Tag: dairy products

Categories : Diet and NutritionTags :

Could a Latté a Day Keep Inflammation Away?

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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

Categories : AllergiesTags :

For Eosinophilic Oesophagitis, Cutting out Milk is as Effective as More Restrictive Diet

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Eliminating animal milk alone from the diet of adults with eosinophilic oesophagitis (EoE) is as effective at treating the disease as eliminating animal milk plus five other common foods, according to a clinical trial published in The Lancet Gastroenterology & Hepatology. For people with EoE whose disease remains active after they cut out animal milk, a more restrictive diet may help them achieve remission, according to the researchers.

“Diet-based therapy for eosinophilic esophagitis will be much easier to follow for many people if it involves cutting just one food from the diet rather than six,” said Hugh Auchincloss, M.D., acting director of the National Institute of Allergy and Infectious Diseases (NIAID), part of NIH.

EoE is a chronic disease characterised by an overabundance of white blood cells called eosinophils in the pesophagus. Food allergy inflammation drives the disease by damaging the oesophagus and preventing it from working properly. For people with EoE, swallowing even small amounts of food can be a painful and stressful choking experience.

Excluding certain foods from the diet has been a cornerstone of EoE treatment. During the early 2000s, researchers found that eliminating six common food triggers of oesophageal injury (milk, egg, wheat, soy, fish and nuts) substantially reduced signs and symptoms of EoE. This six-food elimination diet (6FED) became a common approach to managing the disease.

In recent years, scientists have conducted small, non-randomised studies of removing one to four of the most common food antigens from the diet to treat EoE, with some success. However, the relative risks and benefits of eliminating many foods versus a few foods at the start of diet-based therapy remained unclear.

The multi-site, randomised trial involved 129 adults ages 18 to 60 years with a confirmed EoE diagnosis, active EoE symptoms, and a high number of eosinophils in oesophageal tissue. Participants were randomised to either the 1FED, which eliminated only animal milk from the diet, or the 6FED. They followed their assigned diet for six weeks, then underwent an upper endoscopy exam and an oesophageal tissue biopsy. If the number of eosinophils in the tissue indicated that EoE was in remission, the participant exited the study. If EoE was not in remission, people who had been on 1FED could advance to 6FED, and people who had been on 6FED could take topical swallowed steroids, both for six weeks, followed by a repeat exam with tissue biopsy.

The investigators found that 34% of participants on 6FED and 40% of participants on 1FED achieved remission after six weeks of diet therapy, a difference that was not statistically significant. The two diets also had a similar impact across several other measures, including reduction in EoE symptoms and effect on quality of life. Thus, 1FED and 6FED were equally effective at treating EoE, an unexpected finding.

The researchers also discovered that nearly half of people who did not respond to 1FED attained remission after treatment with the more restrictive 6FED, while more than 80% of the non-responders to 6FED achieved remission with oral steroids.

Taken together, the investigators conclude that 1FED is a reasonable first-line diet therapy option in adults with EoE, and that effective therapies are available for people who do not achieve remission after 1FED or 6FED.

Source: NIH/National Institute of Allergy and Infectious Diseases

Categories : Diet and Nutrition General InterestTags :

Evolution of Lactose Tolerance Driven by Starvation and Disease

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The ability to digest lactose is thought to have evolved in concert with milk entering the diet where dairy farming was commonplace, but a new study published in Nature paints a much grimmer picture: starvation and disease appeared to drive its spread through European populations.

Five thousand years ago virtually all humans were (like all other mammals) lactose intolerant, losing the ability to produce lactase to digest milk after weaning and suffering bloating, gas and diarrhoea as adults when they they drank milk.

Professor George Davey Smith, Director of the MRC Integrative Epidemiology Unit at the University of Bristol and a co-author of the study, said: “However, a genetic trait called lactase persistence has evolved multiple times over the last 10 000 years and spread in various milk-drinking populations in Europe, central and southern Asia, the Middle East and Africa. Today, around one third of adults in the world are lactase persistent.”

Using archaeological data, genetic samples and computer modelling, the team demonstrated that lactase persistence genetic trait was not common until around 1000 BCE, nearly 4000 years after it was first detected around 4700–4600 BCE.

“The lactase persistence genetic variant was pushed to high frequency by some sort of turbocharged natural selection. The problem is, such strong natural selection is hard to explain,” added Professor Mark Thomas, study co-author from University College London.

In order to establish how lactose persistence evolved, Professor Richard Evershed, the study’s leader, assembled a database of over 7000 animal fat residues from 13 181 pottery fragments. His findings showed that milk was used extensively in European prehistory, dating from the earliest farming nearly 9000 years ago, but its use waxed and waned in different areas and times.

