Exposure to outdoor air pollution is linked to decreased lung function and an increased risk of developing chronic obstructive pulmonary disease (COPD), according to a study of over 300,000 people published Tuesday.
COPD is a long-term condition linked to reduced lung function that causes inflammation in the lungs and a narrowing of the airways, making breathing difficult.
According to the Global Burden of Disease (GBD) project, COPD is the third leading cause of death worldwide, and the number of global COPD deaths are expected to increase over the next ten years.
Lung function normally declines as we age, but the research published in the European Respiratory Journal suggests that air pollution may contribute to the ageing process and adds to the evidence that breathing in polluted air harms the lungs.
“There are surprisingly few studies that look at how air pollution affects lung health,” said Anna Hansell, a professor at the University of Leicester, UK.
The researchers used a validated air pollution model to estimate the levels of pollution that people were exposed to at their homes when they enrolled in the UK Biobank study.
The types of pollutants the researchers investigated included particulate matter (PM10), fine particulate matter (PM2.5) and nitrogen dioxide (NO2), which are produced by burning fossil fuels from car and other vehicle exhausts, power plants and industrial emissions.
The team then conducted multiple tests to see how long-term exposure to higher levels of the different air pollutants was linked to changes to participants’ lung function.
The participants’ age, sex, body mass index (BMI), household income, education level, smoking status, and exposure to secondhand smoke were accounted for in the analyses.
Further analyses also looked at whether working in occupations that increase the risk of developing COPD impacted disease prevalence.
The data showed that for each annual average increase of five microgrammes per cubic metre of PM2.5 in the air that participants were exposed to at home, the associated reduction in lung function was similar to the effects of two years of ageing.
When the researchers assessed COPD prevalence, they found that among participants living in areas with PM2.5 concentrations above World Health Organization (WHO) annual average guidelines of ten microgrammes per cubic meter, COPD prevalence was four times higher than among people who were exposed to passive smoking at home, and prevalence was half that of people who have ever been a smoker.
The current EU air quality limits for PM2.5 is 25 microgrammes per cubic metre, which is higher than the levels that the researchers noted as being linked to reduced lung function.
“In one of the largest analyses to date, we found that outdoor air pollution exposure is directly linked to lower lung function and increased COPD prevalence.
“We found that people exposed to higher levels of pollutants had lower lung function equivalent to at least a year of ageing,” Hansell said.
“Worryingly, we found that air pollution had much larger effects on people from lower income households. Air pollution had approximately twice the impact on lung function decline and three times the increased COPD risk on lower-income participants compared to higher-income participants who had the same air pollution exposure.
“We accounted for participants’ smoking status and if their occupation might affect lung health, and think this disparity could be related to poorer housing conditions or diet, worse access to healthcare or long-term effects of poverty affecting lung growth in childhood,” Hansell said.
Cutting 300 calories in healthy adults known to improve heart health
If you think you don’t need to cut calories just because you have a few extra pounds or are healthy, then take note! Even in healthy adults cutting around 300 calories a day significantly improved already good levels of cholesterol, blood pressure, blood sugar, and other markers, suggests a study. The study was published in the journal ‘The Lancet Diabetes & Endocrinology’.
The trial, part of an ongoing project with the National Institutes of Health continues to build on the researchers’ hypothesis that it’s not just weight loss that leads to these improvements, but some more complex metabolic change triggered by eating fewer calories than what’s expended.
“There’s something about caloric restriction, some mechanism we don’t yet understand that results in these improvements. We have collected blood, muscle and other samples from these participants and will continue to explore what this metabolic signal or magic molecule might be,” said William E. Kraus, the study’s lead author.
For the first month of the trial, participants ate three meals a day that would cut one-fourth of their daily calories to help train them on the new diet. Participants were asked to maintain the 25 per cent calorie reduction for two years. Their ability to do that varied, with the average calorie reduction for all participants being about 12 per cent. Still, they were able to sustain a 10 per cent drop in their weight, 71 per cent of which was fat, the study found.
There were numerous improvements in markers that measure the risk of metabolic disease. After two years, participants also showed a reduction in a biomarker that indicates chronic inflammation which has also been linked to heart disease, cancer, and cognitive decline.
“This shows that even a modification that is not as severe as what we used in this study could reduce the burden of diabetes and cardiovascular disease. People can do this fairly easily by simply watching their little indiscretions here and there, or maybe reducing the amount of them, like not snacking after dinner,” said Kraus.
Just 20-minute ‘nature pill’ can lower your stress
Taking just 20 minutes out of your day to stroll or sit near nature will significantly lower your stress hormone levels, a new study suggests.
Healthcare practitioners can use this finding to prescribe ‘nature pills’ to have a real measurable effect, according to researchers from the University of Michigan.
“We know that spending time in nature reduces stress, but until now it was unclear how much is enough, how often to do it, or even what kind of nature experience will benefit us,” said lead author MaryCarol Hunter from the varsity.
For the study, published in the journal Frontiers in Psychology, the research team involved 36 participants. Over an eight-week period, they were asked to take a ‘nature pill’ for at least 10 minutes, three times a week.
Levels of cortisol — a stress hormone — were measured from saliva samples taken before and after taking the ‘nature pill’, once every two weeks.
The data revealed that just a 20 minute nature experience was enough to significantly reduce cortisol levels.
And if you take in a little more nature experience – 20 to 30 minutes sitting or walking – cortisol levels dropped at their greatest rate, the researchers said.
“Our study shows that for the greatest payoff, in terms of efficiently lowering levels of the stress hormone cortisol, you should spend 20 to 30 minutes sitting or walking in a place that provides you with a sense of nature,” Hunter noted.
Exercise can help in containing arthritis
A new study has found that degradation of cartilage due to osteoarthritis could be prevented with the help of exercise. The study, published in the journal Osteoarthritis and Cartilage, demonstrates the benefits of exercise on the tissues that form our joints.
The researchers have shown for the first time how mechanical forces experienced by cells in joints during exercise prevent cartilage degradation by suppressing the action of inflammatory molecules that cause osteoarthritis. During exercise, the cartilage in joints such as the hip and knee is squashed.
This mechanical distortion is detected by the living cells in the cartilage, which then block the action of inflammatory molecules associated with conditions such as arthritis. The researchers showed that this anti-inflammatory effect of physical activity is caused by activation of a particular protein, called HDAC6, which triggers changes in the proteins that form primary cilia.
Pharmaceutical drugs that blocked HDAC6 activation prevented the anti-inflammatory effects of physical activity, while other drug treatments were able to mimic the benefits of exercise. Changes in length of the primary cilia, which are only a few 1000th of a millimetre, provided a biomarker of the level of inflammation.
Cilia got longer during inflammation, but treatments that prevented this elongation successfully prevented inflammation. Su Fu, a PhD student at Queen Mary University of London and study author, said: “We have known for some time that healthy exercise is good for you. Now we know the process through which exercise prevents cartilage degradation.”
Professor Martin Knight, lead researcher of the study added, “These findings may also explain the anti-inflammatory effects of normal blood flow in arteries, which is important for preventing arterial diseases such as atherosclerosis and aneurysm.” The researchers hope that these findings will help in the search for treatments for arthritis. The researchers suggest the results may lead to a whole new therapeutic approach known as “mechanomedicine” in which drugs simulate the effect of mechanical forces to prevent the damaging effects of inflammation and treat conditions such as arthritis.