Category: Diet and Nutrition

Categories : Diet and NutritionTags :

Are Ultra-processed Foods the New ‘Silent Killer’?

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Photo by Patrick Fore on Unsplash

Nowadays, ultra-processed foods are packed with a bewildering range of additives: there are common ones like oil, fat, and sugar. There are also emulsifiers such as carrageenan, mono- and diglycerides, carboxymethylcellulose, polysorbate and soy lecithin. These continue to strip food of healthy nutrients while introducing other ingredients that could also be detrimental to human health.

Hundreds of novel ingredients never encountered by human physiology are now found in nearly 60% of the average adult’s diet and nearly 70% of children’s diets in the United States.

While obesity and lack of physical activity are well recognised contributors to avoidable morbidity and mortality, another emerging hazard is the unprecedented consumption of these ultra-processed foods in the standard American diet. This may be the new “silent” killer, as was unrecognised hypertension in previous decades.

Physicians from Florida Atlantic University’s Schmidt College of Medicine explored this hypothesis and provide important insights to health care providers in a battle where the entertainment industry, the food industry and public policy do not align with their patients’ needs. Their findings are published in a commentary in The American Journal of Medicine.

First generation of doctors to see a reduction in life expectancy

“Those of us practicing medicine in the US today find ourselves in an ignominious and unique position – we are the first cohort of health care professionals to have presided over a decline in life expectancy in 100 years,” said Dawn H. Sherling, MD, corresponding author, associate program director for the internal medicine residency and an associate professor of medicine, FAU Schmidt College of Medicine. “Our life expectancy is lower than other economically comparable countries. When we look at increasing rates of non-communicable diseases in less developed nations, we can see a tracking of this increase along with increasing consumption of ultra-processed foods in their diets.”

Although professional organizations such as the American College of Cardiology cautions patients to “choose minimally processed foods instead of ultra-processed foods” in their 2021 dietary guidelines, there is a caveat that “there is no commonly accepted definition for ultra-processed foods, and some healthy foods may exist within the ultra-processed food category.”

“When the components of a food are contained within a natural, whole food matrix, they are digested more slowly and more inefficiently, resulting in less calorie extraction, lower glycaemic loads in general, and lower rise in triglyceride-rich lipoproteins after eating, which could result in atherosclerotic plaque,” said Allison H. Ferris, MD, senior author, an associate professor and chair, Department of Medicine, and director of the internal medicine residency program, FAU Schmidt College of Medicine. “Therefore, even if the troublesome additives were removed from the ultra-processed food, there would still be concern for an over-consumption of these products possibly leading to obesity, diabetes and heart disease.”

The authors add that public health organisations are increasingly making use of the NOVA classification system, which divides foods into four categories – whole foods, culinary ingredients (items like butter, oil and salt), traditionally processed foods (such as bread and yogurt made with few ingredients), and ultra-processed foods – or those foods that are industrially made and use ingredients not normally found in a domestic kitchen.

According to the authors, one plausible mechanism to explain the hazards is that ultra-processed foods contain emulsifiers and other additives that the mammalian gastrointestinal tract mostly does not digest. They may act as a food source for our microbiota, and as such may be creating a dysbiotic microbiome that can, in the right host, promote disease.

“Additives, such as maltodextrin, may promote a mucous layer that is friendly to certain species of bacteria that are found in greater abundance in patients with inflammatory bowel disease,” said Sherling. “When the mucous layer is not properly maintained, the epithelial cell layer may become vulnerable to injury, as has been shown in feeding studies using carrageenan in humans and other studies in mice models, using polysorbate-80 and cellulose gum, triggering immunologic responses in the host.”

Food companies as powerful as the 20th century’s tobacco companies

The authors add that there have been marked increases in colorectal cancer in the US, especially among younger adults. They opine that increased ultra-processed food consumption may be a contributor as well as to several other gastrointestinal diseases.

“Whether ultra-processed foods contribute to our currently rising rates of non-communicable disease requires direct testing in analytic studies designed a priori to do so,” said Charles H. Hennekens, MD, FACPM, co-author, the First Sir Richard Doll Professor of Medicine and senior academic advisor, FAU Schmidt College of Medicine. “In the meantime, we believe it is incumbent upon all health care professionals to discuss the benefits of increasing consumption of whole foods and reducing consumption of ultra-processed foods with their patients.”

