News Briefs – February 2017

OMEGA-3s LOWER BLOOD PRESSURE IN YOUNG ADULTS

A study has found that healthy young people may be able to help prevent the onset of high blood pressure by eating diets rich in omega-3 fatty acids. (Omega-3s are essential fats, mostly found in fish and some types of plant oils.)

Researchers studied 2,036 young, healthy adults by measuring the amount of omega-3 fatty acids in their blood and recording their blood pressure measurements. They divided the participants into four groups, from the quarter with the highest amount of omega-3 fatty acids in their blood to the quarter with the lowest. They found that adults in the highest quarter had about 4 mm Hg lower systolic (upper number) and 2 mm Hg lower diastolic (lower number) blood pressure compared to those with the least omega-3 fatty acids in their blood. In general, the higher the omega-3 fatty acids in the blood, the lower both systolic and diastolic blood pressure. This suggests that promoting diets rich in omega-3 foods could become a strategy to prevent high blood pressure.

This study was presented in New Orleans at the American Heart Association Scientific Sessions 2016. It should be viewed as preliminary until it is published in a peer-reviewed journal.

DID YOU KNOW…?

Obesity is a well-established and strong risk factor for cancer, but according to a recent report, 75% of people are unaware of this link.

HIGH-DOSE VITAMIN D REDUCES RESPIRATORY INFECTIONS IN ELDERLY

Researchers have found that high doses of vitamin D reduce the incidence of acute respiratory illness (ARI) in older, long-term care residents. The findings of this clinical trial could help reduce a leading cause of serious illness, debilitation, and death among patients in nursing homes.

After studying 107 patients with an average age of 84 for one year, scientists found a 40% reduction in acute respiratory illness among those who took higher doses of vitamin D, which appears to have improved the capacity of the immune system to fight infections by bolstering its first line of defense. This in turn can prevent illnesses such as pneumonia, influenza and bronchitis, as well as exacerbations of chronic obstructive pulmonary diseases (COPD) such as emphysema.

The high-dose volunteers took 100,000 IU (international units) of vitamin D once a month (equivalent to an average daily intake of 3,300-4,300 IU), and the low-dose group took the more common dose of 400-1,000 IU each day. Antibiotics do not work on viral respiratory infections.

The study is not definitive proof that vitamin D can prevent ARIs, but if validated in further studies, vitamin D could cut these potentially deadly infections almost in half for this vulnerable group. However, high-dose vitamin D might be better provided in equal daily doses, because the team found that once-monthly doses slightly increased the risk of falls.

This study was posted November 16, 2016 on the site of the Journal of the American Geriatrics Society. It can be accessed at https://tinyurl.com/zcty6af for a fee.

SHOCK FINDING: RUNNING REDUCES KNEE INFLAMMATION, OSTEOARTHRITIS

New research has found that, contrary to normal assumption, running or jogging does not increase inflammation in the knees and in fact, decreases inflammation, which appears to forestall osteoarthritis of the knee. Pro-inflammatory molecules actually go down in the knee joint after running, reducing joint inflammation, which flies in the face of intuition, commented the study author. (Osteoarthritis, commonly affecting the knees, affects about 27 million people in the U.S.)

The researchers measured inflammation markers in the knee-joint fluid of several healthy men and women, aged 18 – 35, both before and after running. They found that the specific two inflammation markers they were looking for in the extracted (synovial) fluid, which are called GM-CSF and IL-15, decreased in concentration in the subjects after 30 minutes of running.

This suggests that running creates an anti-inflammatory environment that may be chondroprotective, meaning that it may help delay the onset of joint degenerative diseases such as osteoarthritis. Instead of causing inflammation and triggering or aggravating knee osteoarthritis, the study author suggested that running appears to act as a type of anti-inflammatory medicine.

This study was published in the December 2016 issue of the European Journal of Applied Physiology. The full report can be accessed at https://tinyurl.com/glkkt7m for a fee.

DIETARY MAGNESIUM LOWERS RISK OF STROKE, CHD, AND DIABETES

Scientists report that a diet rich in magnesium may reduce the risk of disease, including coronary heart disease, stroke, and Type 2 diabetes. The new meta-analysis of 40 published studies is the largest to date and included data on over one million individuals across nine countries, collected over 17 years. (Magnesium is vital for biological functions, including glucose metabolism, protein production, and synthesis of nucleic acids such as DNA. Diet is the main source of magnesium, including spices, nuts, beans, cocoa, whole grains, and green leafy vegetables. Guidelines recommend 300 mg daily for men and 270 mg for women, but between 2.5 and 15% of the general population are deficient.)

People in the highest category of dietary magnesium consumption had a 10% lower risk of coronary heart disease, 12% lower risk of stroke, and a 26% lower risk of Type 2 diabetes, compared to those with the lowest dietary intake. An extra 100 mg of dietary magnesium daily was linked to a 7% reduction in stroke risk and a 19% reduction in Type 2 diabetes risk.

This study was published in the December 8, 2016 issue of the journal BMC Medicine. The full-text version can be accessed now at https://tinyurl.com/hbldmf4 free of charge.

