Category: Diet and Nutrition

Could a Latté a Day Keep Inflammation Away?

Photo by Porapak Apichodilok on Pexels

A simple latté may have an anti-inflammatory effect in humans, according to a new study published in the Journal of Agricultural and Food Chemistry. The researchers found that a combination of proteins and antioxidants, such as in coffee with milk, doubles the anti-inflammatory properties in immune cells. The researchers hope to be able to study the health effects on humans.

Antioxidants known as polyphenols are found in humans, plants, fruits and vegetables. This group of antioxidants is also used by the food industry to slow the oxidation and deterioration of food quality and thereby avoid off flavours and rancidity. Polyphenols are also known to be healthy for humans, as they help reduce oxidative stress in the body that gives rise to inflammation, which can results from infection but also other causes such as muscle overuse or arthritis.

Despite this, understanding of polyphenols is lacking, and few studies have investigated what happens when polyphenols react with other molecules, such as proteins mixed into foods.

In a new study, researchers at the Department of Food Science, in collaboration with researchers from the Department of Veterinary and Animal Sciences, at University of Copenhagen investigated how polyphenols behave when combined with amino acids, the building blocks of proteins. The results have been promising.

“In the study, we show that as a polyphenol reacts with an amino acid, its inhibitory effect on inflammation in immune cells is enhanced. As such, it is clearly imaginable that this cocktail could also have a beneficial effect on inflammation in humans. We will now investigate further, initially in animals. After that, we hope to receive research funding which will allow us to study the effect in humans,” says Professor Marianne Nissen Lund from the Department of Food Science, who headed the study.

The study has just been published in the Journal of Agricultural and Food Chemistry. 

Twice as good at fighting inflammation

To investigate the anti-inflammatory effect of combining polyphenols with proteins, the researchers applied artificial inflammation to immune cells. Some of the cells received various doses of polyphenols that had reacted with an amino acid, while others only received polyphenols in the same doses. A control group received nothing.

The researchers observed that immune cells treated with the combination of polyphenols and amino acids were twice as effective at fighting inflammation as the cells to which only polyphenols were added.

“It is interesting to have now observed the anti-inflammatory effect in cell experiments. And obviously, this has only made us more interested in understanding these health effects in greater detail. So, the next step will be to study the effects in animals,” says Associate Professor Andrew Williams of the Department of Veterinary and Animal Sciences at the Faculty of Health and Medical Sciences, who is also senior author of the study.

Found in coffee with milk

Previous studies by the researchers demonstrated that polyphenols bind to proteins in meat products, milk and beer. In another new study, they tested whether the molecules also bind to each other in a coffee drink with milk. Indeed, coffee beans are filled with polyphenols, while milk is rich in proteins.

“Our result demonstrates that the reaction between polyphenols and proteins also happens in some of the coffee drinks with milk that we studied. In fact, the reaction happens so quickly that it has been difficult to avoid in any of the foods that we’ve studied so far,” says Marianne Nissen Lund.

Therefore, the researcher does not find it difficult to imagine that the reaction and potentially beneficial anti-inflammatory effect also occur when other foods consisting of proteins and fruits or vegetables are combined.

“I can imagine that something similar happens in, for example, a meat dish with vegetables or a smoothie, if you make sure to add some protein like milk or yoghurt,” says Marianne Nissen Lund.   

Spurred by polyphenols’ benefits, researchers and industry are working on how to add the right quantities of polyphenols in foods to achieve the best quality. The new research results are promising in this context as well:

“Because humans do not absorb that much polyphenol, many researchers are studying how to encapsulate polyphenols in protein structures which improve their absorption in the body. This strategy has the added advantage of enhancing the anti-inflammatory effects of polyphenols,” explains Marianne Nissen Lund.

Source: University of Copenhagen

‘Eating the Rainbow’ Found to Reduce Prostate Cancer Risk and Improve Treatment

Photo by Brad West on Unsplash

New research by scientists at the University of South Australia suggests that consumption of colourful fruits and vegetables on a regular basis reduces the risk of a prostate cancer (PC) diagnosis. These foods, rich in micronutrients, also help speed up recovery from radiotherapy for the disease.