The authors also opine that just as the dangers of tobacco began to emerge during the middle of the prior century, decades passed before the preponderance of the evidence and the efforts of forward-thinking health officials prompted policy change to discourage the use of cigarettes. They say there is likely to be a similar path for ultra-processed foods.

“The multinational companies that produce ultra-processed foods are just as, if not more, powerful than tobacco companies were in the last century, and it is unlikely that governments will be able to move quickly on policies that will promote whole foods and discourage the consumption of ultra-processed foods,” said Sherling. “Importantly, health care providers also should remain cognizant of the difficulties that many of our patients have in being able to afford and find healthier options, which calls for a broader public health response.”

Source: Florida Atlantic University

Categories : Cardiovascular Disease Diet and NutritionTags :

Excessive Protein Consumption Increases Atherosclerosis Risk

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Cardiovascular pitfalls to increasing protein intake discovered

Image by Scientific Animations, CC4.0

University of Pittsburgh School of Medicine researchers discovered a molecular mechanism by which excessive dietary protein could increase atherosclerosis risk. The study, published in Nature Metabolism, combined small human trials with in vitro human and mouse cell experiments.

It showed that consuming over 22% of dietary calories from protein can lead to increased activation of immune cells that play a role in atherosclerotic plaque formation, driving the disease risk.

Furthermore, the scientists showed that one amino acid, leucine, seems to have a disproportionate role in driving the pathological pathways linked to atherosclerosis, or stiff, hardened arteries.

“Our study shows that dialling up your protein intake in pursuit of better metabolic health is not a panacea. You could be doing real damage to your arteries,” said senior and co-corresponding author Babak Razani, MD, PhD, professor of cardiology at Pitt.

“Our hope is that this research starts a conversation about ways of modifying diets in a precise manner that can influence body function at a molecular level and dampen disease risks.”

According to a survey of an average American diet over the last decade, Americans generally consume a lot of protein, mostly from animal sources.

Further, nearly a quarter of the population receives over 22% of all daily calories from protein alone.

That trend is likely driven by the popular idea that dietary protein is essential to healthy living, says Razani.

But his and other groups have shown that overreliance on protein may not be such a good thing for long-term health.

Following their 2020 research, in which Razani’s laboratory first showed that excess dietary protein increases atherosclerosis risk in mice, his next study in collaboration with Bettina Mittendorfer, PhD, a metabolism expert at the University of Missouri, Columbia, delved deeper into the potential mechanism and its relevance to the human body.

To arrive at the answer, Razani’s laboratory, led by first-authors Xiangyu Zhang, Ph.D., and Divya Kapoor, M.D., teamed up with Mittendorfer’s group to combine their expertise in cellular biology and metabolism and perform a series of experiments across various models, from cells to mice to humans.

“We have shown in our mechanistic studies that amino acids, which are really the building blocks of the protein, can trigger disease through specific signaling mechanisms and then also alter the metabolism of these cells,” Mittendorfer said.

“For instance, small immune cells in the vasculature called macrophages can trigger the development of atherosclerosis.”

Based on initial experiments in healthy human subjects to determine the timeline of immune cell activation following ingestion of protein-enriched meals, the researchers simulated similar conditions in mice and in human macrophages, immune cells that are shown to be particularly sensitive to amino acids derived from protein.

Their work showed that consuming more than 22% of daily dietary calories through protein can negatively affect macrophages that are responsible for clearing out cellular debris, leading to the accumulation of a “graveyard” of those cells inside the vessel walls and worsening of atherosclerotic plaques overtime.

Interestingly, the analysis of circulating amino acids showed that leucine, an amino acid enriched in animal-derived foods like beef, eggs and milk, is primarily responsible for abnormal macrophage activation and atherosclerosis risk, suggesting a potential avenue for further research on personalized diet modification, or “precision nutrition.”

Razani is careful to note that many questions remain to be answered, mainly: What happens when a person consumes between 15% of daily calories from protein as recommended by the USDA and 22% of daily calories from protein, and if there is a ‘sweet spot’ for maximising the benefits of protein (such as muscle gain) while avoiding kick-starting a molecular cascade of damaging events leading to cardiovascular disease.

