Intensity of light may influence spending behaviour: study

High-protein diets may help people lose weight and build muscle, but there is a downside to it --a greater heart attack risk. Researchers now report that high-protein diets boost artery-clogging plaque.

The research in mice showed that high-protein diets spur unstable plaque -- the kind most prone to rupturing and causing blocked arteries.

More plaque buildup in the arteries, particularly if it's unstable, increases the risk of heart attack.

"There are clear weight-loss benefits to high-protein diets, which has boosted their popularity in recent years," said senior author Babak Razani, associate professor at Washington University School of Medicine in St. Louis, Missouri.

"But animal studies and some large epidemiological studies in people have linked high dietary protein to cardiovascular problems. We decided to take a look at whether there is truly a causal link between high dietary protein and poorer cardiovascular health," Razani added.

The researchers studied mice who were fed a high-fat diet to deliberately induce atherosclerosis, or plaque buildup in the arteries.

Some of the mice received a high-fat diet that was also high in protein. And others were fed a high-fat, low-protein diet for comparison.

The mice on the high-fat, high-protein diet developed worse atherosclerosis -- about 30 per cent more plaque in the arteries -- than mice on the high-fat, normal-protein diet, despite the fact that the mice eating more protein did not gain weight, unlike the mice on the high-fat, normal-protein diet.

"A couple of a scoop of protein powder in a milkshake or smoothie adds something like 40 grams of protein -- almost equivalent to the daily recommended intake," Razani said.

"To see if protein has an effect on cardiovascular health, we tripled the amount of protein that the mice receive in the high-fat, high-protein diet -- keeping the fat constant. Protein went from 15 per cent to 46 per cent of calories for these mice".

Plaque contains a mix of fat, cholesterol, calcium deposits and dead cells. Past work by Razani's team and other groups has shown that immune cells called macrophages work to clean up plaque in the arteries.

But the environment inside plaque can overwhelm these cells, and when such cells die, they make the problem worse, contributing to plaque buildup and increasing plaque complexity.

"In mice on the high-protein diet, their plaques were a macrophage graveyard," Razani informed.

To understand how high dietary protein might increase plaque complexity, Razani and his colleagues also studied the path protein takes after it has been digested -- broken down into its original building blocks, called amino acids.

"This study is not the first to show a telltale increase in plaque with high-protein diets, but it offers a deeper understanding of the impact of high protein with the detailed analysis of the plaques," said Razani.

"This work not only defines the critical processes underlying the cardiovascular risks of dietary protein but also lays the groundwork for targeting these pathways in treating heart disease," he added.

Toronto, Feb 4: People who text while walking face a higher risk of an accident than those listening to music or talking on the phone, a study has found.

The study, published in the journal Injury Prevention, found that smartphone texting is linked to compromised pedestrian safety, with higher rates of 'near misses', and failure to look left and right before crossing a road.

Researchers from the University of Calgary in Canada call for a more thorough approach to exploring the impact of distracted pedestrian behaviours on crash risk.

Worldwide, around 270,000 pedestrians die every year, accounting for around a fifth of all road traffic deaths, according to the researchers.

'Pedestrian distraction' has become a recognised safety issue as more and more people use their smartphones or hand held devices while walking on the pavement and crossing roads, they said.

The researchers looked for published evidence to gauge the potential impact on road safety of hand-held or hands-free device activities.

This included talking on the phone, text messaging, browsing and listening to music.

From among 33 relevant studies, they pooled the data from 14 -- involving 872 people -- and systematically reviewed the data from another eight.

The analysis showed that listening to music wasn't associated with any heightened risk of potentially harmful pedestrian behaviours.

Talking on the phone was associated with a small increase in the time taken to start crossing the road, and slightly more missed opportunities to cross the road safely.

The researchers found that text messaging emerged as the potentially most harmful behaviour.

It was associated with significantly lower rates of looking left and right before or while crossing the road, and with moderately increased rates of collisions, and close calls with other pedestrians or vehicles, they said.

Texting also affected the time taken to cross a road, and missed opportunities to cross safely, but to a lesser extent, according to the researchers.

The review of the eight observational studies revealed that the percentage of pedestrians who were distracted ranged from 12 to 45 per cent, they said.

It also found behaviours were influenced by several factors, including gender, time of day, solo or group crossing, and walking speed.

The researchers acknowledge "a variety of study quality issues" which limit the generalisability of the findings.

"Given the ubiquity of smartphones, social media, apps, digital video and streaming music, which has infiltrated most aspects of daily life, distracted walking and street cross will be a road safety issue for the foreseeable future," the researchers noted.

"And as signage and public awareness campaigns don't seem to alter pedestrian behaviour, establishing the relationship between distracted walking behaviour and crash risk is an essential research need," they said.

Despite tremendous advances in treatment of congenital heart disease (CHD), a new global study shows that the chances for a child to survive a CHD diagnosis is significantly less in low-income countries.

The research revealed that nearly 12 million people are currently living with CHD globally, 18.7 per cent more than in 1990.

The findings, published in The Lancet, is drawn from the first comprehensive study of congenital heart disease across 195 countries, prepared using data from the Global Burden of Diseases, Injuries and Risk Factors Study 2017 (GBD).

"Previous congenital heart estimates came from few data sources, were geographically narrow and did not evaluate CHD throughout the life course," said the study authors from Children's National Hospital in the US.

This is the first time the GBD study data was used along with all available data sources and previous publications - making it the most comprehensive study on the congenital heart disease burden to date.

The study found a 34.5 per cent decline in deaths from congenital disease between 1990 to 2017. Nearly 70 per cent of deaths caused by CHD in 2017 (180,624) were in infants less than one year old.

Most CHD deaths occurred in countries within the low and low-middle socio-demographic index (SDI) quintiles.

Mortality rates get lower as a country's Socio-demographic Index (SDI) rises, the study said.

According to the researchers, birth prevalence of CHD was not related to a country's socio-demographic status, but overall prevalence was much lower in the poorest countries of the world.

This is because children in these countries do not have access to life saving surgical services, they added.

"In high income countries like the United States, we diagnose some heart conditions prenatally during the 20-week ultrasound," said Gerard Martin from Children's National Hospital who contributed to the study.

"For children born in middle- and low-income countries, these data draw stark attention to what we as cardiologists already knew from our own work in these countries -- the lack of diagnostic and treatment tools leads to lower survival rates for children born with CHD," said researcher Craig Sable.

"The UN has prioritised reduction of premature deaths from heart disease, but to meet the target of 'ending preventable deaths of newborns and children under 5 years of age,' health policy makers will need to develop specific accountability measures that address barriers and improve access to care and treatment," the authors wrote.