In the News
Common food dye can trigger inflammatory bowel diseases
Third of long COVID patients suffer persistent smell loss
New blood test can detect 'toxic' protein years before Alzheimer's symptoms emerge, study shows
Diet change may make biggest impact on reducing heart risk in people with hypertension
Adding yoga to regular exercise improves cardiovascular health and wellbeing
Common food dye can trigger inflammatory bowel diseases
Long-term consumption of Allura Red food dye can be a potential trigger of inflammatory bowel diseases (IBDs), Crohn's disease and ulcerative colitis, says McMaster University's Waliul Khan. Researchers using experimental animal models of IBD found that continual exposure to Allura Red AC harms gut health and promotes inflammation.
The dye directly disrupts gut barrier function and increases the production of serotonin, a hormone/neurotransmitter found in the gut, which subsequently alters gut microbiota composition leading to increased susceptibility to colitis.
Khan said Allura Red (also called FD&C Red 40 and Food Red 17), is a common ingredient in candies, soft drinks, dairy products and some cereals. The dye is used to add colour and texture to foodstuffs, often to attract children.
The use of synthetic food dyes such as Allura Red has increased significantly over the last several decades, but there has been little earlier study of these dyes' effects on gut health. Khan and his team published their findings in Nature Communications. Yun Han (Eric) Kwon, who recently completed PhD in Khan's laboratory, is first author.
"This study demonstrates significant harmful effects of Allura Red on gut health and identifies gut serotonin as a critical factor mediating these effects. These findings have important implication in the prevention and management of gut inflammation," said Khan, the study's senior author, a professor of the Department of Pathology and Molecular Medicine and a principal investigator of Farncombe Family Digestive Health Research Institute.
"What we have found is striking and alarming, as this common synthetic food dye is a possible dietary trigger for IBDs. This research is a significant advance in alerting the public on the potential harms of food dyes that we consume daily," he said.
"The literature suggests that the consumption of Allura Red also affects certain allergies, immune disorders and behavioural problems in children, such as attention deficit hyperactivity disorder."
Khan said that IBDs are serious chronic inflammatory conditions of the human bowel that affect millions of people worldwide. While their exact causes are still not fully understood, studies have shown that dysregulated immune responses, genetic factors, gut microbiota imbalances, and environmental factors can trigger these conditions.
In recent years there has been significant progress in identifying susceptibility genes and understanding the role of the immune system and host microbiota in the pathogenesis of IBDs. However, similar advances in defining environmental risk factors have lagged, he said.
Khan said that environmental triggers for IBDs include the typical Western diet, which includes processed fats, red and processed meats, sugar and a lack of fibre. He added that the Western diet and processed food also includes large amounts of various additives and dyes.
He added that the study suggests a link between a commonly used food dye and IBDs and warrants further exploration between food dyes and IBDs at experimental, epidemiological and clinical levels.
The study was funded by the Canadian Institutes of Health Research.
Story Source: McMaster University
Third of long COVID patients suffer persistent smell loss
Smell loss is one of the most prevalent symptoms of long Covid according to a new study from the University of East Anglia.
New research published today reveals that almost a third of long Covid patients suffer persistent smell loss, with almost a fifth experiencing loss of taste.
The team say that Christmas in particular can be a difficult time for people who have lost their sense of smell and taste -- who will be missing out smells like the Christmas tree and mulled wine, or being able to taste their Christmas dinner, mince pies and chocolates.
The research team investigated the prevalence of long Covid, and particularly ear, nose and throat related symptoms such as smell loss and parosmia -- where people experience strange and often unpleasant smell distortions.
Lead researcher Prof Carl Philpott, from UEA's Norwich Medical School, said: "Long Covid is a complex condition that develops during or after having covid, and it is classified as such when symptoms continue for more than 12 weeks.
"Symptoms include headache, myalgia, fatigue and loss of taste and smell. Parosmia can persist for months after initial infection, alongside brain fog and memory loss.
"We wanted to find out more about the prevalence of long Covid, and particularly ear, nose and throat related symptoms such as smell loss and parosmia."
The team looked at results from the UK Coronavirus Infection Survey and analysed information from over 360,000 people in March 2022.
A total of 10,431 participants identified as suffering from long Covid, and were asked about the presence of 23 individual symptoms and the impact of the condition on their day-to-day activities.
Self-reported long Covid was defined as symptoms persisting for more than four weeks after the first suspected coronavirus infection but not explained by another condition.
Prof Philpott said: "We found that almost three percent of the participants self-identified as having long Covid, and if we scale this up to reflect the UK population, it would equate to around 1.8 million people.
