200 million under-fives are 'intellectually stunted'
点击量： 时间：2019-03-02 08:17:04
By Roxanne Khamsi At least 200 million children under the age of five currently fail to reach their full intellectual potential, a new study of developing countries estimates. Researchers blame the problem on malnutrition and inadequate cognitive and social stimulation. They also stress that many of these children could achieve their full potential with the help of relatively simple, low-cost programmes. In the first part of their analysis, Sally Grantham-McGregor of University College London, UK, and colleagues reviewed previous studies linking stunted growth and poverty to poor cognitive development during children’s early years, when critical development occurs. Grantham-McGregor says there are normal milestones for number and language comprehension that children typically reach within their first few years of life, when critical brain development occurs. One earlier Jamaican study had found, for example, that physically stunted children were more likely to drop out of school before grade 11 than their counterparts who had grown to normal height thanks to adequate nutrition. Another study conducted in Ecuador revealed that poor toddlers had weaker language skills than their wealthier counterparts. Grantham-McGregor’s team obtained recent information about poverty and height statistics from UNICEF and the World Health Organization, respectively. Of the 156 countries analysed in the new study, 126 have a known prevalence of stunting and 88 have a known proportion living in absolute poverty. The team extrapolated this data to find the number of children under age five who would have failed to achieve normal cognitive development. Of the 559 million children under five years in developing countries, they estimate that 219 million fall into this category – more than the entire child population of North America and Europe put together. Grantham-McGregor believes that the final number put forth by the study is a conservative estimate. “I think it’s a startling figure. Hopefully it will startle people to act on this issue,” says infant psychopathologist Neil Boris of Tulane University in New Orleans, Louisiana, US. Researchers say that malnutrition, such as iodine and iron deficiency, is one of the main reasons children fail to achieve their learning potential. Another problem is that their parents fail to engage them in activities that stimulate positive brain development. “You would worry most about children that have a double whammy” of both poor nutrition and inadequate intellectual stimulation, says Boris. Experts stress that both issues require simultaneous attention. “I think it’s misguided to focus on only one of those problems,” says Grantham-McGregor. “It’s critical to improve the environment of these kids so they don’t suffer deficits in cognitive development,” she adds. Interventions studied by other researcher teams have shown promise. One report found that Jamaican children scored higher on intelligence tests when their parents received simple training on how to play constructive games with them using home-made toys. “The parents don’t realise that their input can make a difference,” Grantham-McGregor says. “They really need demonstrations” showing how to engage their children. The new study estimates that these disadvantaged children end up earning at least 20% less than their peers who had a healthier start to life. Providing these children with a more nurturing environment early in life could help prevent the cycle of poverty, say researchers. Boris notes that poor cognitive development among youngsters is not just a problem of the developing world. He says that in the US alone almost 200,000 children under the age of six are placed in foster care due to neglect, which can disrupt intellectual growth. Experts say that helping children around the world at an early stage will enable the youngsters to take full advantage of educational opportunities. “Investing in programmes in children under the age of five will be both more effective and far cheaper than leaving it till later,” says Grantham-McGregor. Journal reference: The Lancet (vol 369,