Exposure to second-hand smoke down in India, but remains major concern – Here are survey details

Colorado, Jul 24: A new study has found that physical stress in one's job may be associated with faster brain ageing and poorer memory.

Aga Burzynska, an assistant professor in the Department of Human Development and Family Studies, and her research team connected occupational survey responses with brain-imaging data from 99 cognitively normal older adults, age 60 to 79. They found that those who reported high levels of physical stress in their most recent job had smaller volumes in the hippocampus and performed poorer on memory tasks. The hippocampus is the part of the brain that is critical for memory and is affected in both normal ageing and in dementia.

Their findings were published this summer in Frontiers in Human Neuroscience under the research topic 'Work and Brain Health Across the Lifespan.'

"We know that stress can accelerate physical ageing and is the risk factor for many chronic illnesses," Burzynska said. "But this is the first evidence that occupational stress can accelerate brain and cognitive ageing."

She added that it is important to understand how occupational exposures affect the ageing of our brains.

"An average American worker spends more than eight hours at work per weekday, and most people remain in the workforce for over 40 years," Burzynska said. "By pure volume, occupational exposures outweigh the time we spend on leisure social, cognitive and physical activities, which protect our ageing minds and brains."

Physical demands at work

Burzynska explained that the association between "physical stress" and brain/memory were driven by physical demands at work. These included excessive reaching, or lifting boxes onto shelves, not necessarily aerobic activity. This is important because earlier work by Burzynska and her colleagues showed that leisure aerobic exercise is beneficial for brain health and cognition, from children to very old adults. Therefore, the researchers controlled for the effects of leisure physical activity and exercise.

As expected, leisure physical activity was associated with greater hippocampal volume, but the negative association with physical demands at work persisted.

"This finding suggests that physical demands at work may have parallel yet opposing associations with brain health," Burzynska explained. "Most interventions for postponing cognitive decline focus on leisure, not on your job. It's kind of unknown territory, but maybe future research can help us make some tweaks to our work environment for long-term cognitive health."

She added that the results could have important implications for society.

"Caring for people with cognitive impairment is so costly, on economic, emotional and societal levels," Burzynska said. "If we can support brain health earlier, in middle-aged workers, it could have an enormous impact."

The researchers considered and corrected for several other factors that could be related to work environment, memory and hippocampus, such as age, gender, brain size, educational level, job title, years in the occupation and general psychological stress.

One piece of the puzzle

"The research on this topic is so fragmented," Burzynska said. "One previous study linked mid-life managerial experience with greater hippocampus volume in older age. Another showed that taxi drivers had larger hippocampi than a city's bus drivers, presumably due to the need to navigate. In our study, job complexity and psychological stress at work were not related to hippocampal volume and cognition. Clearly, our study is just one piece of the puzzle, and further research is needed."

The magnetic resonance imaging (MRI) data used for the study was collected at the University of Illinois Urbana-Champaign between 2011 and 2014.

CSU researchers now can collect MRI data with the new 3T scanner at the University's Translational Medicine Institute.

With this new capability, Burzynska, along with Michael Thomas and Lorann Stallones of CSU's Department of Psychology, is launching a new project, "Impact of Occupational Exposures and Hazards on Brain and Cognitive Health Among Aging Agricultural Workers," which will involve collecting MRI brain scans and identifying risk and protective factors that could help the agricultural community age successfully. The project recently obtained funding as an Emerging Issues Short-Term Project from the High Plains Intermountain Center for Agricultural Health and Safety.

The Department of Human Development and Family Studies is part of CSU's College of Health and Human Sciences.

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.

Washington D.C., May 9: Do the middle age feel much stressful now, and seems to have changed over time, if compared to the life in the 90s? Well, this recent study indicates that it might be true.

The study has signalled to the fact that life may become more stressful majorly for middle-aged people than it was in the 1990s. The researchers reached this analysis even before the novel coronavirus started sweeping the globe.

A team of researchers led by Penn State found that across all ages, there was a slight increase in daily stress in the 2010s compared to the 1990s. But when researchers restricted the sample to people between the ages of 45 and 64, there was a sharp increase in daily stress.

"On average, people reported about 2 percent more stressors in the 2010s compared to people in the past," said David M. Almeida, professor of human development and family studies at Penn State.

"That's around an additional week of stress a year. But what really surprised us is that people at mid-life reported a lot more stressors, about 19 percent more stress in 2010 than in 1990. And that translates to 64 more days of stress a year."

Almeida said the findings were part of a larger project aiming to discover whether health during the middle of Americans' lives has been changing over time.

"Certainly, when you talk to people, they seem to think that daily life is more hectic and less certain these days," Almeida said.

For the study, the researchers collected data from 1,499 adults in 1995 and 782 different adults in 2012.

Almeida said the goal was to study two cohorts of people who were the same age at the time the data was collected but born in different decades. All study participants were interviewed daily for eight consecutive days.

During each daily interview, the researchers asked the participants about their stressful experiences throughout the previous 24 hours.

They asked questions related to arguments with family or friends or feeling overwhelmed at home or work, so and so. The participants were also asked how severe their stress was and whether those stressors were likely to impact other areas of their lives.

"We were able to estimate not only how frequently people experienced stress, but also what those stressors mean to them," Almeida said.

"For example, did this stress affect their finances or their plans for the future. And by having these two cohorts of people, we were able to compare daily stress processes in 1990 with daily stress processes in 2010," Almeida added.

After analyzing the data, the researchers found that participants reported significantly more daily stress and lower well-being in the 2010s compared to the 1990s.

Additionally, participants reported a 27 percent increase in the belief that stress would affect their finances and a 17 percent increase in the belief that stress would affect their future plans.

Almeida said he was surprised not that people were more stressed now than in the 90s, but at the age group that was mainly affected.

"We thought that with economic uncertainty, life might be more stressful for younger adults. But we didn't see that. We saw more stress for people at mid-life," Almeida said.

"And maybe that's because they have children who are facing an uncertain job market while also responsible for their own parents. So it's this generational squeeze that's making stress more prevalent for people at mid-life," he concluded.