sábado, 31 de agosto de 2019

Thermography versus Mammography: Which is Best?

Thermography versus Mammography: Which is Best?

News-Medical

Thermography versus Mammography: Which is Best?

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Breast cancer is among the leading causes of death among women between 25 and 65 years, with an expected incidence of 1 in 8 women in most countries. Screening and early diagnosis are still the best way to reduce the number of breast cancer deaths.  However, there is some debate over the best method of screening patients for this disease.
Mammography is currently the most widely accepted screening technique. The US Food and Drug Administration, along with many other national societies, still describes it as the most effective screening test for breast cancer. Yet some doctors have advocated using Thermography despite a lack of evidence that it can reliably detect breast cancer as sensitively as mammography.

What is Mammography?

Mammography is a radiographic method which uses low-dose X-rays to image the breast tissue for both screening and diagnosis of breast cancer. Any suspicious high density regions or unusual patterns such as microcalcifications are examined carefully. These could be due to a range of abnormalities, such as tumors (benign and malignant), fibroadenomas, or cysts with solid areas.
A good mammogram requires firm breast compression against the detector. This minimizes breast movement and allows for the clearest image, it also provides the shortest distance between the breast and detector at all points, reducing the number of films and radiation exposure, while allowing single-plane imaging of the whole breast.

Obesity Prevalence Among Cannabis Users

Obesity Prevalence Among Cannabis Users

News-Medical



Obesity Prevalence Among Cannabis Users

Teenagers exposed to air pollution show greater autonomic reactivity to social stress

Teenagers exposed to air pollution show greater autonomic reactivity to social stress

News-Medical

Teenagers exposed to air pollution show greater autonomic reactivity to social stress

Adolescents exposed to higher levels of fine-particle air pollutants have heightened autonomic nervous system reactions to social stress, reports a study in Psychosomatic Medicine: Journal of Biobehavioral Medicine, the official journal of the American Psychosomatic Society. The journal is published in the Lippincott Portfolio by Wolters Kluwer.
Teens with anxiety and depression appear to be particularly vulnerable to the effects of air pollution on physiological reactions to stress, according to the new research by Jonas G. Miller, PhD, of Stanford University and colleagues. They write,
These findings contribute to a growing literature suggesting that physical pollutants play a significant role in psychosocial functioning."

Psychological factors may affect physiological reactions to pollutants

The experimental study included 144 California adolescents of diverse race/ethnicity and socioeconomic backgrounds. They performed a test designed to elicit heightened levels of stress: being evaluated while giving a five-minute speech and performing a math test. Bodily responses to social stress were measured, including heart rate variability and skin conductance level.
Air pollution monitoring data were used to assess levels of fine-particle air pollutants (PM2.5) in the neighborhoods where the teens lived. Exposure to PM2.5has been linked to increased autonomic imbalance, negative emotional states, and possible short- and long-term health risks.
The investigators found that the social stress test produced increased reactivity of the autonomic nervous system – characteristic of the so-called "fight or flight" response to stress. The increase in autonomic reactivity was greater for teens living in neighborhoods with high levels of PM2.5. Socioeconomic factors did not explain the association between air pollution and autonomic responses to stress.
However, the degree to which PM2.5 and stress reactivity wererelated depended on the adolescents' mental health symptoms. Teens who reported higher levels of anxiety and depression symptoms showed the strongest association between PM2.5and autonomic reactivity to social stress. "In fact, there was not a significant association between PM2.5 and autonomic reactivity in adolescents who reported the least severe anxiety and depression symptoms," Dr. Miller and colleagues note.
The study adds to a growing body of research suggesting that psychological factors influence vulnerability to the negative health effects of environmental pollution. The association might be especially relevant in adolescence, which is already a time of high sensitivity to social stress and evaluation. Pollution-related increases in stress reactivity might play a role in the development of mental and physical health problems.
The links between PM2.5, autonomic reactivity to stress, and mental health symptoms may have important policy and clinical implications, Dr. Miller and colleagues believe. They write, "Limiting exposure to PM2.5might help reduce adolescent reactivity to social stress and evaluation, which appears to be particularly helpful for youth who are experiencing symptoms of anxiety and depression."
Source:
Journal reference:
Miller, J.G. et al. (2019) Fine Particle Air Pollution and Physiological Reactivity to Social Stress in Adolescence. Psychosomatic Medicinedoi.org/10.1097/PSY.0000000000000714.

