Science has long assumed that children living in cities grow up healthier and faster than those living in rural areas, but new research suggests that trend has reversed over the past two decades.Global study released Wednesday Nature In most countries, especially wealthy countries such as the United States, United Kingdom and France, the average height of urban children and adolescents aged 5 to 19 is slightly shorter than their rural peers. I understand.
“Historically there have been very clear advantages to living in cities, but those advantages have been over time,” said study co-author Honor Bixby, a Fellow for Population Health and Epidemiology Studies at the University of Essex, UK. “But that can be seen as a positive in that the rural elevations are really catching up.”
But researchers are trying to figure out exactly why this is happening.
Cities have long been associated with improved health. Researchers call this “urban dominance.” Residents of busy and advanced centers are more likely to have better access to quality health care, education, safety and nutrition, and barriers to these resources are especially important in children’s critical early development. Bixby, who worked on the study with more than 1,500 researchers in the Noncommunicable Disease Risk Factors Collaborative, a global network of scientists and physicians, said: really sets the tone for your health in adulthood and beyond.” “We are particularly interested in height and body mass index (BMI) as anthropometric measures of growth and development. [height and weight are] Not only the quality of nutrition is affected, but also the health of the living environment. (Some experts and the public have criticized the limitations of BMI, its overuse as an accurate measure of health, and its failure to capture inter-individual variability. However, Bixby says BMI can still be useful in estimating averages and trends (population level)
The study analyzed data of 71 million participants from 2,325 population surveys conducted in 200 countries and territories between 1990 and 2020. In 1990, urban children were taller than rural children, but the difference was very small in most high-income countries. However, by 2020, both urban and rural children generally increased in height, while urban children grew slower in most countries.
“It was height that came out as a shining result, especially since the differences in BMI actually turned out to be much smaller,” says Bixby. The average height of the population living there is said to be slightly lower than the average height of people living in rural areas of the same country.
This shift may indicate a narrowing gap in health care resources between the two populations. But is it because the health of people in cities is declining, or because the health of people in rural areas is catching up? It’s also hard to tell whether it’s due to , or both, said Mahesh Kala, an assistant professor of international development policy at Boston University. He is not involved in new research.
Natural migration and expanding urban development are factors that can affect people living in cities today. At the time, 55% of the world’s population lived in urban areas, according to a 2018 United Nations report. “For the first time in human history, the majority of people live in urban areas, but now the relative composition of people living in urban and rural areas is changing,” Kara says. “The composition is also changing because there is a lot of rural-to-urban migration. People are much more mobile these days. [difficult to] Disentangle these average effects. ”
Bixby says migration may underlie some of the changes, but it’s probably not the main driver of the recent trend. Past migration studies, she said, show that newcomers end up with the same health characteristics as the population they migrate to because they have access to the same services. For example, children who move to a city will have access to the same schools and services as children who have already lived there. “There is much more to be said about where migrants fall in the socio-economic distribution and whether they fully enjoy the benefits of cities, but it is more about socio-economic disparities than migration itself. ” says Bixby. “However, it is true that we do not have data that allow us to adequately quantify the role of immigrants in our study.”
Karra agrees that migration is probably not the main cause of changes in city height. “The cynical view is that if we imagine the sick moving from rural to urban areas, they [provide] Better care,” he explains. This could, in theory, reduce urban health levels and reduce population gaps. “But that’s where urban areas are declining in terms of their progress,” Kara adds. and height have increased over time, but it has increased more rapidly in rural than in urban areas, and it is likely that it will converge, either improving health or making better choices for those who remain rural. are beginning to be seen.”
Bixby adds that the countries most evident in improvements in rural heights may have experienced investments in economic growth and improved living standards. While overall height growth in both rural and urban areas is a positive trend, she stresses that inequality persists, especially in countries in sub-Saharan Africa, South Asia, the Pacific and the Middle East. Boys living in rural areas in these regions did not grow taller, and in some countries in these regions the average height of boys was shorter wherever they lived.
“We didn’t close the gap, we just saw convergence. And I think that’s pretty important. [distinction] Say it,” Kara says. In low-income countries, “children in rural areas may still lag slightly behind, so there is an opportunity to continue thinking about targeting vulnerable populations where resources are used more effectively. It also means we have to dig a little deeper into who the lagging kids are.”
Bixby and her colleagues are also working to better understand and focus on where the poorest live and how to help them. It hopes to guide where to implement policies and programs that support development.
“Even in wealthy countries, the inequality we see within cities can be enormous,” she says. “While this is not at all surprising, it is true that cities can offer many opportunities for good health, but these do not seem to be accessible to everyone. People who missed out on these opportunities.” are often the most disadvantaged, and I think that’s what the data shows.It’s kind of a warning sign against rising inequality within cities.”