To understand how this relates to the evolution of lactase persistence, the research team, led by Prof Thomas, tracked the presence of the lactase persistence gene using ancient DNA sequences from more than 1700 prehistoric European and Asian individuals. The first instance seen was after around 5000 years ago, and 2000 years later it was at appreciable frequencies and today is very common. Next, his team developed a new statistical approach to examine how well changes in milk use through time explain the natural selection for lactase persistence. Surprisingly, no association was found, challenging the long-held view the extent of milk use drove lactase persistence evolution.

Professor George Davey Smith’s team had been probing the UK Biobank data, comprising genetic and medical data for more than 300 000 living individuals, found only minimal differences in milk drinking behaviour between genetically lactase persistent and non-persistent people. Critically, the large majority of people who were genetically lactase non-persistent experienced no short or long-term negative health effects when they consume milk.

Professor Davey Smith added: “Our findings show milk use was widespread in Europe for at least 9000 years, and healthy humans, even those who are not lactase persistent, could happily consume milk without getting ill. However, drinking milk in lactase non-persistent individuals does lead to a high concentration of lactose in the intestine, which can draw fluid into the colon, and dehydration can result when this is combined with diarrhoeal disease.”

This can have implications for individuals who are unwell, according to Prof Smith. “If you are healthy and lactase non-persistent, and you drink lots of milk, you may experience some discomfort, but you not going to die of it. However, if you are severely malnourished and have diarrhoea, then you’ve got life-threatening problems. When their crops failed, prehistoric people would have been more likely to consume unfermented high-lactose milk – exactly when they shouldn’t.”

To test these ideas, Prof Thomas’s team applied indicators of past famine and pathogen exposure into their statistical models. Their results clearly supported both explanations – the lactase persistence gene variant was under stronger natural selection when there were indications of more famine and more pathogens.

The authors concluded: “Our study demonstrates how, in later prehistory, as populations and settlement sizes grew, human health would have been increasingly impacted by poor sanitation and increasing diarrheal diseases, especially those of animal origin. Under these conditions consuming milk would have resulted in increasing death rates, with individuals lacking lactase persistence being especially vulnerable. This situation would have been further exacerbated under famine conditions, when disease and malnutrition rates are increased. This would lead to individuals who did not carry a copy of the lactase persistence gene variant being more likely to die before or during their reproductive years, which would push the population prevalence of lactase persistence up.

“It seems the same factors that influence human mortality today drove the evolution of this amazing gene through prehistory.”

Source: University of Bristol

Categories : Diseases, Syndromes and ConditionsTags :

Link Between Consuming Dairy Products and MS Flareups Explained

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The reason why multiple sclerosis (MS) sufferers often complain of more severe disease symptoms after consuming dairy products may be down to the milk protein casein, which can trigger inflammation targeting the myelin sheath, according to a study published in the journal PNAS.

This link was demonstrated in mice, but there was evidence of a similar mechanism in humans. The researchers therefore recommend that certain groups of MS sufferers avoid dairy products.

“We hear again and again from sufferers that they feel worse when they consume milk, cottage cheese or yoghurt,” explained Professor Stefanie Kürten from the Institute of Anatomy at University Hospital Bonn. “We are interested in the cause of this correlation.”

The professor of neuroanatomy is considered a renowned expert on multiple sclerosis. “We injected mice with different proteins from cow’s milk,” she said. “We wanted to find out if there was a constituent that they were responding to with symptoms of disease.”

When they administered the cow’s milk constituent casein together with an effect enhancer to the animals, the mice went on to develop neurological disorders. Electron microscopy showed damage to the insulating myelin sheath, which normally prevents short circuits and significantly accelerates stimulus conduction.

In multiple sclerosis, the body’s immune system destroys the myelin sheath. Consequences range from paresthaesia and vision problems to movement disorders. With patients ending up in a wheelchair. In mice, the myelin sheath was also massively perforated, apparently triggered by casein administration. “We suspected that the reason was a misdirected immune response, similar to that seen in MS patients,” explained Rittika Chunder, a postdoctoral fellow in Prof. Kürten’s research group. “The body’s defenses actually attack the casein, but in the process they also destroy proteins involved in the formation of myelin.”

Such cross-reactivity can occur when two molecules share some similar parts, causing the immune system to mistake them for each other. “We compared casein to different molecules that are important for myelin production,” Dr Chunder said. “In the process, we came across a protein called MAG. It looks markedly similar to casein in some respects – so much so that antibodies to casein were also active against MAG in the lab animals.”

This means that in the casein-treated mice, the body’s own defences were also directed against MAG, destabilising the myelin. But to what extent can the results be transferred to people with MS? To answer this question, the researchers added casein antibodies from mice to human brain tissue. These did indeed accumulate in the cells responsible for myelin production in the brain.