FSU researcher examines how berry polyphenols could help fight plaque buildup in arteries

FSU researcher examines how berry polyphenols could help fight plaque buildup in arteries

News-Medical

FSU researcher examines how berry polyphenols could help fight plaque buildup in arteries

A Florida State University researcher is examining how the polyphenol compounds found in blackberries could be used to help fight the buildup of artery plaque.
Gloria Salazar, associate professor of nutrition, has received $805,409 from the James and Esther King Biomedical Research Program at the Florida Department of Health to look at the protective effects of polyphenols, bioactive compounds known for their strong antioxidant and anti-inflammatory effects that are found in many fruits and vegetables.
We know that the Mediterranean diet, rich in fruits and vegetables, can be really beneficial to the cardiovascular system. But we don't know if we can use this diet in some way to reduce the effects of specific cardiovascular problems."
Gloria Salazar, associate professor of nutrition, Florida State University
Studies have shown that people who eat diets rich in fruits and vegetable are less likely to have cardiovascular disease, which is largely attributed to the polyphenol content of these foods. However, it is unknown whether this diet could reduce vascular aging, a cellular process -; often brought on by smoking -; that in the long term leads to atherosclerosis. Atherosclerosis is the buildup of plaque in the walls of arteries obstructing the flow of blood.
Salazar has already conducted preliminary studies in mice showing that a diet supplemented with blackberries reduces atherosclerosis. These preliminary results have shown the potential impact of this work, but researchers still have many more questions about how polyphenols could be used to promote cardiovascular health.
Cardiovascular disease is the leading cause of death in the United States and worldwide. A 2015 American Heart Association report found that lifestyle behaviors, like smoking, lack of exercise and poor diet are major contributing factors of death and disability due to cardiovascular disease.
"We are excited about the idea that perhaps concentrated extracts of these berries will work as a therapeutic intervention for people with smoke-related diseases," Salazar said. "Our idea is to use nutrition as a long-term preventative measure against chronic diseases. Can we harness diet and medicine together for better outcomes?"

Eating nuts associated with lower risk of death from cardiovascular disease

Eating nuts associated with lower risk of death from cardiovascular disease

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Eating nuts associated with lower risk of death from cardiovascular disease

Eating nuts at least twice a week is associated with a 17% lower risk of death from cardiovascular disease, according to research presented today at ESC Congress 2019 together with the World Congress of Cardiology.
Nuts are a good source of unsaturated fat and contain little saturated fat. They also have protein, minerals, vitamins, fiber, phytosterols, and polyphenols which benefit heart health. European and US studies have related nuts with cardiovascular protection but there is limited evidence from the Eastern Mediterranean Region."
Study author Dr Noushin Mohammadifard of Isfahan Cardiovascular Research Institute, Iran
This study examined the association between nut consumption and the risk of cardiovascular disease and death in the Iranian population. A total of 5,432 adults aged 35 and older with no history of cardiovascular disease were randomly selected from urban and rural areas of the Isfahan, Arak and Najafabad counties. Intake of nuts including walnuts, almonds, pistachios, hazelnuts, and seeds was assessed in 2001 with a validated food frequency questionnaire.
Participants or family members were interviewed every two years until 2013 for the occurrence of cardiovascular events and death. The specific outcomes investigated were coronary heart disease, stroke, total cardiovascular disease, death from any cause, and death from cardiovascular disease.
During a median 12-year follow-up, there were 751 cardiovascular events (594 coronary heart disease and 157 stroke), 179 cardiovascular deaths, and 458 all-cause deaths.
Eating nuts two or more times per week was associated with a 17% lower risk of cardiovascular mortality compared to consuming nuts once every two weeks. The connection was robust even after adjusting for factors that could influence the relationship such as age, sex, education, smoking, and physical activity. Nut intake was inversely associated with the other outcomes but lost significance after adjustment.
ESC guidelines list 30 grams of unsalted nuts per day as one of the characteristics of a healthy diet, while noting that the energy density of nuts is high.2
"Raw fresh nuts are the healthiest," added Dr Mohammadifard. "Nuts should be fresh because unsaturated fats can become oxidised in stale nuts, making them harmful. You can tell if nuts are rancid by their paint-like smell and bitter or sour taste."