The findings, from two studies published in the journal Cancershighlight the importance of a Mediterranean or Asian diet that includes these foods. For the first study, researchers compared micronutrient plasma concentrations of prostate cancer patients with a healthy control group, revealing low levels of lutein, lycopene, alpha-carotene, and selenium in PC patients and high levels of iron, sulphur, and calcium in the same group, relative to controls.

The second study found increased DNA damage after radiation exposure was also associated with low lycopene and selenium in blood plasma.

Men with plasma concentrations lower than 0.25ug/mL) for lycopene and/or lower than 120ug/L for selenium have an increased risk of prostate cancer and are likely to be more sensitive to the damaging effects of radiation.

Foods that are rich in lycopene include tomatoes, melons, papayas, grapes, peaches, watermelons, and cranberries. Selenium-rich foods include white meat, fish, shellfish, eggs, and nuts.

Study co-author Dr Permal Deo says that studies show that eating foods rich in lycopene and selenium is preferable to taking supplements, where the benefits are limited.

“Our recommendation is to adopt a Mediterranean diet enlisting the help of a dietician because people absorb nutrients in different ways, depending on the food, the digestive system, the person’s genotype and possibly their microbiome,” Dr Deo says.

Prostate cancer remains one of the most common and fatal cancers in men, but the nutritional deficiencies associated with it remain largely unknown, hence this study. Other risk factors, such as ethnicity, family history and age have previously been linked to prostate cancer.

“There is strong evidence that being overweight and tall increases the risk of prostate cancer. Diets high in dairy products and low in vitamin E may also increase the risk but the evidence is less clear.”

Source: University of South Australia

Vitamin D Supplements may Ward off Dementia

Vitamin D pills
Photo by Michele Blackwell on Unsplash

Taking vitamin D supplements may help ward off dementia, according to a new, large-scale study published in Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring.

Canadian and UK researchers explored the relationship between vitamin D supplementation and dementia in more than 12 388 participants of the US National Alzheimer’s Coordinating Center, who had a mean age of 71 and were dementia-free when they signed up.

The team found that taking vitamin D was associated with living dementia-free for longer, and they also found 40% fewer dementia diagnoses in the group who took supplements.

Of the group, 2696 participants progressed to dementia over ten years; amongst them, 2017 (75%) had no exposure to vitamin D throughout all visits prior to dementia diagnosis, and 679 (25%) had baseline exposure.

Professor Zahinoor Ismail, of the University of Calgary and University of Exeter, who led the research, said: “We know that vitamin D has some effects in the brain that could have implications for reducing dementia, however so far, research has yielded conflicting results. Our findings give key insights into groups who might be specifically targeted for vitamin D supplementation. Overall, we found evidence to suggest that earlier supplementation might be particularly beneficial, before the onset of cognitive decline.”

While Vitamin D was effective in all groups, the team found that effects were significantly greater in females, compared to males. Similarly, effects were greater in people with normal cognition, compared to those who reported signs of mild cognitive impairment – changes to cognition which have been linked to a higher risk of dementia.

The effects of vitamin D were also significantly greater in people who did not carry the APOEe4 gene, known to present a higher risk for Alzheimer’s dementia, compared to non-carriers. The authors suggest that people who carry the APOEe4 gene absorb vitamin D better from their intestine, which might reduce the vitamin D supplementation effect. However, no blood levels were drawn to test this hypothesis.

Previous research has found that low levels of vitamin D are linked to higher dementia risk. Vitamin D is involved in the clearance of amyloid in the brain, the accumulation of which is one of the hallmarks of Alzheimer’s disease. Studies have also found that vitamin D may provide help to protect the brain against build-up of tau, another protein involved in the development of dementia.

Co-author Dr Byron Creese, at the University of Exeter, said: “Preventing dementia or even delaying its onset is vitally important given the growing numbers of people affected. The link with vitamin D in this study suggests that taking vitamin D supplements may be beneficial in preventing or delaying dementia, but we now need clinical trials to confirm whether this is really the case. The ongoing VitaMIND study at the University of Exeter is exploring this issue further by randomly assigning participants to either take vitamin D or placebo and examining changes in memory and thinking tests over time.”

