Stress may increase heart disease, stroke risk: study

January 12, 2017

London, Jan 12: People with heightened activity in the amygdala - a region of the brain involved in stress - may have a greater risk of heart disease and stroke, according to a study published in The Lancet journal today that may lead to new treatments for stress-related cardiovascular problems.

heartThe study provides new insights into the possible mechanism by which stress can lead to cardiovascular disease in humans, researchers said.

The researchers suggest that these findings could eventually lead to new ways to target and treat stress-related cardiovascular risk.

Smoking, high blood pressure and diabetes are well-known risk factors for cardiovascular disease and chronic psychosocial stress could also be a risk factor.

Previously, animal studies identified a link between stress and higher activity in the bone marrow and arteries, but it has remained unclear whether this applies to humans.

No previous study has identified the region of the brain that links stress to the risk of heart attack and stroke.

In this study, 293 patients were given a combined PET/CT scan to record their brain, bone marrow and spleen activity and inflammation of their arteries.

Patients were then tracked for an average of 3.7 years to see if they developed cardiovascular disease. In this time 22 patients had cardiovascular events including heart attack, angina, heart failure, stroke and peripheral arterial disease.

Those with higher amygdala activity had a greater risk of subsequent cardiovascular disease and developed problems sooner than those with lower activity, researchers said.

They also found that the heightened activity in the amygdala was linked to increased bone marrow activity and inflammation in the arteries, and suggest that this may cause the increased cardiovascular risk.

The researchers suggest a possible biological mechanism, whereby the amygdala signals to the bone marrow to produce extra white blood cells, which in turn act on the arteries causing them to develop plaques and become inflamed, which can cause heart attack and stroke.

In a small sub-study, 13 patients who had a history of PTSD also had their stress levels assessed by a psychologist, underwent a PET scan and had their levels of C-reactive protein - a protein that indicates levels of inflammation in the body - measured.

Those who reported the highest levels of stress had the highest levels of amygdala activity along with more signs of inflammation in their blood and the walls of their arteries.

"Our results provide a unique insight into how stress may lead to cardiovascular disease. This raises the possibility that reducing stress could produce benefits that extend beyond an improved sense of psychological wellbeing," said lead author Ahmed Tawakol from Massachusetts General Hospital and Harvard Medical School in the US.

"Eventually, chronic stress could be treated as an important risk factor for cardiovascular disease, which is routinely screened for and effectively managed like other major cardiovascular disease risk factors," said Tawakol.

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February 7,2020

Birmingham, Feb 7: According to a new study, social media users are more likely to eat healthy or junk food after getting influenced by their peer group.

The research published in the scientific journal 'Appetite' found that study participants ate an extra fifth of a portion of fruit and vegetables themselves for every portion they thought their social media peers ate. So, if they believed their friends got their 'five a day' of fruit and veg, they were likely to eat an extra portion themselves.

On the other hand, Facebook users were found to consume an extra portion of unhealthy snack foods and sugary drinks for every three portions they believed their online social circles did.
The findings suggested that people eat around a third more junk food if they think their friends also indulge in the same.

The Aston University researchers said the findings provide the first evidence to suggest our online social circles could be implicitly influencing our eating habits, with important implications for using 'nudge' techniques on social media to encourage healthy eating.

Researchers asked 369 university students to estimate the amount of fruit, vegetables, 'energy-dense snacks' and sugary drinks their Facebook peers consumed on a daily basis.

The information was cross-referenced with the participants' own actual eating habits and showed that those who felt their social circles 'approved' of eating junk food consumed significantly more themselves. Meanwhile, those who thought their friends ate a healthy diet ate more portions of fruit and veg. Their perceptions could have come from seeing friends' posts about the food and drink they consumed, or simply a general impression of their overall health.

There was no significant link between the participants' eating habits and their Body Mass Index (BMI), a standard measure of healthy weight, however. The researchers said the next stage of their work would track a participant group over time to see whether the influence of social media on eating habits had a longer-term impact on weight.

The most recent figures from the NHS's Health Survey for England showed that in 2018 only 28 percent of adults were eating the recommended five portions of fruit and vegetables per day. In Wales, this was 24 percent, in Scotland 22 percent and in Northern Ireland around 20 percent. Children and young people across the UK had even lower levels of fruit and veg consumption.

