Tag: 31/8/22

Increased Risk of Hip Fractures for Women on Vegetarian Diets

Source: Unsplash

Middle-aged women on vegetarian diets have a significantly higher risk of hip fractures than those on diets that include fish or meat, according to a long-term study publish in BMC Central. This risk remained even after accounting for the differences in available nutrient intake and body mass index.

Hip fractures greatly impact quality of life and and health outcomes, and carry a significant financial burden, with an average of $44 000 estimated to spent in the 12 months following a hip fracture. The growing trends of meat-free diets have prompted concern over their impact on hip fracture rates.

While increased intake of vegetable proteins has been associated with lower hip fracture risk, vegetarian diets have also been characterised by lower dietary intakes of nutrients that boost bone mineral density (BMD) and which are more abundant in animal products. Examples include total protein, calcium, vitamin D, vitamin B12, and ω-3 fatty acids, though the relationship with BMD is complex.

The researchers drew on data from the United Kingdom Women’s Cohort Study (UKWCS), and included 26 318 participants aged 35–69 who were classed into regular meat-eaters (> 5 servings/week), occasional meat-eaters (< 5 servings/week), pescatarians (eating fish but no meat) and vegetarians.

On average, vegetarians and pescetarians had a lower BMI (23.3 for both) than regular meat-eaters (25.2). At recruitment, regular meat-eaters had the highest prevalence of CVD, cancer, or diabetes (10.2%), and vegetarians the lowest (5.8%). A higher proportion of vegetarians reported never drinking alcohol. Regular meat-eaters reported the highest absolute dietary intakes of protein, vitamin D, and vitamin B12, whilst vegetarians reported the lowest. Calcium intakes were similar across the diet groups.

Before adjustments, compared with regular meat-eaters, vegetarians (hazard ratio 1.40) but not occasional meat-eaters (1.03) or pescatarians (1.04) had a greater hip fracture risk. Adjustment for confounders slightly attenuated these associations in the adjusted model, but the higher risk in vegetarians remained and was statistically significant: vegetarians 1.33; occasional meat-eaters 1.00; pescatarians 0.97.

However, even after adjustment for factors such as reported differences in nutrient intake and lower BMI, which is a known risk factor in hip fractures, the relative risk difference remained. This suggests that other, as yet unknown, factors related to the diets may be involved.

A New Guideline for Pollen Food Syndrome

Photo by Daria Shevtsova on Pexels

Pollen Food Syndrome (PFS) – also known as oral allergy syndrome or pollen food allergy syndrome – causes affected individuals to experience an allergic reaction when consuming raw plant foods, and triggers can vary depending on an individual’s pollen sensitisation, which in turn is affected by geographical location. A guideline, published in Clinical & Experimental Allergy, has been developed for the diagnosis and management of PFS.

The guideline was drafted by the British Society of Allergy & Clinical Immunology Standards of Care Committee. The correct diagnosis of PFS ensures the avoidance of a misdiagnosis of a primary peanut or tree nut allergy or confusion with another plant food allergy to non-specific lipid transfer proteins. The characteristic foods involved, and rapid-onset oropharyngeal symptoms, mean PFS can often be diagnosed from the clinical history alone. Management focuses on avoiding known trigger foods, which may appear to be simple, but can be difficult if coupled with a pre-existing food allergy, or for individuals following a vegetarian/vegan diet.

“More studies on the effect of PFS on health-related quality of life are needed to dispel the myth that because it usually manifests with mild symptoms, PFS is easily managed, and does not adversely affect the individual,” the authors wrote. “The number of foods and concern about new food triggers means dietary restrictions are often overly strict, so more research on novel treatments of PFS, including food immunotherapy, needs to be undertaken.”

Source: Wiley

A Simple Low-cost Method to Identify Aortic Valve Stenosis

Source: CC0

In the Journal of Applied Physics, researchers developed a method to identify aortic valve stenosis using complex network analysis that is accurate, simple to use, and low-cost.

Aortic valve stenosis occurs when the aortic valve narrows, constricting blood flow from the heart through the artery and to the entire body. In severe cases, it can lead to heart failure. Identifying the condition can be difficult in remote areas because it requires sophisticated technology, and diagnoses at early stages are challenging to obtain.

“Many rural health centres don’t have the necessary technology for analysing diseases like this,” said author M.S. Swapna, of the University of Nova Gorica and the University of Kerala. “For our technique, we just need a stethoscope and a computer.”

The diagnostic tool works based on the sounds produced by the heart. The organ creates a “lub” noise as it closes the mitral and tricuspid valves, pauses as ventricular relaxation occurs and the blood fills in, then makes a second noise, “dub,” as the aortic and pulmonary valves close.

Swapna and her team used heart sound data, collected over 10 minutes, to form a graph. This was then split into sections, with each part representing with a node on the graph. If the sound in that portion of the data was similar to another section, a line was drawn between the two nodes.

In a healthy heart, the graph showed two distinct clusters of points, with many nodes unconnected. In contrast, a heart with aortic stenosis contained many more correlations and edges.

“In the case of aortic stenosis, there is no separation between the ‘lub’ and ‘dub’ sound signals,” explained Swapna.