The findings are particularly relevant in hospital settings, where nutritionists often recommend protein-rich foods for the sickest patients to preserve muscle mass and strength.

“Perhaps blindly increasing protein load is wrong,” Razani said.

“Instead, it’s important to look at the diet as a whole and suggest balanced meals that won’t inadvertently exacerbate cardiovascular conditions, especially in people at risk of heart disease and vessel disorders.”

Razani also notes that these findings suggest differences in leucine levels between diets enriched in plant and animal protein might explain the differences in their effect on cardiovascular and metabolic health.

“The potential for this type of mechanistic research to inform future dietary guidelines is quite exciting,” he said.

Source: University of Pittsburgh

Categories : Diet and Nutrition Immune SystemTags :

Switching to Vegan or Keto Diets Impacts Immune System

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Researchers at the National Institutes of Health observed rapid and distinct immune system changes in a small study of people who switched to a vegan or a ketogenic (“keto”) diet. They found that the vegan diet prompted responses linked to innate immunity while the keto diet prompted responses associated with adaptive immunity. Metabolic changes and shifts in the participants’ microbiomes were also observed. More research is needed to determine if these changes are beneficial or detrimental and what effect they could have on nutritional interventions for diseases such as cancer or inflammatory conditions.

Scientific understanding of how different diets impact the human immune system and microbiome is limited. Therapeutic nutritional interventions, which involve changing the diet to improve health, are not well understood, and few studies have directly compared the effects of more than one diet. The keto diet is a low-carbohydrate diet that is generally high in fat. The vegan diet eliminates animal products and tends to be high in fibre and low in fat.

The study was conducted by researchers from the NIH’s National Institute of Allergy and Infectious Diseases (NIAID) and National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) at the Metabolic Clinical Research Unit in the NIH Clinical Center.

The 20 participants were diverse with respect to ethnicity, race, gender, body mass index (BMI), and age. Participants sequentially ate vegan and keto diets for two weeks, in random order. Each person ate as much as desired of one diet (vegan or keto) for two weeks, followed by as much as desired of the other diet for two weeks. People on the vegan diet, which contained about 10% fat and 75% carbohydrates, chose to consume fewer calories than those on the keto diet, which contained about 76% fat and 10% carbohydrates. Throughout the study period, blood, urine, and stool were collected for analysis.

The effects of the diets were examined using a “multi-omics” approach that analysed multiple data sets to assess the body’s biochemical, cellular, metabolic, and immune responses, as well as changes to the microbiome.

Participants remained on site for the entire month-long study, allowing for careful control of the dietary interventions. Switching exclusively to the study diets caused notable changes in all participants.

The vegan diet significantly impacted pathways linked to the innate immune system, including antiviral responses. On the other hand, the keto diet led to significant increases in biochemical and cellular processes linked to adaptive immunity, such as pathways associated with T and B cells.

The keto diet affected levels of more proteins in the blood plasma than the vegan diet, as well as proteins from a wider range of tissues, such as the blood, brain and bone marrow. The vegan diet promoted more red blood cell-linked pathways, including those involved in heme metabolism, which could be due to the higher iron content of this diet.

Additionally, both diets produced changes in the microbiomes of the participants, causing shifts in the abundance of gut bacterial species that previously had been linked to the diets.

The keto diet was associated with changes in amino acid metabolism – an increase in human metabolic pathways for the production and degradation of amino acids and a reduction in microbial pathways for these processes – which might reflect the higher amounts of protein consumed by people on this diet.

The distinct metabolic and immune system changes caused by the two diets were observed despite the diversity of the participants, which shows that dietary changes consistently affect widespread and interconnected pathways in the body. More study is needed to examine how these nutritional interventions affect specific components of the immune system. According to the authors, the results of this study demonstrate that the immune system responds surprisingly rapidly to nutritional interventions. The authors suggest that it may be possible to tailor diets to prevent disease or complement disease treatments, such as by slowing processes associated with cancer or neurodegenerative disorders.

Source: NIH/National Institute of Allergy and Infectious Diseases

Categories : Diet and NutritionTags :

People with Gluten Sensitivity have Negative Effects – Even When Eating a Placebo

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Photo by Mariana Kurnyk

Symptoms of gluten sensitivity are partly to do with people’s expectations, if celiac disease and wheat allergy have been excluded as causes. Recent research at the universities of Maastricht and Leeds shows that the expectation that gluten causes gastrointestinal complaints plays a crucial role in whether or not people experience these symptoms. These results, published in The Lancet Gastroenterology and Hepatology, indicate a direct involvement of the interaction between the brain and the intestines – the ‘gut-brain axis’ – in the experience of complaints after ingesting gluten.