Aston University health psychology Ph.D. student Lily Hawkins, who led the study alongside supervisor Dr. Jason Thomas, said: "This study suggests we may be influenced by our social peers more than we realize when choosing certain foods. We seem to be subconsciously accounting for how others behave when making our own food choices. So if we believe our friends are eating plenty of fruit and veg we're more likely to eat fruit and veg ourselves. On the other hand, if we feel they're happy to consume lots of snacks and sugary drinks, it can give us a license to overeat foods that are bad for our health. The implication is that we can use social media as a tool to 'nudge' each other's eating behavior within friendship groups, and potentially use this knowledge as a tool for public health interventions."

"With children and young people spending a huge amount of time interacting with peers and influencers via social media, the important new findings from this study could help shape how we deliver interventions that help them adopt healthy eating habits from a young age and stick with them for life," said professor Claire Farrow.

A dietitian called Aisling Pigott further mentioned that "Research such as this demonstrates how we are influenced by online perceptions about how others eat. The promotion of positive health messages across social media, which are focused on promoting healthy choices and non-restrictive relationships with food and body, could nudge people into making positive decisions around the food they eat."

"We do have to be mindful of the importance of 'nudging' positive behaviors and not 'shaming' food choices on social media as a health intervention. We know that generating guilt around food is not particularly helpful when it comes to lifestyle change and maintenance," Aisling added.

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July 3,2020

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."

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May 20,2020

Washington D.C., May 20: While a dairy-rich diet is helpful in meeting the body's calcium requirement, outcomes of a large international study links eating at least two daily servings of dairy with lower risks of diabetes and high blood pressure.

The dairy-rich diet also proved to lower the cluster of factors that heighten cardiovascular disease risk (metabolic syndrome). The study was published online in journal BMJ Open Diabetes Research & Care.

The observed associations were strongest for full-fat dairy products, the findings indicated.

Previously published research has suggested that higher dairy intake is associated with a lower risk of diabetes, high blood pressure, and metabolic syndrome. But these studies have tended to focus on North America and Europe to the exclusion of other regions of the world.

To see whether these associations might also be found in a broader range of countries, the researchers drew on people taking part in the Prospective Urban Rural Epidemiology (PURE) study.

Participants were all aged between 35 and 70 and came from 21 countries: Argentina; Bangladesh; Brazil; Canada; Chile; China; Colombia; India; Iran; Malaysia; Palestine; Pakistan; Philippines, Poland; South Africa; Saudi Arabia; Sweden; Tanzania; Turkey; United Arab Emirates; and Zimbabwe.

Usual dietary intake over the previous 12 months was assessed by means of Food Frequency Questionnaires. Dairy products included milk, yogurt, yogurt drinks, cheese and dishes prepared with dairy products, and were classified as full or low fat (1-2 percent).

Butter and cream were assessed separately as these are not commonly eaten in some of the countries studied.

Information on personal medical history, use of prescription medicines, educational attainment, smoking and measurements of weight, height, waist circumference, blood pressure and fasting blood glucose were also collected.

Data on all five components of the metabolic syndrome were available for nearly 113,000 people: blood pressure above 130/85 mm Hg; waist circumference above 80 cm; low levels of (beneficial) high-density cholesterol (less than 1-1.3 mmol/l); blood fats (triglycerides) of more than 1.7 mmol/dl; and fasting blood glucose of 5.5 mmol/l or more.

Average daily total dairy consumption was 179 g, with full-fat accounting for around double the amount of low fat: 124.5+ vs 65 g.

Some 46, 667 people had metabolic syndrome--defined as having at least 3 of the 5 components.

Total dairy and full-fat dairy, but not low-fat dairy, was associated with a lower prevalence of most components of metabolic syndrome, with the size of the association greatest in those countries with normally low dairy intakes.

At least 2 servings a day of total dairy were associated with a 24 percent lower risk of metabolic syndrome, rising to 28 percent for full-fat dairy alone, compared with no daily dairy intake.

The health of nearly 190,000 participants was tracked for an average of nine years, during which time 13,640 people developed high blood pressure and 5351 developed diabetes.

At least 2 servings a day of total dairy was associated with a 11-12 percent lower risk of both conditions, rising to a 13-14 percent lower risk for 3 daily servings. The associations were stronger for full fat than they were for low-fat dairy.

This is an observational study, and as such can't establish the cause. Food frequency questionnaires are also subject to recall, and changes in metabolic syndrome weren't measured over time, all of which may have influenced the findings.

Nevertheless, the researchers suggest: "If our findings are confirmed in sufficiently large and long term trials, then increasing dairy consumption may represent a feasible and low-cost approach to reducing [metabolic syndrome], hypertension, diabetes, and ultimately cardiovascular disease events worldwide."

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