Fat around blood vessels may keep them healthy: Study

Boston, Feb 4: Practising yoga may increase levels of a messenger molecule involved in regulating brain activity, and completing one yoga class per week may maintain elevated levels of this chemical, according to a study which may lead to better ways of mitigating depressive symptoms.

The study, published in the Journal of Alternative and Complementary Medicine, assessed a group of 30 clinically depressed patients who were randomly divided into two groups.

According to the researchers, including those from Boston University in the US, both groups engaged in coherent breathing, and Iyengar yoga -- a form of hatha yoga, developed by B. K. S. Iyengar, emphasising on detail, precision, and alignment in the performance of yoga postures.

The only difference between the groups, the scientists said, was the number of 90 minute yoga sessions, and home sessions in which each group participated.

Over three months, they said, the high-dose group (HDG) was assigned three sessions per week, while the low-intensity group (LIG) engaged in two sessions per week.

The participants underwent magnetic resonance imaging (MRI) scans of their brain before the first and after the last yoga session, and also completed a clinical depression scale to monitor their symptoms, the study noted.

Results of the study revealed that both groups had improvement in depressive symptoms after three months.

Their MRI analysis showed that levels of the brain messenger molecule GABA were elevated after three months of yoga, as compared to the levels before starting yoga.

According to the study, this increase was found for approximately four days after the last yoga session, but the rise was no longer observed after about eight days.

"The study suggests that the associated increase in GABA levels after a yoga session are 'time-limited' similar to that of pharmacologic treatments such that completing one session of yoga per week may maintain elevated levels of GABA," explained study co-author Chris Streeter from Boston University.

Providing evidence-based data may help in getting more individuals to try yoga as a strategy for improving their health and well-being, the scientists said.

"A unique strength of this study is that pairing the yoga intervention with brain imaging provides important neurobiological insight as to the 'how' yoga may help to alleviate depression and anxiety," said study co-author Marisa Silveri from Harvard University.

In this study, we found that an important neurochemical, GABA, which is related to mood, anxiety, and sleep, is significantly increased in association with a yoga intervention," Silveri said.

Apart from the many benefits of doing exercise, new research has now found that exercise can slow down or prevent the development of macular degeneration and may benefit other common causes of vision loss, such as glaucoma and diabetic retinopathy.

The new study from the University of Virginia School of Medicine found that exercise reduced the harmful overgrowth of blood vessels in the eyes of lab mice by up to 45 per cent. This tangle of blood vessels is a key contributor to macular degeneration and several other eye diseases.

The study represents the first experimental evidence showing that exercise can reduce the severity of macular degeneration, a leading cause of vision loss, the scientists report. Ten million Americans are estimated to have the condition.

"There has long been a question about whether maintaining a healthy lifestyle can delay or prevent the development of macular degeneration. The way that question has historically been answered has been by taking surveys of people, asking them what they are eating and how much exercise they are performing," said researcher Bradley Gelfand, PhD, of UVA's Center for Advanced Vision Science.

"That is basically the most sophisticated study that has been done. The problem with that is that people are notoriously bad self-reporters ... and that can lead to conclusions that may or not be true. This [study] offers hard evidence from the lab for the very first time," Gelfand added.

Enticingly, the research found that the bar for receiving the benefits from exercise was relatively low - more exercise didn't mean more benefit.

"Mice are kind of like people in that they will do a spectrum of exercise. As long as they had a wheel and ran on it, there was a benefit. The benefit that they obtained is saturated at low levels of exercise," Gelfand said.

An initial test comparing mice that voluntarily exercised versus those that did not found that exercise reduced the blood vessel overgrowth by 45%. A second test, to confirm the findings, found a reduction of 32 per cent.

The scientists aren't certain exactly how exercise is preventing the blood vessel overgrowth. There could be a variety of factors at play, they say, including increased blood flow to the eyes.

Gelfand, of UVA's Department of Ophthalmology and Department of Biomedical Engineering, noted that the onset of vision loss is often associated with a decrease in exercise.

"It is fairly well known that as people's eyes and vision deteriorate, their tendency to engage in physical activity also goes down. It can be a challenging thing to study with older people. ... How much of that is one causing the other?" he said.
The researchers already have submitted grant proposals in hopes of obtaining funding to pursue their findings further.

"The next step is to look at how and why this happens, and to see if we can develop a pill or method that will give you the benefits of exercise without having to exercise," Gelfand said.

He explained, "We're talking about a fairly elderly population [of people with macular degeneration], many of whom may not be capable of conducting the type of exercise regimen that may be required to see some kind of benefit." (He urged people to consult their doctors before beginning any aggressive exercise program.)
Gelfand, a self-described couch potato, disclosed a secret motivation for the research: "One reason I wanted to do this study was sort of selfish. I was hoping to find some reason not to exercise," he joked. "It turned out exercise really is good for you."

UN, Jul 14: There will be no return to the "old normal" for the foreseeable future as a result of the ongoing COVID-19 pandemic, and too many countries were still headed in the wrong direction, the chief of the World Health Organization (WHO) warned.

"The virus remains public enemy number one, but the actions of many governments and people do not reflect this," Xinhua news agency quoted WHO Director-General Tedros Adhanom Ghebreyesus at as saying a regular briefing on Monday.

He noted that mixed messages from leaders are undermining trust, which is the most critical ingredient of any response, while the only aim of the virus is to find people to infect.

Things are going to "get worse and worse and worse", he warned, unless governments communicate clearly with their citizens and roll out a comprehensive strategy focused on suppressing transmission and saving lives, while populations follow the basic public health principles of physical distancing, hand washing, wearing masks, coughing etiquette and staying home when sick.

COVID-19 has been gaining its momentum lately.

According to Tedros, Sunday saw a record of 230,000 cases reported to WHO, of which almost 80% were from just 10 countries and about half from just two countries.

"But it does not have to be this way," he said, asking every single leader, government and individual "to do their bit to break the chains of COVID-19 transmission and end the collective suffering".

To control the disease and get on with people's lives, Tedros said, three things are required. The first is to focus on reducing mortality and suppressing transmission; the second is to focus on an empowered, engaged community that takes individual behaviour measures in the interest of each other.

And the third is a strong government leadership and coordination of comprehensive strategies that are communicated clearly and consistently.

"We weren't prepared collectively, but we must use all the tools we have to bring this pandemic under control. And we need to do it right now," he added.

At the WHO briefing on Monday, health experts also said there was evidence to suggest that children under the age of 10 were only very mildly affected by Covid-19, while those over 10 seemed to suffer similar mild symptoms to young adults.

To what extent children can transmit the virus, while it appears to be low, remains unknown.

On Tuesday, the number of global coronavirus cases cross the 13 million mark, according to the Johns Hopkins University.

The total number of cases currently stood at 13,070,097, while the fatalities rose to 572,411, the University's Center for Systems Science and Engineering (CSSE) revealed in its latest update.

The US accounted for the world's highest number of infections and fatalities at 3,363,056 and 135,605, respectively, according to the CSSE.

Brazil came in the second place with 1,884,967 infections and 72,833 deaths.