Fear of gluten

A growing number of people are reducing their gluten intake due to self-reported digestive complaints, despite the fact that celiac disease and wheat allergy have been ruled out. The cause of their symptoms is often unclear. The researchers therefore wanted to investigate the effects of expectations on symptoms experienced after gluten intake. More than 80 subjects with self-reported gluten sensitivity took part in a psychological study and were divided into four groups. The results were unequivocal: people who thought they were eating food containing gluten reported more symptoms, while those who thought their food was gluten-free reported fewer symptoms.

In reality, the food given to half of each group contained gluten, while for the other half it was gluten-free. In all of the groups people’s expectations played a prominent role in whether or not they reported symptoms after eating. “In our research, we see a so-called nocebo effect when people eat gluten,” says researcher Marlijne de Graaf. “If people expect gluten to produce negative effects, they experience symptoms, even if it turns out afterwards that they weren’t actually eating gluten. Although the cause is partly ‘in the mind’, this doesn’t mean that the symptoms are not real.”

Gut-brain axis

The results of this study indicate a clear involvement of the interaction between the brain and the intestines in gluten sensitivity, a subject on which knowledge is as yet limited. The researchers therefore now want to concentrate on unravelling the mechanisms that determine the importance of expectation and exposure along the gut-brain axis. ‘Due to the influence of interactions between the brain and the intestines, people can genuinely experience symptoms such as stomach ache, bloating or diarrhoea after eating gluten,’ says Daisy Jonkers, professor of Intestinal Health at Maastricht University. ‘But the cause of these complaints is not only eating gluten, so a gluten-free diet isn’t the only solution.’

To treat this problem, the researchers want to conduct further studies on the influence of the brain on the development of bowel complaints. ‘For example, we’d like to know exactly which areas in the brain are involved,” says Jonkers, “and we also want to find out what substances play a role in the communication between the brain and the gut, and whether people might respond differently to them. It’s also quite possible that some people can’t tolerate wheat products because of substances in wheat other than gluten, and that there is indeed something in wheat that can lead to overstimulation of the immune system, for example, or excessive production of gas by the gut flora. This is also something we’d like to investigate.”

Source: Maastricht University

Categories : Ageing Diet and NutritionTags :

Meat Builds Muscle Proteins Better than Equivalent Vegan Dishes

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Older adults require more protein but eat less than younger people, making it a challenge for them to maintain muscle mass. Eating a meal with meat ensures that muscle proteins are built faster than a vegan meal with the same amount of protein. This study, published in The Journal of Nutrition, was the first to compare the speed at which muscle proteins are being made after eating a complete meal with animal or plant proteins.

Every two to three months the proteins in human muscle are completely renewed. In order to make muscle proteins, we need protein from food, for example from animal sources such as meat, cheese and yoghurt, or from plant products such as beans, nuts and soymilk. Previous research on protein powders showed that animal proteins have better muscle-building properties than plant proteins. “But in reality, we do not get our proteins in powder form, but through complete meals,” says study author and PhD student Philippe Pinckaers. “Those meals contain different types of protein and other nutrients such as fibres, fats and carbohydrates. These nutrients affect how proteins are released from the diet and influences the making of muscle proteins.”

To investigate how muscles respond after eating a complete meal, Pinckaers asked 16 participants aged over 65 to come to the lab twice for a dinner meal.

Dining out in the lab

On one day, the participants sat down to a meal with quinoa with chickpeas, broad beans, soy beans and soy sauce was on the menu, while on the other day the menu consisted of a beef tartlet, potatoes, green beans, apple sauce and herb butter. Both meals had similar amounts of protein, fat, carbohydrates and calories. Prior to the meals, participants were administered an infusion of special amino acids.