New ESC guidelines for diagnosis and management of pulmonary embolism published

New ESC guidelines for diagnosis and management of pulmonary embolism published

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New ESC guidelines for diagnosis and management of pulmonary embolism published

The European Society of Cardiology (ESC) Guidelines on acute pulmonary embolism are published online today in European Heart Journal, and on the ESC website. They were developed in collaboration with the European Respiratory Society (ERS).
Acute pulmonary embolism is the third most common cause of cardiovascular death in Europe, after heart attack and stroke, contributing to more than 350,000 deaths each year. A blood clot (thrombus) in a deep vein, usually in the legs, is dislodged and travels to the lungs where it blocks one or more vessels. This typically occurs if the vein wall is damaged, blood flow is too slow, or the blood becomes too thick.
Major surgery such as knee or hip replacement, serious injury, prolonged bed rest and cancer are common risk factors for acute pulmonary embolism. It can also happen after long travel and in women who are pregnant or taking the oral contraceptive pill.
Symptoms including shortness of breath and chest pain resemble other diseases so the diagnosis is often missed, or the severity of the situation is underestimated, and many patients die before getting appropriate therapy."
Professor Stavros Konstantinides, Chairperson of the guidelines Task Force and medical director, Centre for Thrombosis and Haemostasis, Johannes Gutenberg University Mainz, Germany
The guidelines clarify how to diagnose acute pulmonary embolism step by step. The process begins with clinical suspicion based on symptoms combined with blood tests (D-dimers). Depending on the severity and urgency of the scenario, a computed tomography (CT) scan may be used to visualize  the lung vessels, or cardiac ultrasound to look at the heart chambers.
A new table shows how CT scans and lung scans compare in their ability to diagnose or exclude pulmonary embolism, and how much radiation the patient receives with each of these tests.
"The aim is to get to the diagnosis as reliably and quickly as possible, in order to start lifesaving therapy and prevent other clots from reaching the lungs," said Professor Guy Meyer, Co‐Chairperson of the guidelines Task Force and respiratory medicine physician, Hôpital Européen Georges-Pompidou, Paris, France.
Anticoagulant drugs (blood thinners) help the body dissolve clots and reopen the blocked vessels. If the patient is in shock and about to collapse, the clot must be removed immediately, and this can be achieved using thrombolytic drugs (clot busters), catheters, or surgery.
The guidelines recommend how to judge the severity of pulmonary embolism based on a combination of clinical, imaging and laboratory results. This will dictate whether blood thinners alone are sufficient or if clot busters, a catheter intervention, or surgical removal is necessary. There is new advice on how to distinguish, in the CT scan, fresh thrombi in the lungs from chronic obstructions due to a disease called chronic thromboembolic pulmonary hypertension (CTEPH), which requires a different type of therapy.
Also new is the guidance on which drugs to use in a patient with pulmonary embolism and cancer. Patients with cancer have a high risk of recurrence, and indefinite anticoagulation is often necessary.
Acute pulmonary embolism is a leading cause of maternal death in high-income countries, but diagnosis can be challenging because symptoms often overlap with those of normal pregnancy. Novel recommendations outline how to diagnose and treat pulmonary embolism in the pregnant patient.
Updated instructions state when it is safe to send patients home from the hospital. Some have a lifelong increased risk of another event. Anticoagulants are used to treat the acute episode and prevent recurrence but raise the risk of bleeding. The guidelines describe how to decide the duration of treatment. They also specify when and how (with which tools and tests) to follow patients, and which findings suggest chronic disease (CTEPH) requiring diagnosis and treatment in an expert center.
Last but not least, the 2019 ESC Guidelines endorse a multidisciplinary approach to pulmonary embolism after the acute phase and discharge of the patient. Teams should include physicians, appropriately qualified nurses, and other allied health professionals, aiming to ensure smooth transitions between hospital specialists and practitioners, optimized long term care and prevention of recurrence.
Advice for patients
  • Be aware of conditions that predispose to acute pulmonary embolism.
  • If you are at increased risk or have previously had pulmonary embolism or deep vein thrombosis, and are admitted to hospital for another disease, ask what is being done to prevent thrombosis.
  • If you have one or more risk factors for pulmonary embolism and feel shortness of breath, chest discomfort or chest pain, lightheaded or faint, call a doctor or ambulance immediately. Lie down and do not move around. Do not walk or drive to the hospital or physician's practice.
  • If you had an acute pulmonary embolism and are on blood thinners, when you are discharged from hospital ask when you need to see a doctor again. At the follow-up visit, report any bleeding and whether you have returned to normal or still have symptoms such as shortness of breath.