The researchers used machine learning to examine the graphs and identify those with and without disease, achieving a classification accuracy of 100%. Their method takes the correlation of each point under consideration, making it more accurate than others that only consider the strength of the signal, and it does so in less than 10 minutes. As such, it could be useful for early-stage diagnoses.

So far, the method has only been tested with data, not in a clinical setting. The authors are developing a mobile application that could be accessed worldwide. Their technique could also be used to diagnose other conditions.

“The proposed method can be extended to any type of heart sound signals, lung sound signals, or cough sound signals,” said Swapna.

Source: American Institute of Physics

Scientists Test A Potential New Therapy for Preeclampsia

Pregnant with ultrasound image
Source: Pixabay

Researchers have proposed a new therapy for preeclampsia that corrects the defects identified in placental cells, and restores placental and foetal weight, which they report in the journal Redox Biology. The treatment, tested in two rodent models, successfully lowers blood pressure in the mother and resolves the characteristic preeclampsia symptoms of proteinuria and cardiovascular abnormalities.

Preeclampsia is a placental dysfunction that affects approximately 2 to 8% of pregnant women worldwide. It can have potentially complications for mother and child, and longer-term consequences for the mother. Preeclampsia symptoms are primarily arterial hypertension, proteinuria, abnormal coagulation in the placenta, cardiovascular abnormalities in the mother and foetal growth restriction. Treatments for preeclampsia are limited and mostly involve aspirin as a preventative measure, reducing the procoagulant state in the placenta and partly relieving pressure on the vascular network.

Preeclampsia is characterised by a defective placenta caused by trophoblast dysfunction. Trophoblasts are placental cells that help organise and manage the vascular network which provides the essential resources for foetal growth. At the molecular level, preeclampsia is characterised by an uncontrolled increase in oxidative stress, with excessive production of various reactive species including reactive oxygen and nitrogen species. There is a genetic component: the first gene to be identified as being implicated in the genetic forms of preeclampsia was the STOX1 transcription factor, which controls the expression of thousands of genes, especially those involved in the production of nitric oxide (NO).

In a transgenic mouse model, high accumulation of STOX1 in the placenta induced a preeclampsia-like syndrome. In preeclampsia, NO, a powerful vasodilator that promotes blood flow to the placenta, is mobilised to produce potentially toxic molecules (nitrosative stress) and its levels become insufficient in the placental vascular network, affecting trophoblast function and the vascular network and destabilising other reactive species. This creates a vicious circle and causes uncontrollable oxidative/nitrosative stress with multiple complications, also affecting maternal blood vessel cells, with potentially fatal consequences.

NO is produced by a family of enzymes known as nitric oxide synthases (NOSs). Finding a way of restoring NO production in the placenta via NOSs could represent an effective new therapy to treat preeclampsia. A years-long collaboration gave rise to a potential solution. The scientists’ research was based on trophoblasts overexpressing STOX1 and on two rodent models of preeclampsia, one mimicking early-onset forms via placental overexpression of STOX1 and the other mimicking late-onset forms by partial occlusion of the lower abdominal aorta.

The research revealed a cascade of events that ultimately led the scientists to propose a new therapy. Treating trophoblasts with BH4 (tetrahydrobiopterin, a cofactor that stabilises the NOS enzyme producing NO) corrected the defects identified in these cells, restoring production of NO rather than potentially toxic molecules. More importantly, administering BH4 to the two preclinical rodent models restored placental and foetal weight. Finally, in the early-onset STOX1 preclinical model with significant arterial hypertension and proteinuria, the BH4 treatment corrected blood pressure, excess protein in urine, and cardiovascular abnormalities in the mother. The results even suggest that the treatment may be effective in addressing the long-term effects of preeclampsia on mothers (vascular abnormalities in the brain, kidneys, heart and liver).

This research is the first step towards the development of a therapy for preeclampsia. Genetic analyses of placentas treated with BH4 showed that it corrects the expression of several genes disrupted by excess STOX1 differently than the deregulation induced by aspirin in the placenta. The scientists therefore propose that a treatment combining BH4 and aspirin could be the ultimate therapeutic solution for many cases of preeclampsia. This hypothesis needs to be validated in clinical trials.

Source: Institut Pasteur

Half of Teens Trust Fake Health News

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A new study has found that teenagers have a hard time discerning between fake and true health messages. Only 48% of the participants trusted accurate health messages (without editorial elements) more than fake ones. Meanwhile, 41% considered fake and true neutral messages equally trustworthy and 11% considered true neutral health messages less trustworthy than fake health messages. The results highlight a need for better training of teenagers to navigate a world where fake health news is so widespread.

Health mis- and disinformation are a serious public health concern, with an increased spread of fake health news on social media platforms in the last few years. Previous research has shown that online health messages are mostly incomplete and inaccurate and have potentially harmful health information. Fake health news can lead to poor health choices, risk-taking behaviour, and loss of trust in health authorities.

“There has been an explosion of misinformation in the area of health during the COVID pandemic,” said principal investigator Dr Radomír Masaryk, of Comenius University.

