term metabolic psychiatry, a new field that approaches mental health from an energy conversion perspective.

Meat and vegetables

In the four-month pilot trial, Sethi’s team followed 21 adult participants who were diagnosed with schizophrenia or bipolar disorder, taking antipsychotic medications, and had a metabolic abnormality – such as weight gain, insulin resistance, hypertriglyceridaemia, dyslipidaemia or impaired glucose tolerance. The participants were instructed to follow a ketogenic diet, with approximately 10% of the calories from carbohydrates, 30% from protein and 60% from fat. They were not told to count calories.

“The focus of eating is on whole non-processed foods including protein and non-starchy vegetables, and not restricting fats,” said Sethi, who shared keto-friendly meal ideas with the participants. They were also given keto cookbooks and access to a health coach.

The research team tracked how well the participants followed the diet through weekly measures of blood ketone levels, which are produced when the body breaks down fat instead of glucose for energy. By the end of the trial, 14 patients had been fully adherent, six were semi-adherent and only one was non-adherent.

Physical and mental improvement

The participants underwent a variety of psychiatric and metabolic assessments throughout the trial.

Before the trial, 29% of the participants met the criteria for metabolic syndrome, defined as having at least three of five conditions: abdominal obesity, elevated triglycerides, low HDL cholesterol, elevated blood pressure and elevated fasting glucose levels. After four months on a ketogenic diet, none of the participants had metabolic syndrome.

On average, the participants lost 10% of their body weight; reduced their waist circumference by 11% percent; and had lower blood pressure, body mass index, triglycerides, blood sugar levels and insulin resistance.

“We’re seeing huge changes,” Sethi said. “Even if you’re on antipsychotic drugs, we can still reverse the obesity, the metabolic syndrome, the insulin resistance. I think that’s very encouraging for patients.”

The psychiatric benefits were also striking. On average, the participants improved 31% on a psychiatrist rating of mental illness known as the clinical global impressions scale, with three-quarters of the group showing clinically meaningful improvement. Overall, the participants also reported better sleep and greater life satisfaction.

“The participants reported improvements in their energy, sleep, mood and quality of life,” Sethi said. “They feel healthier and more hopeful.”

The researchers were impressed that most of the participants stuck with the diet. “We saw more benefit with the adherent group compared with the semi-adherent group, indicating a potential dose-response relationship,” Sethi said.

Alternative fuel for the brain

There is increasing evidence that psychiatric diseases such as schizophrenia and bipolar disorder stem from metabolic deficits in the brain, which affect the excitability of neurons, Sethi said. The researchers hypothesise that just as a ketogenic diet improves the rest of the body’s metabolism, it also improves the brain’s metabolism.

“Anything that improves metabolic health in general is probably going to improve brain health anyway,” Sethi said. “But the ketogenic diet can provide ketones as an alternative fuel to glucose for a brain with energy dysfunction.”

Likely there are multiple mechanisms at work, she added, and the main purpose of the small pilot trial is to help researchers detect signals that will guide the design of larger, more robust studies.

As a physician, Sethi cares for many patients with both serious mental illness and obesity or metabolic syndrome, but few studies have focused on this undertreated population. She is founder and director of the metabolic psychiatry clinic at Stanford Medicine.

“Many of my patients suffer from both illnesses, so my desire was to see if metabolic interventions could help them,” she said. “They are seeking more help. They are looking to just feel better.”

Source: Stanford Medicine

Do Sweeteners Increase Appetite? New Randomised Controlled Trial Says No

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Replacing sugar with artificial and natural sweeteners in foods has been the subject of a great deal of controversy, due to conflicting reports about their potential to increase appetite. But according to a significant new study published in eBioMedicine, it does not in fact make people hungrier as is often held – and also helps to reduce blood sugar levels.

Previous studies into whether sugar replacement with sweeteners increase appetite have been carried out but did not provide robust evidence. But the researchers say that their study, which meets the gold standard level of proof in scientific investigation, provides very strong evidence that sweeteners and sweetness enhancers do not negatively impact appetite and are beneficial for reducing sugar intake.

The double blind randomised controlled trial found that consuming food containing sweeteners produced a similar reduction in appetite sensations and appetite-related hormone responses as sugary foods. Additionally, it was found to provide some benefits such as lowering blood sugar, which may be particularly important in people at risk of developing type 2 diabetes.

The trial was led by the University of Leeds in collaboration with the The Rhône-Alpes Research Center for Human Nutrition. It is the latest study to be published by the SWEET consortium of 29 European research, consumer and industry partners which is working to develop and review evidence on long term benefits and potential risks involved in switching over to sweeteners and sweetness enhancers in the context of public health and safety, obesity, and sustainability. It was funded by Horizon Europe.

Lead author Catherine Gibbons, Associate Professor in the University of Leeds’ School of Psychology, said: “Reducing sugar consumption has become a key public health target in the fight to reduce the rising burden of obesity-related metabolic diseases such as type 2 diabetes.

“Simply restricting sugar from foods without substitution may negatively impact its taste or increase sweet cravings, resulting in difficulties sticking to a low-sugar diet. Replacing sugars with sweeteners and sweetness enhancers in food products is one of the most widely used dietary and food manufacturing strategies to reduce sugar intake and improve the nutritional profile of commercial foods and beverages.”

Principal investigator Graham Finlayson, Professor of Psychobiology in the University of Leeds’ School of Psychology, said: “The use of sweeteners and sweetness enhancers has received a lot of negative attention, including high profile publications linking their consumption with impaired glycaemic response, toxicological damage to DNA and increased risk of heart attack and stroke. These reports contribute to the current befuddlement concerning the safety of sweeteners and sweetness enhancers among the general public and especially people at risk of metabolic diseases.

“Our study provides crucial evidence supporting the day-to-day use of sweeteners and sweetness enhancers for body weight and blood sugar control.”

Until now, virtually all studies of the effects of sweeteners and sweetness enhancers on appetite and glycaemia have been conducted using beverages as the vehicle. Few studies include volunteers with overweight or obesity and few have included volunteers of both sexes.

Most studies have only compared a single sweetener, mostly aspartame, with a control, and very few studies have examined the effect of repeated daily intake of a known sweetener or sweetness enhancer in the normal diet.

The study, which is the first of its kind, looked at the effects of consuming biscuits containing either sugar or two types of food sweetener: natural sugar substitute Stevia, or artificial sweetener Neotame on 53 adult men and women with overweight or obesity. Participants were all aged 18 to 60, with overweight or obesity.

The trial consisted of three two-week consumption periods, where participants consumed biscuits with either fruit filling containing sugar; natural sugar substitute Stevia, or artificial sweetener Neotame, each separated by a break of 14–21 days. Day 1 and day 14 of the consumption periods took place in the lab.

Participants were instructed to arrive in the lab after an overnight fast, a blood sample was taken to establish baseline levels of glucose, insulin and appetite-related hormones. They were also asked to rate their appetite and food preferences.

After consuming the biscuits, they were asked to rate how full they felt over several hours. Glucose and insulin levels were measured, as were ghrelin, glucagon-like peptide 1 and pancreatic polypeptide – hormones associated with the consumption of food.

The results from the two sweetener types showed no differences in appetite or endocrine responses compared to sugar, but insulin levels measured over two hours after eating were reduced, as were blood sugar levels.

Source: University of Leeds