ESC guidelines highlight detrimental impact of pollution, noise on patients with chronic coronary syndromes

ESC guidelines highlight detrimental impact of pollution, noise on patients with chronic coronary syndromes

News-Medical

ESC guidelines highlight detrimental impact of pollution, noise on patients with chronic coronary syndromes

The detrimental impact of pollution and noise on patients with chronic coronary syndromes is highlighted for the first time in European Society of Cardiology (ESC) Guidelines published online today in European Heart Journal, and on the ESC website.
Professor Juhani Knuuti, Chairperson of the guidelines Task Force and director of the Turku PET Centre, Finland said:
Air pollution and environmental noise increase the risk of heart attack and stroke, so policies and regulations are needed to minimize both. Patients with chronic coronary syndromes should avoid areas with heavy traffic congestion and may consider wearing a respirator face mask. Air purifiers with high efficiency particulate air filters can be used to reduce indoor pollution."
The document covers chronic coronary syndromes and is a continuation of the previous stable coronary artery disease (CAD) guidelines.
This reflects the fact that CAD can be acute (covered in separate guidelines) or chronic and both are dynamic conditions. Therapy is lifelong and aimed at preventing progression of the disease and cardiac events such as heart attacks."
Professor William Wijns, Chairperson of the guidelines Task Force and professor in interventional cardiology at the Lambe Institute for Translational Medicine, Galway, Ireland
Lifestyle is given stronger emphasis than in the previous document, since unhealthy behaviors will have contributed to the development of a chronic coronary syndrome and changes can prevent it worsening.
Patients should stop smoking, avoid passive smoking, eat a diet high in vegetables, fruit, and whole grains, and limit saturated fat and alcohol. A healthy body weight is advised, plus 30 to 60 minutes of moderate physical activity most days. Sexual activity is low risk for patients with no symptoms (e.g. chest pain). An annual flu vaccination is promoted, particularly for elderly patients, to prevent heart attacks and premature death.
Patients with CAD have a twofold higher risk of mood and anxiety disorders compared to those without. Stress, depression, and anxiety are linked to worse outcomes and make it difficult to improve lifestyle and adhere to medications. Counseling is encouraged for those with depression, anxiety, or stress.
Cognitive behavioral therapy can also help patients achieve a healthy lifestyle - for example supporting patients to set realistic goals, self-monitor, harness support from friends and family, and plan how to implement changes and deal with difficult situations. In addition, some patients - for example after an acute event or the morbidly obese - should be referred to exercise-based cardiac rehabilitation and receive assistance from a multidisciplinary team including cardiologists, GPs, dietitians, physiotherapists, psychologists, and pharmacists.
Patients with chronic coronary syndromes require medication to alleviate symptoms and prevent acute events such as heart attack and cardiac death. Statins are recommended in all patients and antithrombotic drugs in high-risk patients, while other drugs such as angiotensin-converting enzyme (ACE) inhibitors are for specific groups.
"Patients need to take medications as prescribed even if they have no symptoms," said Prof Knuuti. "Promoting behavior change and medication adherence should be part of each appointment with GPs or specialists including nurses and cardiologists."
Revascularization to open blocked arteries is an important therapy for some patients, such as those at high risk of poor outcomes and those whose symptoms are not controlled through lifestyle and drugs.
Diagnosis of chronic coronary syndromes has evolved significantly since the last document. The six most frequently encountered clinical scenarios are outlined:
  • Those with suspected CAD and stable chest pain (angina) or shortness of breath.
  • Patients without symptoms or with stable symptoms less than one year after an acute coronary syndrome or with recent revascularisation.
  • Patients with and without symptoms more than one year after initial diagnosis or revascularisation.
  • Patients with new onset of heart failure or left ventricular dysfunction and suspected CAD.
  • Those with chest pain (angina) and suspected vasospastic or microvascular disease.
  • Asymptomatic patients in whom CAD is detected at screening.
Prof Wijns said:
Each of these scenarios requires different diagnostic and therapeutic approaches. But in general, treatment of a chronic coronary syndrome demands long-lasting healthy habits, medication adherence, and interventions in selected patients."

