Stress could harm your heart

PARIS: Scientists said Thursday they may have uncovered a biological explanation for the long suspected link between stress and heart disease.

People with a highly active amygdala -- a region of the brain involved in stress processing -- also have a higher risk of heart disease and stroke, the researchers revealed.

A hard-working amygdala was also linked to increased bone marrow activity and inflammation of the arteries, which may explain the higher heart disease and stroke risk, the team said.

The data suggested that stressed amygdala may send signals to the bone marrow to produce extra white blood cells, which may in turn cause arteries to narrow and become inflamed, causing cardiovascular problems.

The potential link "raises the possibility that reducing stress could produce benefits that extend beyond an improved sense of psychological wellbeing," said lead author Ahmed Tawakol of the Massachusetts General Hospital.

Published in The Lancet medical journal, the study entailed PET and CT scans of the brain, bone marrow and spleen activity, as well as artery inflammation, of 293 patients.

The group was surveyed for 3.7 years on average, during which time 22 suffered "cardiovascular events" -- including heart attack, heart failure, stroke and narrowing of arteries, said the study.

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

In a sub-study, 13 patients with a history of post-traumatic stress disorder were tested separately.

"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," the team found.

The amygdala are almond-shaped neuron clusters deep in the brain thought to regulate emotion, fear, anxiety, pleasure and stress.

Commenting on the study, Ilze Bot of Leiden University in the Netherlands said the data identified chronic stress "as a true risk factor" for cardiovascular diseases.

Given the increasing number of people suffering from job or social stress, doctors may have to include it when they assess an individual´s risk for cardiovascular disease, she said.

A 2014 study said chronic stress may trigger an overproduction of white blood cells which clump together on artery walls, restricting blood flow and encouraging clot-formation, to raise heart attack and stroke risk.

Source: The NEWS

Higher chances of developing dementia

LONDON: People living near major roads have a higher chance of developing dementia, according to a large-scale study published in British medical journal The Lancet on Thursday.

The research looked at six million adults living in Ontario, Canada between 2001 and 2012, and found that those living less than 50 metres (yards) from a busy road had a seven percent higher incidence of dementia.

The risk was four percent above normal for those living 50-100 metres from main roads and two percent higher among those 100-200 metres away.

There was no discernable elevated risk among people living more than 200 metres from a major route.

The study, led by Hong Chen from Public Health Ontario, found that long-term exposure to two common pollutants -- nitrogen dioxide (NO2) and fine particulates -- were associated with dementia but did not account for the full effect.

This suggested that other factors -- such as noise or other pollutants -- may play a contributing role.

The research did not establish any link between proximity to heavy traffic and other neurological conditions such as Parkinson´s Disease or multiple sclerosis.

According to the World Health Organization, 47.5 million people worldwide have dementia -- a syndrome marked by deterioration in memory, thinking, behaviour and the ability to perform everyday activities.

Some 7.7 million new cases of dementia are reported every year, with Alzheimer´s disease being the most common cause and contributing to 60-70% of cases.

Other causes of dementia include stroke and hypertension.

Pollution has long been suspected as playing a role in the development of Alzheimer´s disease but no clear link had been established until now.

"Our study suggests that busy roads could be a source of environmental stressors that could give rise to the onset of dementia," Hong said.

"Increasing population growth and urbanisation has placed many people close to heavy traffic, and with widespread exposure to traffic and growing rates of dementia, even a modest effect from near-road exposure could pose a large public health burden."

Source: The News