PROBIOTICS MAY BE KEY TOCONTROLLING AUTOIMMUNE DISORDERS

Scientists have found that defects in certain immune cells alter the type of bacteria living in the gut, which in turn appear to trigger some autoimmune disorders. These immune cells are known as regulatory T cells, or T reg cells. Replacing the missing bacteria may constitute a treatment for autoimmune disorders, the study suggests. (Normally, T reg cells suppress the immune system and prevent it from mistakenly attacking the healthy tissues of the body. Defects in these regulatory cells can thus lead to various types of autoimmune disease.)

Mice carrying a mutant version of a particular gene (the Foxp3 gene) were shown to exhibit changes in their gut bacteria microbiome around the same time that they developed symptoms of an inflammatory autoimmune disorder (IPEX syndrome) that results in eczema, Type I diabetes, and early death. These mice had lower levels of bacteria from the genus Lactobacillus. By feeding the mice the bacterial strain Lactobacillus reuteri, the team found that they could reset the gut bacterial community and reduce the levels of inflammation. This significantly extended the life span of the mice. The study author suggested that Lactobacillus reuteri supplements can be used therapeutically to control autoimmunity that is triggered by defective T cells.

This study was posted December 19, 2016, ahead of publication in the Journal of Experimental Medicine. The report is available at https://tinyurl.com/h6y5l6f with access fee.

HIGH-DOSE VITAMIN D IMPROVES SYMPTOMS OF AUTISM

Scientists have reported that high-dose vitamin D supplementation has improved the symptoms of children with autism spectrum disorder (ASD), without negative effects. (Autism spectrum disorder, or ASD, is a neurodevelopmental disorder that impairs the ability to communicate and interact with others and includes restricted repetitive behaviours, interests, and activities. Earlier studies found that there is vitamin D deficiency in autistic children.) In this double-blinded, clinical trial, the study team enlisted 109 children, aged three to ten, with ASD and randomized them into two groups. One group received a placebo and the other group received 300 IU (International Units) of vitamin D3 per kilogram of body weight per day to a maximum total of 5,000 IU per day per person.

To assess vitamin D status, the serum levels of 25-hydroxycholecalciferol (25 (OH)D), an indicator of vitamin D in the body, were measured at the beginning and again, after four months. In the treatment group, autism symptoms, such as hyperactivity, social withdrawal, and others, improved very significantly, but not in the placebo group. Dosages this high were tolerated in the trial for four months, but may or may not involve longer-term risks. Many additional studies of larger groups are needed to validate the efficacy and safety of vitamin D in ASD.

This study was first released online November 21, 2016 by the Journal of Child Psychology and Psychiatry. The report can be accessed at https://tinyurl.com/h3dx5je.

SLEEP DEPRIVATION DAMAGES HEART FUNCTION

Scientists have concluded that short-term sleep deprivation can lead to significant heart function damage, including cardiac contractility, blood pressure, and heart rate. (People who work in emergency medical services, medical residencies, and other high-stress jobs are often called upon to work 24-hour shifts with little opportunity for sleep. It is known that extreme fatigue can affect many physical, cognitive and emotional processes, but this is the first study to examine how working a 24-hour shift affects cardiac function.)

For the study, the team recruited 19 men and one woman, with a mean age of 31.6 years. Each participant underwent cardiovascular magnetic resonance (CMR) imaging before and after a 24-hour shift with an average of three hours of sleep. Blood and urine samples were collected and blood pressure and heart rate were measured.

Following short-term sleep deprivation, the participants showed significant increases in mean systolic blood pressure (from 112.8 to 118.5), in diastolic blood pressure (from 62.9 to 69.2), and heart rate (from 63.0 to 68.9). They had significant increases in levels of thyroid stimulating hormone (TSH) and cortisol, a hormone released by the body in response to stress. Long-term effects were not studied. Participants were not permitted to consume caffeine or food and beverages containing theobromine, a stimulant.

This study was presented in Chicago on December 2, 2016 at the annual meeting of the Radiological Society of North America (RSNA). It has not yet been journal-published.

PRACTISING YOGA REDUCES BLOOD PRESSURE

Research has found that blood pressure is lowered in people with pre-hypertension if they practice hatha yoga. (Pre-hypertension and high blood pressure increase the risk of heart attack, stroke, and heart failure.) Sixty people in their 50s who had pre-hypertension but were otherwise healthy were randomly assigned to either practice hatha yoga while also making conventional lifestyle changes, or to make lifestyle changes alone. These changes included moderate aerobic exercise, eating a healthier diet, and quitting smoking.

The yoga group received hatha yoga instruction for a month and then practised it at home. This included stretching, breathing exercises, and meditation for one hour daily. The average age of the control group participants was 52. After three months, the yoga group showed an average 24-hour decrease in systolic blood pressure of 4.9 mm Hg and a decrease in diastolic of 4.5 mm Hg, while there was no significant change in the control group. (These numbers seem modest, but even a 2 mm Hg decrease in diastolic blood pressure can reduce risk of stroke 15%.) The report recommended that patients with pre-hypertension practice hatha yoga for one hour daily.

These findings were presented December 7, 2016 in Kochi at the annual meeting of the Cardiological Society of India and should be considered preliminary until published in a peer-reviewed journal.

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