While most research on message credibility has focused on adults, Dr Masaryk and his colleagues investigated whether teenagers are similarly equipped.

“As adolescents are frequent users of the internet, we usually expect that they already know how to approach and appraise online information, but the opposite seems to be true” Dr Masaryk said.

The researchers found that 41% of teenagers couldn’t tell the difference between true and fake online medical content. Additionally, poor editing of health messages was not perceived as a sign of low trustworthiness. These latest findings were published in Frontiers in Psychology.

Teenagers and the media

As so-called ‘digital natives’, modern teenagers are the world’s most well-connected group, with 71% of the world’s youth using the internet.

Studies have shown that teens increase their risky behaviour in response to positive portrayals of risky behaviour in the media, such as smoking and drinking. On the other hand, online health information that supports information provided by professionals can lead to healthy lifestyle changes, self-care, and treatment compliance.

Teenagers look at the structural features of a website, such as language and appearance, to evaluate online information. For example, authoritative organisations, trusted brands, or websites with business-like language tend to be more trusted.

Previous research on message trustworthiness with adolescents identified five editorial elements that deduced perceived message credibility: superlatives, clickbait, grammar mistakes, authority appeal, and bold typeface. Based on this prior study, the researchers developed a method to evaluate the effects of manipulation with content and format of health online messages on their trustworthiness in an adolescent sample.

They presented 300 secondary school students (aged between 16 and 19 years old) with seven short messages about the health promoting effects of different fruits and vegetables. The messages had different levels: fake message, true neutral message, and true message with editorial elements (superlatives, clickbait, grammar mistakes, authority appeal, and bold typeface). Participants were then asked to rate the message’s trustworthiness.

The participants were able to discern between overtly fake health messages and health messages whether true or slightly changed with editing elements; 48% of participants trusted the true neutral health messages more than the fake ones. However, 41% of participants considered fake and true neutral messages equally trustworthy and 11% considered true neutral health messages less trustworthy than fake health messages.

Clickbait less likely to work

“Putting trust in messages requires identification of fake versus true content,” said Dr Masaryk.

In the case of health messages that seem plausible and reasonable, teenagers could not tell the difference between true neutral health messages and health messages with editorial elements. Teenagers did not seem to decide on the trustworthiness of a message based on editing cues.

“The only version of a health message that was significantly less trusted compared to a true health message was a message with a clickbait headline,” continued Dr Masaryk.

The results highlight a need for better instruction of teenagers to spot editing cues that give away the quality of a piece of information. The authors suggest focusing on health literacy and media literacy training, and skills such as analytical thinking and scientific reasoning.

“Analytical thinking and scientific reasoning are skills that help distinguish false from true health messages,” Dr Masaryk concluded.

Source: Frontiers

One Step Close to a Universal Flu Vaccine

Syringe withdrawing from vaccine vial
Photo by Mufid Majnun

A new universal flu vaccine protects against diverse variants of both influenza A and B viruses in mice, according to a new study published in the journal PLOS Pathogens.

The researchers designed a single, universal influenza vaccine candidate with key cross-protective, less variable parts of the influenza A and B viruses: multi-neuraminidase protein subtypes known to be major antiviral drug targets and the universally conserved M2 ectodomain protein.

The researchers, from the Institute for Biomedical Sciences at Georgia State University, report that mice vaccinated with an immune stimulating virus-like particle displaying multiple neuraminidase subtypes and conserved M2 portions of antigens were protected against influenza A seasonal variants and pandemic potential viruses (H1N1, H5N1, H3N2, H9N2 and H7N9) and influenza B (Yamagata and Victoria lineage) viruses containing substantial antigenic variations.

Viral variants emerge when flu pathogens change their major surface haemagglutinin protein that binds to host receptor molecules. Continuous mutational changes in the flu haemagglutinin proteins result in immune escape and sever disease.

Current influenza vaccines are based on strain-specific immunity to haemagglutinin, a highly variable target of immune protection. The effectiveness of the seasonal vaccine is unpredictable and could be below 20% because of continuous changes in haemagglutinin proteins. Influenza therefore remains a significant risk to human health worldwide.

“We developed a single, universal vaccine entity that induced immunity to conserved M2 ectodomain and multi subtype neuraminidase proteins and was found to be effective in conferring broad cross protection against antigenically diverse influenza A and B viruses in young and aged mice,” said Professor Sang-Moo Kang, senior author of the study. “This study provides impactful insight into developing a universal influenza vaccine inducing broad immunity against both flu A and B variants in young and aged populations.”

This study supports a novel strategy for creating a universal vaccine against influenza A and B viruses. A single construct displaying multiple cross protective proteins has the capacity to induce immunity to M2 and multi-subtype neuraminidase proteins of influenza A and B viruses, as well as offer broad cross protection against sickness and mortality under lethal flu virus challenges in mice, according to the study.

Vaccinating mice with this universal vaccine candidate induced broad neuraminidase inhibition, M2 ectodomain specific antibodies and T cell immune responses. Comparable cross protection was induced in aged mice.

The study warrants further testing of this unique, universal va ccine candidate in ferrets, which have similar respiratory tracts to humans.

Source: Georgia State University