Source: University of Exeter

Edible Mushroom Found to Promote Neuron Regeneration and Memory

By Nina Filippova, CC BY 4.0, Wikimedia Commons

Researchers have found that compounds in the edible Lions’ Mane mushroom (Hericium erinaceus), already used in herbal medicine for stomach complaints, can promote nerve growth and boost memory. Their findings are published in The Journal of Neurochemistry.

The compounds are neurotrophins – a family of proteins associated with the growth, functioning and maintenance of neurons. In mammals, brain-derived neurotrophic factor (BDNF) is highly expressed in central nervous system neurons. Because BDNF pathway impairment is associated with several diseases, including schizophrenia, Alzheimer’s disease, Rett syndrome, and Huntington’s disease, experimental treatments for neurological and neurodegenerative disorders often target neutrophins.

So far, such treatments have run into problems with crossing the blood-brain barrier and off-target effects. H. erinaceus is high in neutrophins, though it has traditionally been used in herbal medicine to treat stomach complaints and cancer. It is also known for promoting peripheral nerve regeneration.

Two of the biologically active types of compounds, hericenones and erinacines, can successfully cross the the blood-brain barrier and confer neuroprotective effects.

The researchers tested crude and purified H. erinaceus extracts and found that they exhibited BDNF-like neurotrophic activity in both in vitro cultured hippocampal neurons and in mouse models of hippocampal memory. The extracts also promoted neurite outgrowth and improved memory.

They concluded that Hericene A acts through a novel signalling pathway, giving rise to improved cognitive performance. These findings however will need to be validated by future research.

Changing the Structure of Fibre to be Even Better for the Gut

Gut microbiome. Credit: Darryl Leja, NIH

Changing the structure of a dietary fibre commonly found in a range of food products has been found to promote healthy gut bacteria and reduce gas formation, a finding that could help people with intolerances to fibre and irritable bowel conditions. The findings have been published in Food Hydrocolloids.

A team of scientists from the University of Nottingham, Quadram Institute Biosciences and the University of East Anglia examined psyllium, a type of natural dietary fibre that is used in a range of products including cereals and yoghurts. They showed that the physical state of the fibre has a major impact on gas production which often is linked to bowel discomfort.

The team performed in vitro fermentation experiments seeded with human stool. They conducted analysis of fermentation products and evaluated the impact of different structures on the broad categories of microorganisms.

Dr Gleb Yakubov, Associate Professor in Food Physics at the University of Nottingham was one of the lead researchers on the study, he explains: “Although fibre is an important part of any diet, for many people it can cause bowel discomfort and for people with IBS or IBD fibre can be a trigger. This is because some foods cause bacterial interactions in the gut that create gas that can lead to pain or discomfort. Our study shows that the physical state of the fibre has a major impact on gas production by creating beneficial compounds that promote the creation of the good bacteria in the gut.”

Psyllium fibre comes from the seeds of Plantago ovata plants, known by many common names such as blond plantain. These seeds produce a jelly-like material called mucilage, which comes in a variety of shapes and forms and these feature long-chain sugars, called polysaccharides. It is these polysaccharides that lead to the production of beneficial short-chain fatty acids that contribute positively to gut health and systemic metabolism. This study shows that different physical states of fibre impact the way dietary fibre breaks down and that microbes ‘colonise fibre’ during fermentation.

Professor Yakubov continues: “These findings show that there are new opportunities for designing targeted structures using psyllium, either through seed processing or selective breeding, to achieve new fibre materials with clear clinical benefit above that of unrefined psyllium powders aiding in the treatment of gastrointestinal discomfort.”

Research is already underway to create and test psyllium-mimicking materials as medical nutrition which could provide a source of fibre for people with some bowel conditions.

Source: University of Nottingham

Some Dipeptides Found in Meat are Potent Antioxidants

Photo by Jose Ignacio Pompe on Unsplash

Imidazole dipeptides (IDPs), which are abundant in meat and fish, have been reported to be effective in relieving fatigue and preventing dementia. Researchers have discovered that most of these IDPs identified in beef, chicken and pork also have remarkably high antioxidant activity. They detailed their findings in the journal Antioxidants.