LDL cholesterol levels should be lowered as much as possible to prevent cardiovascular risk

LDL cholesterol levels should be lowered as much as possible to prevent cardiovascular risk

News-Medical

LDL cholesterol levels should be lowered as much as possible to prevent cardiovascular risk

Low-density lipoprotein (LDL) cholesterol levels should be lowered as much as possible to prevent cardiovascular disease, especially in high and very high risk patients. That's one of the main messages of the European Society of Cardiology (ESC) and European Atherosclerosis Society (EAS) Guidelines on dyslipidaemias published online today in European Heart Journal, and on the ESC website.
Cardiovascular disease (CVD) is responsible for more than four million deaths in Europe each year. Clogged arteries, known as atherosclerotic CVD, are the main type of disease. The guidelines provide recommendations on how to modify plasma lipid levels through lifestyle and medication to reduce the risk of atherosclerotic CVD.
There is now overwhelming evidence from experimental, epidemiological, genetic studies, and randomized clinical trials, that higher LDL cholesterol is a potent cause of heart attack and stroke. Lowering LDL cholesterol reduces risk irrespective of the baseline concentration. It means that in people at very high risk of heart attack or stroke, reducing LDL cholesterol is effective even if they have below average starting levels."
Professor Colin Baigent, Chairperson of the guidelines Task Force and director of the MRC Population Health Research Unit, University of Oxford, UK
There is no lower limit of LDL cholesterol that is known to be unsafe. The guidelines aim to ensure that the available drugs (statins, ezetimibe, PCSK9 inhibitors) are used as effectively as possible to lower levels in those most at risk. It is recommended that such patients should achieve both a target LDL cholesterol level and a minimum 50% relative reduction.
"This is to ensure that high- or very high-risk patients receive intensive LDL cholesterol-lowering therapy irrespective of their baseline level," said Professor Alberico L. Catapano, Chairperson of the guidelines Task Force and professor of pharmacology at the Department of Pharmacological and Biomolecular Sciences, University of Milan, Italy. "Patients who are already close to their target on current treatment will be offered additional treatment that provides a further minimum 50% reduction."
"Statins are very well tolerated, and true 'statin intolerance' is uncommon. Most patients can take a statin regimen," noted Professor François Mach, Chairperson of the guidelines Task Force and head of the Cardiology Department, Geneva University Hospital, Switzerland. "Statins have very few side-effects. These include an increased risk of developing diabetes, and they may rarely cause myopathy. But the benefits of statins greatly outweigh their hazards, even among those at low risk of atherosclerotic CVD."
However, statins are not recommended in pre-menopausal women considering pregnancy or not using adequate contraception. "Although these drugs have not been shown to cause fetal malformations when unintentionally used in the first trimester of pregnancy, women needing a statin should avoid them during any period when they might conceive, as no formal study to address this question has been performed," said Prof Catapano.
The evidence for statin therapy is more limited in patients over 75, though is still consistent with a benefit. The guidelines advise taking level of risk, baseline LDL cholesterol, health status, and the risk of drug interactions into account when deciding whether statins are appropriate in those aged 75 or over.