“The amino acids administered via the infusion were marked, as it were with a flag,” Pinckaers explains. “We took small pieces of muscle tissue from the participants and were able to measure the amount of ‘flags’ in them. If more flags are measured, it means that muscle proteins are built up faster, which is beneficial for muscles. In this way, we found that after eating a meal with animal protein, muscle protein was built up faster than after eating a vegan meal. This means that a vegan meal does not have the same capacity to make muscle proteins as a meal that includes animal proteins.” This difference arises partly because plant-based foods are harder to digest, and because they naturally contain fewer essential amino acids.

Context is key  

The results do not mean that everyone should eat meat or other animal products, clarifies professor of exercise science and lead researcher Luc van Loon. “Healthy people can very well compensate for the lower quality of plant proteins by eating more of them.” For elderly or frail patients it is a bit more complicated. “Elderly people actually need more protein in order to reach the same level of muscle protein synthesis, when compared to young individuals. However, they actually eat less. Also, patients with reduced appetite or who do not exercise much, for example during hospitalisation, may have trouble consuming a sufficient amount of protein. For them, it is therefore important to choose protein sources that stimulate the making of muscle proteins as much as possible. The best sources in this situation would be proteins from animal products.”

Source: Maastricht University

Categories : Addiction Diet and NutritionTags :

Removing Largest Serving Sizes of Wine Decreases Alcohol Consumption, Study Finds

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When pubs, bars and restaurants in England removed their largest size of wine sold by the glass, consumers drank less alcohol

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Alcohol consumption is the fifth largest contributor to premature death and disease globally. Many cues in physical and economic environments influence alcohol consumption across populations. One proposed intervention to excessive alcohol consumption is reducing the size of servings of alcoholic drinks sold by the glass, but there has been no real-world evidence for the effectiveness of this.

In the new study, researchers asked 21 licensed premises in England to remove from their menus their largest serving of wine by the glass – usually 250mL – for four weeks. The researchers then tracked the total volume of wine, beer and cider sold by each establishment.

Over the course of the four weeks, the total volume of wine sold by the licensed premises decreased by 7.6%, and there was no overall increase in beer and cider sales. There was an increase in the sales of smaller servings of wine by the glass – generally 125mL and 175mL – but no impact on sales of wine by the bottle or beer or cider sales.

“This suggests that this is a promising intervention for decreasing alcohol consumption across populations, which merits consideration as part of alcohol licensing regulations,” the authors say.

Marteau adds, “Removing the largest serving size of wine by the glass in 21 licensed premises reduced the volume of wine sold, in keeping with the wealth of research showing smaller serving sizes reduce how much we eat. This could become a novel intervention to improve population health by reducing how much we drink.”

Categories : Ageing Diet and NutritionTags :

How Calorie Restriction Slows Aging in the Brain

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Restricting calories is known to improve health and increase lifespan, but much of how it does so remains a mystery, especially in regard to how it protects the brain. Now, scientists from the Buck Institute for Research on Aging have uncovered a role for a gene called OXR1 that is necessary for the lifespan extension seen with dietary restriction and is essential for healthy brain aging.

“When people restrict the amount of food that they eat, they typically think it might affect their digestive tract or fat buildup, but not necessarily about how it affects the brain,” said Kenneth Wilson, PhD, Buck postdoc and first author of the study, published in Nature Communications. “As it turns out, this is a gene that is important in the brain.”

The team additionally demonstrated a detailed cellular mechanism of how dietary restriction can delay aging and slow the progression of neurodegenerative diseases. The work, done in fruit flies and human cells, also identifies potential therapeutic targets to slow aging and age-related neurodegenerative diseases.

“We found a neuron-specific response that mediates the neuroprotection of dietary restriction,” said Buck Professor Pankaj Kapahi , PhD, co-senior author of the study. “Strategies such as intermittent fasting or caloric restriction, which limit nutrients, may enhance levels of this gene to mediate its protective effects.”

“The gene is an important brain resilience factor protecting against aging and neurological diseases,” said Buck Professor Lisa Ellerby, PhD, co-senior author of the study.

Understanding variability in response to dietary restriction

Members of the team have previously shown mechanisms that improve lifespan and healthspan with dietary restriction, but it was not clear why there is so much variability in response to reduced calories across individuals and different tissues. This project was started to understand why different people respond to diets in different ways.

The team began by scanning about 200 strains of flies with different genetic backgrounds. The flies were raised with two different diets, either with a normal diet or with dietary restriction, which was only 10% of normal nutrition. Researchers identified five genes which had specific variants that significantly affected longevity under dietary restriction. Of those, two had counterparts in human genetics.