"We found that fatigue was the most common symptom, whilst ENT-related symptoms included a loss of smell and taste, vertigo, shortness of breath, wheezing and a sore throat.
"Almost a third of self-reported long Covid patients were suffering persistent smell loss, and almost a fifth were still experiencing loss of taste.
"This is really significant because we know that loss of smell and taste really impacts people's lives. Our previous research has shown that people who have lost their sense of smell also report high rates of depression, anxiety, isolation and relationship difficulties.
"It can disrupt almost every aspect of life -- from everyday concerns about personal hygiene to a loss of sexual intimacy and the break-down of personal relationships.
"Christmas in particular can be a difficult time. So much of our celebration is based around festive smells and tastes -- from the smell of the tree and mulled wine to tasting Christmas dinner, mince pies and chocolates.
"Long Covid is a growing problem in the UK and we need to focus resources on supporting people with loss of smell and taste after Covid infection," he added.
This research was led by the University of East Anglia in collaboration with the charity Fifth Sense which represents those with smell and taste disorders.
Duncan Boak, CEO and founder of of Fifth Sense, said: "Fifth Sense continues to provide support to large numbers of people experiencing ongoing smell loss and parosmia as part of Long Covid symptoms. People tell us they've received little information or support from their doctors and are sometimes spending money on unprescribed and ineffective treatments they have read about online.
Fifth Sense is growing our engagement with health and social care professionals to help them understand the significant impact that smell dysfunction has on so many aspects of people's lives. We want to see greater recognition across the healthcare profession as well as research into new treatments."
'The growing burden of long COVID in the United Kingdom -- insights from the UK Coronavirus Infection Survey' is published in the journal International Forum of Allergy and Rhinology on December 20, 2022.
Story Source: University of East Anglia.
New blood test can detect 'toxic' protein years before Alzheimer's symptoms emerge, study shows
Today, by and large, patients receive a diagnosis of Alzheimer's only after they exhibit well-known signs of the disease, such as memory loss. By that point, the best treatment options simply slow further progression of symptoms.
But research has shown that the seeds of Alzheimer's are planted years -- even decades -- earlier, long before the cognitive impairments surface that make a diagnosis possible. Those seeds are amyloid beta proteins that misfold and clump together, forming small aggregates called oligomers. Over time, through a process scientists are still trying to understand, those "toxic" oligomers of amyloid beta are thought to develop into Alzheimer's.
A team led by researchers at the University of Washington has developed a laboratory test that can measure levels of amyloid beta oligomers in blood samples. As they report in a paper published the week of Dec. 5 in the Proceedings of the National Academy of Sciences, their test -- known by the acronym SOBA -- could detect oligomers in the blood of patients with Alzheimer's disease, but not in most members of a control group who showed no signs of cognitive impairment at the time the blood samples were taken.
However, SOBA did detect oligomers in the blood of 11 individuals from the control group. Follow-up examination records were available for 10 of these individuals, and all were diagnosed years later with mild cognitive impairment or brain pathology consistent with Alzheimer's disease. Essentially, for these 10 individuals, SOBA had detected the toxic oligomers before symptoms surfaced.
"What clinicians and researchers have wanted is a reliable diagnostic test for Alzheimer's disease -- and not just an assay that confirms a diagnosis of Alzheimer's, but one that can also detect signs of the disease before cognitive impairment happens. That's important for individuals' health and for all the research into how toxic oligomers of amyloid beta go on and cause the damage that they do," said senior author Valerie Daggett, a UW professor of bioengineering and faculty member in the UW Molecular Engineering & Sciences Institute. "What we show here is that SOBA may be the basis of such a test."
SOBA, which stands for soluble oligomer binding assay, exploits a unique property of the toxic oligomers. When misfolded amyloid beta proteins begin to clump into oligomers, they form a structure known as an alpha sheet. Alpha sheets are not ordinarily found in nature, and past research by Daggett's team showed that alpha sheets tend to bind to other alpha sheets. At the heart of SOBA is a synthetic alpha sheet designed by her team that can bind to oligomers in samples of either cerebrospinal fluid or blood. The test then uses standard methods to confirm that the oligomers attached to the test surface are made up of amyloid beta proteins.
The team tested SOBA on blood samples from 310 research subjects who had previously made their blood samples and some of their medical records available for Alzheimer's research. At the time the blood samples had been taken, the subjects were recorded as having no signs of cognitive impairment, mild cognitive impairment, Alzheimer's disease or another form of dementia.
SOBA detected oligomers in the blood of individuals with mild cognitive impairment and moderate to severe Alzheimer's. In 53 cases, the research subject's diagnosis of Alzheimer's was verified after death by autopsy -- and the blood samples of 52 of them, which had been taken years before their deaths, contained toxic oligomers.