Professor Hideshi Ihara from the Osaka Metropolitan University Graduate School of Science led a research team that was the first to discover 2-oxo-imidazole-containing dipeptides (2-oxo-IDPs), which have one more oxygen atom than normal IDPs. Found at concentrations of  0.015–0.11% that of normal IDPs, these were also shown to be potent antioxidants.

In their study, the researchers came up with a method for selective and highly sensitive detection of five types of 2-oxo-IDPs using mass spectrometry, which enables quantitative detection of trace 2-oxo-IDPs in living organisms. Using this method, they revealed for the first time that beef, pork, chicken, and other meats contain antioxidants, not only IDPs but a variety of different 2-oxo-IDPs.

“We hope that this research method, which enables advanced analysis of 2-oxo-IDPs, will be applied not only to basic biology but also to medicine, agriculture, and pharmacy, where it will help improve peoples’ health and prevent diseases,” concluded Professor Ihara.

Source: Osaka Metropolitan University

Brown Rice has a Cell-protecting Compound

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Among its many health benefits, brown rice has long been known to protect against oxidative stress – but it was not known which compound was responsible for this. Researchers in Japan have identified the compound that confers this protective effect, with their findings published in the International Journal of Molecular Sciences.

In a recent study led by Professor Yoshimasa Nakamura from the Graduate School of Environmental and Life Science, Okayama University, researchers from Japan have identified cycloartenyl ferulate (CAF) as the main “cytoprotective” or cell-protecting compound in brown rice. CAF is a unique compound owing to its hybrid structure. As Professor Nakamura explains, “CAF is a hybrid compound of polyphenol and phytosterol and is expected to be a potent bioactive substance with various pharmacological properties, such as antioxidant effect and blood fat-lowering effect.”

In this study, the researchers provide evidence of CAF’s antioxidant properties by demonstrating that it can protect cells from stress caused by hydrogen peroxide. Although hydrogen peroxide is a by-product of a cell’s metabolic processes, abnormal amounts of the compound can be toxic to cells and cause irreversible damage. Treatment of cells with CAF increased their resistance to toxic stress induced by hydrogen peroxide. Moreover, CAF provided greater protection from hydrogen peroxide-induced stress compared to alpha-tocopherol and gamma-tocopherol, two other prominent antioxidant compounds that were earlier speculated to be major contributors to the antioxidant capacity of brown rice.

According to the study’s estimates, the amount of CAF in the whole grain of brown rice is five-fold higher than that of other antioxidant compounds found in brown rice. Further, CAF increases the concentration of heme oxygenase-1 or HO-1, an enzyme that facilitates the production of antioxidants. “We demonstrated here that CAF significantly increased the mRNA level of HO-1, the small molecular weight antioxidant-producing enzyme, at concentrations similar to that required for cytoprotective effects in resistance to oxidative damage,” Professor Nakamura explains.

The researchers further explored this mechanism of action through experiments where blocking HO-1 activity using inhibitors reduced the antioxidant effect of CAF considerably. The high abundance and unique mechanism of action are evidence that CAF is the major contributing antioxidant in brown rice.

Through this study, the researchers have not only uncovered the secret to the health benefits of brown rice, but also locked down on the component that is majorly responsible for these benefits. This will allow the use of CAF in the development of better novel supplements and food products focused on consumer health. As an optimistic Professor Nakamura observes, “Our study can help in the development of new functional foods and supplements based on the functionality of CAFs, like CAF-based nutraceuticals.”

Source: Okayama University

Salt Cuts off Regulatory T Cells’ Energy Supply

Spilled salt shaker
Source: Pixabay CC0

Regulatory T cells ensure that immune responses happen in a controlled way. But eating too much salt weakens these cells’ energy supply, thus rendering them temporarily dysfunctional. This salt-induced ‘load shedding’ may have implications for autoimmunity, researchers report in Cell Metabolism.

Excessive salt consumption not only causes cardiovascular problems, it could also adversely impact the immune system. The study found that salt can disrupt regulatory T cells by impairing their energy metabolism. The findings may provide new avenues for exploring the development of autoimmune and cardiovascular diseases.