The study found that the antibody-producing B cells in the blood of people with MS respond particularly strongly to casein. It is possible that at some point while consuming milk, the affected individuals developed an allergy to casein. Now, on consuming dairy products, the immune system produces masses of casein antibodies, which due to cross-reactivity with MAG, also damage the myelin sheath.

However, this only affects MS patients who are allergic to cow’s milk casein. “We are currently developing a self-test with which affected individuals can check whether they carry corresponding antibodies,” said Prof Kürten. “At least this subgroup should refrain from consuming milk, yogurt, or cottage cheese.”

It is possible that cow’s milk also increases the risk of developing MS in healthy individuals. Because casein can also trigger allergies in them – which is probably not even that rare. Once such an immune response exists, cross-reactivity with myelin can in theory occur. However, this does not mean that hypersensitivity to casein necessarily leads to the development of multiple sclerosis, Prof Kürten stressed. This would presumably require other risk factors. This connection is concerning worrying, said Prof Kürten, as “Studies indicate that MS rates are elevated in populations where a lot of cow’s milk is consumed.”

Source: University of Bonn

Categories : Cardiovascular DiseaseTags :

High Fat Dairy Intake not Tied to CVD Risk

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In a study of countries with high dairy consumption, higher intakes of dairy fat, as measured by bloodstream levels of fatty acids, had a lower risk of cardiovascular disease (CVD) compared to those with low intakes. Higher intakes of dairy fat were not linked to an increased mortality risk.

In a study published in PLoS Medicine, researchers combined results from 4000 Swedish adults with those from 17 similar studies in other countries, creating the most comprehensive evidence to date on the relationship between this more objective measure of dairy fat consumption, risk of  and death.

Dr Matti Marklund from The George Institute for Global Health, Johns Hopkins Bloomberg School of Public Health, and Uppsala University said that with rising dairy consumption around the world, a better understanding of the health impact was needed.

“Many studies have relied on people being able to remember and record the amounts and types of dairy foods they’ve eaten, which is especially difficult given that dairy is commonly used in a variety of foods.

“Instead, we measured blood levels of certain fatty acids, or fat ‘building blocks’ that are found in dairy foods, which gives a more objective measure of dairy fat intake that doesn’t rely on memory or the quality of food databases,” he added.

“We found those with the highest levels actually had the lowest risk of CVD. These relationships are highly interesting, but we need further studies to better understand the full health impact of dairy fats and dairy foods.”

Sweden has one of the world’s highest consumption of dairy. An international team of researchers assessed dairy fat consumption in 4150 Swedish 60-year-olds by measuring blood levels of a particular fatty acid that is mainly found in dairy foods and therefore can be used to reflect intake of dairy fat.

The participants were then followed up for an average of 16 years, recording heart attacks, strokes and other serious circulatory events, and all cause mortality.

After adjustment for other known CVD risk factors including things like age, income, lifestyle, dietary habits, and other diseases, the CVD risk was lowest for those with high levels of the fatty acid (which reflects a high intake of dairy fats). Those with the highest levels had no increased all-cause mortality risk.

These findings highlight the uncertainty of evidence in this area, which is reflected in dietary guidelines, noted  Dr Marklund.

“While some dietary guidelines continue to suggest consumers choose low-fat dairy products, others have moved away from that advice, instead suggesting dairy can be part of a healthy diet with an  emphasis on selecting certain dairy foods — for example, yoghurt rather than butter — or avoiding sweetened dairy products that are loaded with added sugar,” he said.

Combining these results with 17 other studies with a total of almost 43 000 participants from the US, Denmark, and the UK confirmed these findings in other populations.

“While the findings may be partly influenced by factors other than dairy fat, our study does not suggest any harm of dairy fat per se,” Dr. Marklund said.

Lead author Dr Kathy Trieu from The George Institute for Global Health pointed out that consumption of some dairy products, especially fermented products, have been shown to be linked to cardiovascular benefits.

“Increasing evidence suggests that the health impact of dairy foods may be more dependent on the type — such as cheese, yoghurt, milk, and butter — rather than the fat content, which has raised doubts if avoidance of dairy fats overall is beneficial for cardiovascular health,” she said.

“Our study suggests that cutting down on dairy fat or avoiding dairy altogether might not be the best choice for heart health.”

“It is important to remember that although dairy foods can be rich in saturated fat, they are also rich in many other nutrients and can be a part of a healthy diet. However, other fats like those found in seafood, nuts, and non-tropical vegetable oils can have greater health benefits than dairy fats,” Dr Trieu added.

Source: The George Institute for Global Health