SOBA also detected oligomers in those members of the control group who, records show, later developed mild cognitive impairment. Blood samples from other individuals in the control group who remained unimpaired lacked toxic oligomers.
Daggett's team is working with scientists at AltPep, a UW spinout company, to develop SOBA into a diagnostic test for oligomers. In the study, the team also showed that SOBA easily could be modified to detect toxic oligomers of another type of protein associated with Parkinson's disease and Lewy body dementia.
"We are finding that many human diseases are associated with the accumulation of toxic oligomers that form these alpha sheet structures," said Daggett. "Not just Alzheimer's, but also Parkinson's, type 2 diabetes and more. SOBA is picking up that unique alpha sheet structure, so we hope that this method can help in diagnosing and studying many other 'protein misfolding' diseases."
Daggett believes the assay has further potential.
"We believe that SOBA could aid in identifying individuals at risk or incubating the disease, as well as serve as a readout of therapeutic efficacy to aid in development of early treatments for Alzheimer's disease," she said.
Lead author on the study is Dylan Shea, a doctoral student in the UW Department of Bioengineering's Molecular Engineering Program. Co-authors are Elizabeth Colasurdo of the VA Puget Sound Health Care System; Alec Smith, a UW research assistant professor of physiology and biophysics; Courtnie Paschall, a student in the UW Medical Scientist Training Program; Dr. Suman Jayadev, a UW assistant professor of neurology; Dr. Dirk Keene, a UW professor of laboratory medicine and pathology; Douglas Galasko, a professor of neurosciences at the University of California, San Diego; Dr. Andrew Ko, assistant professor of neurological surgery at the UW; and Ge Li and Dr. Elaine Peskind, both of the UW Department of Psychiatry and Behavioral Sciences and the VA Puget Sound Health Care System. The research was funded by the National Institutes of Health, the Washington Research Foundation and the Northwest Mental Illness Research, Education and Clinical Center.
Story Source: University of Washington.
Diet change may make biggest impact on reducing heart risk in people with hypertension
According to the 2017 joint American Heart Association and American College of Cardiology High Blood Pressure Guideline, stage 1 hypertension is defined as having a systolic (top number) level of 130-139 mm Hg or having a diastolic (bottom number) measure of 80-89 mm Hg.
The researchers estimate widespread adoption of lifestyle changes, such as limiting heavy alcohol consumption and exercising regularly, may prevent thousands of deaths and save more than one billion dollars in health care costs over the next 10 years. Their analysis found that adoption of the DASH diet could have the greatest benefit, with an estimated 15,000 heart disease events prevented among men and 11,000 event among women.
The DASH eating plan is specifically designed to help manage blood pressure. The diet emphasizes foods including fruits, vegetables, lean meat sources, nut, seeds and grains and limiting consumption of red meat, sodium, sugars and sugar-sweetened beverages.
The research team estimated that 8.8 million U.S. adults, ages 35-64, have untreated stage 1 hypertension and would be recommended lifestyle changes, such as physical activity, sustained weight loss, moderating alcohol intake and adoption of the DASH diet.
In the absence of other health conditions, such as type 2 diabetes or kidney disease, and a predicted >(10%) 10-year CVD risk, people with stage 1 hypertension are considered at low risk for heart attack or stroke compared to people with stage 2 or higher hypertension. Stage 2 hypertension is defined as systolic measures of 140 mm Hg or higher, or diastolic measures of 90 mm Hg or higher. The recommendations for treatment for people with stage 1 hypertension is based primarily on lifestyle changes rather than medication.
"Nearly nine million young and middle-aged adults with untreated stage 1 hypertension represent a significant, impending burden for health care systems," said Kendra D. Sims, Ph.D., M.P.H., a postdoctoral fellow at the University of California, San Francisco and co-lead researcher of this study. "Our results provide strong evidence that large-scale, healthy behavior modifications may prevent future heart disease, related complications and excess health care costs."
To simulate heart disease and stroke events, mortality and health care costs between 2018 and 2027, the researchers applied evidence from published meta-analyses and trial data about the blood-pressure reducing effects of lifestyle changes: dietary changes, sustained weight loss, physical activity, smoking cessation and alcohol moderation. About half of the modeled population were women and 61% (5.5 million) had regular health care access.
The researchers found that making recommended lifestyle changes to control blood pressure to below 130 mm Hg systolic or 90 mm Hg diastolic may have substantial health and economic benefits. They estimated that lifestyle changes could:
- Prevent 26,000 cardiovascular disease events, such as stroke, heart failure or heart attack;
- Avoid 2,900 deaths; and
- Save $1.6 billion in associated health care costs.