The team chose one gene to explore thoroughly, called “mustard” (mtd) in fruit flies and “Oxidation Resistance 1” (OXR1) in humans and mice. The gene protects cells from oxidative damage, but the mechanism for how this gene functions was unclear. The loss of OXR1 in humans results in severe neurological defects and premature death. In mice, extra OXR1 improves survival in a model of amyotrophic lateral sclerosis (ALS).

The link between brain aging, neurodegeneration and lifespan

To figure out how a gene that is active in neurons affects overall lifespan, the team did a series of in-depth tests. They found that OXR1 affects a complex called the retromer, which is a set of proteins necessary for recycling cellular proteins and lipids. “The retromer is an important mechanism in neurons because it determines the fate of all proteins that are brought into the cell,” said Wilson. Retromer dysfunction has been associated with age-related neurodegenerative diseases that are protected by dietary restriction, specifically Alzheimer’s and Parkinson’s diseases.

Overall, their results told the story of how dietary restriction slows brain aging by the action of mtd/OXR1 in maintaining the retromer. “This work shows that the retromer pathway, which is involved in reusing cellular proteins, has a key role in protecting neurons when nutrients are limited,” said Kapahi. The team found that mtd/OXR1 preserves retromer function and is necessary for neuronal function, healthy brain aging, and lifespan extension seen with dietary restriction.

“Diet is influencing this gene. By eating less, you are actually enhancing this mechanism of proteins being sorted properly in your cells, because your cells are enhancing the expression of OXR1,” said Wilson.

The team also found that boosting mtd in flies caused them to live longer, leading researchers to speculate that in humans excess expression of OXR1 might help extend lifespan. “Our next step is to identify specific compounds that increase the levels of OXR1 during aging to delay brain aging,” said Ellerby.

“Hopefully from this we can get more of an idea of why our brains degenerate in the first place,” said Wilson.

“Diet impacts all the processes in your body,” he said. “I think this work supports efforts to follow a healthy diet, because what you eat is going to affect more than you know.”

Source: Buck Institute for Research on Aging

Categories : Diet and NutritionTags :

Slower Long-term Weight Gain Seen for Low-carb, Plant-rich Diets

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Low-carbohydrate diets of mostly plant-based proteins and fats with healthy carbohydrates such as whole grains were associated with slower long-term weight gain than low-carbohydrate diets of mostly of animal proteins and fats with unhealthy carbohydrates like refined starches, according to a new study led by Harvard T.H. Chan School of Public Health. The study was published in JAMA Network Open.

“Our study goes beyond the simple question of, ‘To carb or not to carb?'” said lead author Binkai Liu, research assistant in the Department of Nutrition. “It dissects the low-carbohydrate diet and provides a nuanced look at how the composition of these diets can affect health over years, not just weeks or months.”

While many studies have shown the benefits of cutting carbohydrates for short-term weight loss, little research has been conducted on low-carbohydrate diets’ effect on long-term weight maintenance and the role of food group quality.

Using data from the Nurses’ Health Study, Nurses’ Health Study II, and Health Professionals Follow-up Study, the researchers analysed the diets and weights of 123 332 healthy adults from 1986 to 2018.

Each participant provided self-reports of their diets and weights every four years.

The researchers scored participants’ diets based on how well they adhered to five categories of low-carbohydrate diet: total low-carbohydrate diet (TLCD), emphasising overall lower carbohydrate intake; animal-based low-carbohydrate diet (ALCD), emphasising animal-based proteins and fats; vegetable-based low-carbohydrate diet (VLCD), emphasising plant-based proteins and fats; healthy low-carbohydrate diet (HLCD), emphasising plant-based proteins, healthy fats, and fewer refined carbohydrates; and unhealthy low-carbohydrate diet (ULCD), emphasising animal-based proteins, unhealthy fats, and carbohydrates coming from unhealthy sources such as processed breads and cereals.

The study found that diets comprised of plant-based proteins and fats and healthy carbohydrates were significantly associated with slower long-term weight gain. None of these diets strictly excluded animal or dairy products.

Participants who increased their adherence to TLCD, ALCD, and ULCD on average gained more weight compared to those who increased their adherence to HLCD over time.