Revisions have been made to the risk stratification categories so that patients with atherosclerotic CVD, diabetes with target organ damage, familial hypercholesterolemia,and severe chronic kidney disease are all categorized as very high-risk (and so will be offered intensive LDL-lowering therapy). Treatment goals for a particular risk category apply regardless of whether or not patients have had a heart attack or stroke.
Evidence since the 2016 guidelines suggests that raised Lp(a) is a cause of atherosclerotic CVD, and patients with genetically elevated Lp(a) can have similar lifetime risk of heart attack or stroke as those with familial hypercholesterolemia. Since Lp(a) is largely genetically determined, the guidelines recommend measuring it at least once in adulthood. "Assessment should be around 40 years of age to identify people before they have a heart attack or stroke," said Prof Baigent.
Fish oil supplements (particularly icosapent ethyl) are recommended, in combination with a statin, for patients with hypertriglyceridaemia despite statin treatment. In these patients, supplements reduce the risk of atherosclerotic CVD events, including heart attack and stroke, by about one quarter.
The guidelines advocate a lifetime approach to cardiovascular risk. This means that people of all ages and risk levels should be encouraged to adopt and sustain a healthy lifestyle. "The main requirements are healthy diet, avoidance of cigarette smoking, and regular exercise," said Prof Mach."There is no evidence that fish oil supplements prevent first heart attacks and strokes, so we did not recommend them for healthy people."

We can identify 'bad' genes. Why can't we use CRISPR gene editing to get rid of them? | Genetic Literacy Project

We can identify 'bad' genes. Why can't we use CRISPR gene editing to get rid of them? | Genetic Literacy Project

Genetic Literacy Project

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We can identify ‘bad’ genes. Why can’t we use CRISPR gene editing to get rid of them?

19-07-31 Press Release Portal Template

19-07-31 Press Release Portal Template

Another trick up the immune system’s sleeve: regrowing blood vessels
"Treating ischemia via recruitment of antigen-specific T cells"
Science Advances, July 31, 2019

‘Bone in a dish’ opens new window on cancer initiation, metastasis, bone healing | OHSU News

‘Bone in a dish’ opens new window on cancer initiation, metastasis, bone healing | OHSU News

‘Bone in a dish’ opens new window on cancer initiation, metastasis, bone healing

Like real bone, the material developed at OHSU has a 3D mineral structure populated with living cells, providing a unique model to study bone function, diseases, regeneration

Study identifies protein responsible for mechanism behind bone loss | UCLA Dentistry

Study identifies protein responsible for mechanism behind bone loss | UCLA Dentistry

STUDY IDENTIFIES PROTEIN RESPONSIBLE FOR MECHANISM BEHIND BONE LOSS

Posted on: Wednesday, 08/07/2019
FINDINGS
Researchers from the UCLA School of Dentistry have provided insight into how the mechanical process of bone loss works and have also identified a protein that is responsible for recycling of the cells that can also promote bone loss. The team showed that by eliminating a key protein responsible for the activation of bone loss, there is the potential to control the level of bone loss a person would develop.