A few years ago, research by teams led by Professor Dominik Müller and Professor Markus Kleinewietfeld revealed that excess salt in the diet can negatively affect the metabolism and energy balance in certain types of innate immune cells called monocytes and macrophages and stop them from working properly. They further showed that salt triggers malfunctions in the mitochondria. Inspired by these findings, the research groups wondered whether excessive salt intake might also create a similar problem in adaptive immune cells like regulatory T cells.

Important immune regulators

Regulatory T cells, also known as Tregs, are an essential part of the adaptive immune system. They are responsible for maintaining the balance between normal function and unwanted excessive inflammation.

Scientists believe that the deregulation of Tregs is linked to the development of autoimmune diseases like multiple sclerosis. Recent research has identified problems in mitochondrial function of Tregs from patients with autoimmunity, yet the contributing factors remain elusive.

“Considering our previous findings of salt affecting mitochondrial function of monocytes and macrophages as well as the new observations on mitochondria in Tregs from autoimmune patients, we were wondering if sodium might elicit similar issues in Tregs of healthy volunteers,” says Müller, who co-heads the Hypertension-Mediated End-Organ Damage Lab at the Max Delbrück Center and the ECRC.

Previous research has also shown that excess salt could impact Treg function by inducing an autoimmune-like phenotype. In other words, too much salt makes the Treg cells look like those involved in autoimmune conditions. However, exactly how sodium impairs Treg function had not yet been uncovered.

Salt interferes with mitochondrial function of Tregs

The new international study led by Kleinewietfeld and Müller has now discovered that sodium disrupts Treg function by altering cellular metabolism through interference with mitochondrial energy generation. This mitochondrial problem seems to be the initial step in how salt modifies Treg function, leading to changes in gene expression that showed similarities to those of dysfunctional Tregs in autoimmune conditions.

Even a short-term disruption of mitochondrial function had long-lasting consequences for the fitness and immune-regulating capacity of Tregs in various experimental models. The new findings suggest that sodium may be a factor that could contribute to Treg dysfunction, potentially playing a role in different diseases, although this needs to be confirmed in further studies.

“The better understanding of factors and underlying molecular mechanisms contributing to Treg dysfunction in autoimmunity is an important question in the field. Since Tregs also play a role in diseases such as cancer or cardiovascular disease, the further exploration of such sodium-elicited effects may offer novel strategies for altering Treg function in different types of diseases,” says Kleinewietfeld, who heads the VIB Laboratory for Translational Immunomodulation. “However, future studies are needed to understand the molecular mechanisms in more detail and to clarify their potential relationship to disease.”

Source: Max Delbrück Center for Molecular Medicine in the Helmholtz Association

Fructose Could Drive Alzheimer’s Disease

An ancient human instinct for foraging, fuelled by fructose production in the brain, may hold clues to the development and possible treatment of Alzheimer’s disease (AD), according to a new study published recently in The American Journal of Clinical Nutrition.

The findings provide a new way of looking at the neurodegenerative disease.

“We make the case that Alzheimer’s disease is driven by diet,” said the study’s lead author Richard Johnson, MD, professor at the University of Colorado School of Medicine specializing in renal disease and hypertension. The study co-authors include Maria Nagel, MD, research professor of neurology at the CU School of Medicine.

Johnson and his team suggest that AD is a harmful adaptation of an evolutionary survival pathway used in animals and our distant ancestors during times of scarcity.

“A basic tenet of life is to assure enough food, water and oxygen for survival,” the study said. “Much attention has focused on the acute survival responses to hypoxia and starvation. However, nature has developed a clever way to protect animals before the crisis actually occurs.”

When threatened with the possibility of starvation, early humans developed a survival response which sent them foraging for food. Yet foraging is only effective if metabolism is inhibited in various parts of the brain. Foraging requires focus, rapid assessment, impulsivity, exploratory behavior and risk taking. It is enhanced by blocking whatever gets in the way, like recent memories and attention to time. Fructose, a kind of sugar, helps damp down these centers, allowing more focus on food gathering.

In fact, the researchers found the entire foraging response was set in motion by the metabolism of fructose whether it was eaten or produced in the body. Metabolizing fructose and its byproduct, intracellular uric acid, was critical to the survival of both humans and animals.