These associations were most pronounced among participants who were younger (< 55 years old), overweight or obese, and/or less physically active.

The results for the vegetable-based low carbohydrate diet were more ambiguous: Data from the Nurses’ Health Study II showed an association between higher VLCD scores and less weight gain over time, while data around VLCD scores from the Nurses’ Health Study and Health Professionals Follow-up Study were more mixed.

“The key takeaway here is that not all low-carbohydrate diets are created equal when it comes to managing weight in the long-term,” said senior author Qi Sun, associate professor in the Department of Nutrition.

“Our findings could shake up the way we think about popular low-carbohydrate diets and suggest that public health initiatives should continue to promote dietary patterns that emphasise healthful foods like whole grains, fruits, vegetables, and low-fat dairy products.”

Source: Harvard T.H. Chan School of Public Health

Categories : Diet and Nutrition PaediatricsTags :

For Extremely Prem Babies’ Milk, Which Enrichment is Best?

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Infants born extremely prematurely need enrichment in addition to breast milk, but it wasn’t clear as to whether enrichments were made from breast milk or cow’s milk had an effect on the risk of severe complications. This has been investigated by a large clinical study led by Linköping University, Sweden, published in eClinicalMedicine.

Infants born extremely prematurely, between weeks 22 and 27 of pregnancy, are among the most vulnerable patients in healthcare, at high risk of serious complications and mortality.

There is strong research support for giving breast milk to these children rather than formula made from cow’s milk. Formula based on cow’s milk is known to increase severe the risks for intestinal inflammation and sepsis.

“In Sweden, all extremely preterm infants receive breast milk from their mother or donated breast milk. Despite this, almost one in ten children get a severe inflammation of the intestine called necrotising enterocolitis. It’s one of the worst diseases you can have. At least three out of ten children die and those who survive often have neurological problems afterwards,” says Thomas Abrahamsson, professor at Linköping University and senior physician at the neonatal department at the University Hospital in Linköping, who led the current study.

Historically, there have been very few studies on extremely preterm infants where treatments have been compared against each other.

Therefore, there is a great need for clinical studies that can provide scientific support for how these children should be treated to have better chances of survival and a good life.

In some countries, such as Sweden, infants are fed exclusively with either their mother’s breast milk or donated breast milk.

However, in order for extremely preterm infants to grow as well as possible, they need more nutrition than breast milk contains. This is why breast milk is supplemented with extra protein, so-called enrichment.

The enrichment has previously been made from cow’s milk. But there have been suspicions that cow’s milk-based enrichment increases the risk of severe complications. Today, there is enrichment that is based on donated breast milk, and which has begun to be used in healthcare in some places.

The big question is whether it can reduce the risk of diseases in extremely preterm infants.

The current study, called N-Forte (the Nordic study on human milk fortification in extremely preterm infants), is the largest that has been carried out to seek answers to this question.

The results have been eagerly awaited by paediatricians and others caring for these fragile infants.

“We concluded that it doesn’t matter whether extremely preterm infants get enrichment made from cow’s milk or made from donated breast milk,” says Thomas Abrahamsson.

Although the study indicates that there was no difference between the two options, its results can be useful – the breast milk enrichment is fairly expensive.

“On the one hand, we’re disappointed that we didn’t find a positive effect of enrichment based on breast milk. On the other hand, it’s a large and well-done study and we can now say with great certainty that it doesn’t have an effect in this patient group. This is also important knowledge, so that we don’t invest in expensive products that don’t have the desired effect,” says Thomas Abrahamsson.

The N-Forte study included 228 extremely preterm infants, randomised 1:1 to receive enrichment made from breast milk and cow’s milk respectively.

The researchers examined whether the two groups differed in the incidence of necrotising enterocolitis, sepsis and death.

Of the children treated with breast milk-based enrichment, 35.7% had these complications, while the corresponding proportion was 34.5% in the group receiving cow’s milk-based enrichment, which means that there was no difference between the groups.

The results of the study are in line with a smaller study from Canada published in 2018, where researchers also saw no difference between the two types of enrichment on necrotising enterocolitis and severe sepsis.