"Unfortunately, the availability and affordability of healthy food sources does not easily allow people to follow the DASH diet. Clinicians should consider whether their patients live in food deserts or places with limited walkability. Health counseling should include addressing these specific challenges to blood pressure control," Sims said.
In May, the Association published a policy statement, Strengthening U.S. Food Policies and Programs to Promote Equity in Nutrition Security, which recommends expanding and improving U.S. nutrition policies and programs to ensure all American can access nutritious food. In 2020, the Association launched the National Hypertensive Control Initiative, a collaborative initiative with the U.S. Department of Health and Human Services that aims to improve blood pressure control among the most vulnerable populations, including racial and ethnic minorities.
"Members of many disadvantaged communities face barriers to healthy food and regular health care access," Sims said. "This means they will not be able to benefit from a counseling from a doctor. Future research should investigate the big picture: social conditions granting people the time and resources to make healthy lifestyle choices. Only with this information can we develop policies for the prevention of heart disease, especially for vulnerable adults."
Co-authors of the study are Pengxiao C. Wei, M.P.H.; Brandon K. Bellows, Pharm.D., M.S.; Joanne Penko, M.S., M.P.H.; Susan Hennessy, Ph.D.; Dhruv S. Kazi, M.D., M.S.; Ross Boylan, Ph.D.; Andrew E. Moran, M.D., M.S.; and Kirsten Bibbins-Domingo, Ph.D., M.D.
Story Source: American Heart Association.
Adding yoga to regular exercise improves cardiovascular health and wellbeing
A three-month pilot study of patients with hypertension appearing in the Canadian Journal of Cardiology, published by Elsevier, demonstrates that adding yoga to a regular exercise training regimen supports cardiovascular health and wellbeing and is more effective than stretching exercises. Incorporation of yoga reduced systolic blood pressure and resting heart rate and improved 10-year cardiovascular risk.
Yoga is part of spiritual and exercise practices for millions of people worldwide. With yoga practice becoming a widely accepted form of exercise, the body of yoga research is growing. It is a multifaceted lifestyle activity that can positively enhance cardiovascular health and wellbeing. Physical exercises such as stretching exercises and the physical components of yoga practices have several similarities, but also important differences.
"The aim of this pilot study was to determine whether the addition of yoga to a regular exercise training regimen reduces cardiovascular risk," explained lead investigator Paul Poirier, MD, PhD, Quebec Heart and Lung Institute -- Laval University, and Faculty of Pharmacy, Laval University, Quebec, Canada. "While there is some evidence that yoga interventions and exercise have equal and/or superior cardiovascular outcomes, there is considerable variability in yoga types, components, frequency, session length, duration, and intensity. We sought to apply a rigorous scientific approach to identify cardiovascular risk factors for which yoga is beneficial for at-risk patients and ways it could be applied in a healthcare setting such as a primary prevention program."
Investigators recruited 60 individuals with previously diagnosed high blood pressure and metabolic syndrome for an exercise training program. Over the 3-month intervention regimen, participants were divided into 2 groups, which performed 15 minutes of either structured yoga or stretching in addition to 30 minutes of aerobic exercise training 5 times weekly. Blood pressure, anthropometry, high-sensitivity C-reactive protein (hs-CRP), glucose and lipids levels as well as the Framingham and Reynolds Risk Scores were measured. At baseline, there was no difference between groups in age, sex, smoking rates, body mass index (BMI), resting systolic and diastolic blood pressure, resting heart rate and pulse pressure.
After 3 months, there was a decrease in resting systolic and diastolic blood pressure, mean arterial blood pressure and heart rate in both groups. However, systolic blood pressure was reduced by 10 mmHg with yoga vs 4 mmHg with stretching. The yoga approach also reduced resting heart rate and 10-year cardiovascular risk assessed using Reynold's Risk score.
While yoga has been shown to benefit hypertensive patients, the exact mechanism underlying this positive effect is not fully understood. This pilot randomized study shows that its benefits cannot be simply attributed to stretching alone.
"This study provides evidence for an additional non-pharmacologic therapy option for cardiovascular risk reduction and blood pressure control in patients with high blood pressure, in the setting of a primary prevention exercise program," noted Dr. Poirier. "As observed in several studies, we recommend that patients try to find exercise and stress relief for the management of hypertension and cardiovascular disease in whatever form they find most appealing. Our study shows that structured yoga practices can be a healthier addition to aerobic exercise than simply muscle stretching."
Story Source: Elsevier.