The researchers noted that fructose reduces blood flow to the brain’s cerebral cortex involved in self-control, as well as the hippocampus and thalamus. Meanwhile, blood flow increased around the visual cortex associated with food reward. All of this stimulated the foraging response.

“We believe that initially the fructose-dependent reduction in cerebral metabolism in these regions was reversible and meant to be beneficial,” Johnson said. “But chronic and persistent reduction in cerebral metabolism driven by recurrent fructose metabolism leads to progressive brain atrophy and neuron loss with all of the features of AD.”

Johnson suspects the survival response, what he calls the `survival switch,’ that helped ancient humans get through periods of scarcity, is now stuck in the `on’ position in a time of relative abundance. This leads to the overeating of high fat, sugary and salty food prompting excess fructose production.

Fructose produced in the brain can lead to inflammation and ultimately Alzheimer’s disease, the researchers theorised. Animals given fructose show memory lapses, a loss in the ability to navigate a maze and inflammation of the neurons.

“A study found that if you keep laboratory rats on fructose long enough they get tau and amyloid beta proteins in the brain, the same proteins seen in Alzheimer’s disease,” Johnson said. “You can find high fructose levels in the brains of people with Alzheimer’s as well.”

Johnson suspects that the tendency of some AD patients to wander off might be a vestige of the ancient foraging response.

The study said more research is needed on the role of fructose and uric acid metabolism in AD.

“We suggest that both dietary and pharmacologic trials to reduce fructose exposure or block fructose metabolism should be performed to determine if there is potential benefit in the prevention, management or treatment of this disease,” Johnson said.

Source: University of Colorado Anschutz Medical Campus

A High-fat Diet Might be Useful in Expelling Intestinal Worms

Photo by Jonathan Borba on Unsplash

Scientists have discovered that a high-fat diet might actually have a benefit in some cases: it allows the immune system to eliminate a parasitic worm which is a major cause of death and illness in the developing world. Their findings appear in the journal Mucosal Immunology.

Parasitic worms affect up to a billion people, particularly in developing nations with poor sanitation. One of these parasites known as “whipworm” can cause long lasting infections in the large intestine.

Lead author Dr Evelyn Funjika, formerly at Manchester and now at the University of Zambia, said: “Just like the UK, the cheapest diets are often high in fat and at-risk communities to whipworm are increasingly utilising these cheap diets. Therefore, how worm infection and western diets interact is a key unknown for developing nations.

“In order to be able to study how nutrition affects parasite worm infection, we have been using a mouse model, Trichuris muris, closely related to the human whipworm Trichuris trichiura and seeing how a high-fat diet impacts immunity.”

It has been previously shown that immune responses which expel the parasite rely on white blood cells called T-helper 2 cells, specialised for eliminating gastrointestinal parasites.

The findings demonstrate how a high-fat diet, rather than obesity itself, increases a molecule on T-helper cells called ST2 and this allows an increased T-helper 2 response which expels the parasite from the large intestinal lining.

Dr John Worthington from the Department of Biomedical and Life Science at Lancaster University co-led the research.

“We were quite surprised by what we found during this study. High-fat diets are mostly associated with increased pathology during disease. However, in the case of whipworm infection this high fat diet licenses the T-helper cells to make the correct immune response to expel the worm.”

Co-lead Professor Richard Grencis from the University of Manchester said: “Our studies in mice on a standard diet demonstrate that ST2 is not normally triggered when expelling the parasite, but the high-fat diet boosts the levels of ST2 and hence allows expulsion via an alternative pathway.”

Co-lead Professor David Thornton from the University of Manchester added: “It was really fascinating that simply altering the diet completely switched the immune response in the gut from one that fails to expel the parasite, to one that brings about all the correct mechanisms to eliminate it.”

However, Dr Worthington added caution to the findings.

“Before you order that extra take-away, we have previously published that weight loss can aid the expulsion of a different gut parasite worm. So these results may be context specific, but what is really exciting is the demonstration of how diet can profoundly alter the capacity to generate protective immunity and this may give us new clues for treatments for the millions who suffer from intestinal parasitic infections worldwide.”

Source: Lancaster University