Source: Linköping University

Categories : Diet and Nutrition Immune SystemTags :

Yet Another Impact of High-fat Diets: Immune Changes

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A new study from UC Riverside has added more reasons to stick to New Year’s diet resolutions: it showed that that high-fat diets affect genes linked not only to obesity, colon cancer and irritable bowels, but also to the immune system, brain function, and potentially COVID risk.

While other studies have examined the effects of a high-fat diet, this one is unusual in its scope. UCR researchers fed mice three different diets over the course of 24 weeks where at least 40% of the calories came from fat. Then, they looked not only at the microbiome, but also at genetic changes in all four parts of the intestines.

One group of mice ate a diet based on saturated fat from coconut oil, another got a monounsaturated, modified soybean oil, a third got an unmodified soybean oil high in polyunsaturated fat. Compared to a low-fat control diet, all three groups experienced concerning changes in gene expression, the process that turns genetic information into a functional product, such as a protein.

Plant-based or not, high-fat is bad

“Word on the street is that plant-based diets are better for you, and in many cases that’s true. However, a diet high in fat, even from a plant, is one case where it’s just not true,” said Frances Sladek, a UCR cell biology professor and senior author of the new study.

The study, published in Scientific Reports, documents the many impacts of high-fat diets. Some of the intestinal changes did not surprise the researchers, such as major changes in genes related to fat metabolism and the composition of gut bacteria. For example, they observed an increase in pathogenic E. coli and a suppression of Bacteroides, which helps protect the body against pathogens.

Other observations were more surprising, such as changes in genes regulating susceptibility to infectious diseases. “We saw pattern recognition genes, ones that recognise infectious bacteria, take a hit. We saw cytokine signalling genes take a hit, which help the body control inflammation,” Sladek said. ‘So, it’s a double whammy. These diets impair immune system genes in the host, and they also create an environment in which harmful gut bacteria can thrive.”

The team’s previous work with soybean oil documents its link to obesity and diabetes, both major risk factors for COVID. This paper now shows that all three high-fat diets increase the expression of ACE2 and other host proteins that are used by COVID spike proteins to enter the body.

Additionally, the team observed that high-fat food increased signs of stem cells in the colon. “You’d think that would be a good thing, but actually they can be precursors to cancer,” Sladek said.

In terms of effects on gene expression, coconut oil showed the greatest number of changes, followed by the unmodified soybean oil. Differences between the two soybean oils suggest that polyunsaturated fatty acids in unmodified soybean oil, primarily linoleic acid, play a role in altering gene expression.

Negative changes to the microbiome in this study were more pronounced in mice fed the soybean oil diet. This was unsurprising, as the same research team previously documented other negative health effects of high soybean oil consumption.

Soybeans are fine, but watch the oil

In 2015, the team found that soybean oil induces obesity, diabetes, insulin resistance, and fatty liver in mice. In 2020, the researchers team demonstrated the oil could also affect genes in the brain related to conditions like autism, Alzheimer’s disease, anxiety, and depression.

Interestingly, in their current work they also found the expression of several neurotransmitter genes were changed by the high fat diets, reinforcing the notion of a gut-brain axis that can be impacted by diet.

The researchers have noted that these findings only apply to soybean oil, and not to other soy products, tofu, or soybeans themselves. “There are some really good things about soybeans. But too much of that oil is just not good for you,” said UCR microbiologist Poonamjot Deol, who was co-first author of the current study along with UCR postdoctoral researcher Jose Martinez-Lomeli.

Also, the studies were conducted using mice, and mouse studies do not always translate to the same results in humans. However, humans and mice share 97.5% of their working DNA. Therefore, the findings are concerning, as soybean oil is the most commonly consumed oil in the United States, and is increasingly being used in other countries, including Brazil, China, and India.

By some estimates, Americans tend to get nearly 40% of their calories from fat, which mirrors what the mice were fed in this study. “Some fat is necessary in the diet, perhaps 10 to 15%. Most people though, at least in this country, are getting at least three times the amount that they need,” Deol said.

Readers should not panic about a single meal. It is the long-term high-fat habit that caused the observed changes. Recall that the mice were fed these diets for 24 weeks. “In human terms, that is like starting from childhood and continuing until middle age. One night of indulgence is not what these mice ate. It’s more like a lifetime of the food,” Deol said.

That said, the researchers hope the study will cause people to closely examine their eating habits.

Source: University of California – Riverside