High-sugar intake worsens autoimmune disease in mice | National Institutes of Health (NIH)

High-sugar intake worsens autoimmune disease in mice | National Institutes of Health (NIH)

National Institutes of Health (NIH) - Turning Discovery into Health

High-sugar intake worsens autoimmune disease in mice

At a Glance

  • In mouse models of autoimmune disorders, drinking sugary water worsened disease by activating inflammatory immune cells.
  • The findings suggest that a low-sugar diet may help prevent or treat autoimmune diseases such as Crohn’s disease and multiple sclerosis.
Sections of mouse colon tissueIn mouse models of Crohn’s disease, drinking sugary water led to more severe destruction of colon tissue (dark purple in image on bottom), compared to mice that drank normal water (top).Wanjun Chen, NIDCR
In recent decades, people in Western countries have been eating more food that is high in sugar, salt, and fat. Experts think that diet may play a role in autoimmune diseases, which have also become more common in the West.
Autoimmune diseases arise when the immune system mistakenly attacks normal tissues in the body. This response causes inflammation and gradual destruction of tissues. For example, in Crohn’s disease, immune cells target the intestine. In multiple sclerosis, the immune system eats away at the protective covering of nerves.
Scientists don’t have a clear idea of what causes autoimmunity, but some clues point to the role of diet. High-salt intake promotes inflammation and worsens disease in animal models of multiple sclerosis.
To explore whether sugar affects autoimmunity, researchers led by Dr. Wanjun Chen from NIH’s National Institute of Dental and Craniofacial Research (NIDCR) studied mice with T cell-transfer colitis—a mouse model of Crohn’s disease—and autoimmune encephalomyelitis—a model of multiple sclerosis. Results were published online on August 23, 2019, in Immunity.
The researchers gave some of the mice regular water, while others received sugar-sweetened water at a dose similar to sugary drinks consumed by humans. Compared to regular water, drinking sugary water worsened disease in both mouse models.
High sugar intake led to increased levels of an inflammatory immune cell called Th17 in and around the colons of mice with colitis and in the spinal cords and brains of mice with autoimmune encephalomyelitis. Th17 cells are believed to play a role in tissue destruction in autoimmune diseases including Crohn’s disease and multiple sclerosis.
To find out how sugar promotes Th17 cell activation, the scientists examined the behavior of immune cells grown in the lab. Sugar appeared to trigger the activation of a molecule called transforming growth factor-β (TGF-β). TGF-β, in turn, boosted levels of Th17 cells. Blocking TGF-β in the presence of sugar completely stopped production of Th17 cells. The scientists observed a similar pattern in the mice with colitis.
Further experiments revealed that TGF-β, which is normally in an inactive state, becomes activated in the presence of sugar via small chemicals called reactive oxygen species (ROS). Environmental pollutants, tobacco smoke, radiation, certain drugs, and other agents can trigger production of ROS. Too much ROS can damage the body.
“We discovered a previously unrecognized mechanism by which high-sugar intake stimulates Th17 cell production and worsens autoimmunity in mice through ROS-driven activation of TGF-β,” says Chen. “The findings can inform research into whether a low-sugar diet could help prevent or treat certain autoimmune diseases, including Crohn’s disease and multiple sclerosis.”
—by Catherine Evans, Ph.D.

Related Links

References: High glucose intake exacerbates autoimmunity through reactive oxygen species-mediated TGF-β cytokine activation.(link is external) Zhang D, Jin W, Wu R, Li J, Park S-A, Tu E, Zanvit P, Xu J, Liu O, Cain A, Chen W. Immunity. 2019 Aug 23. pii: doi: [Epub ahead of print].
Funding: NIH’s National Institute of Dental and Craniofacial Research (NIDCR).