Breast-feeding children rather than using milk substitutes would add more than US$300 billion a year to the global economy, releasing money to deal with issues such as hunger, education and the environment, according to a study.
The effects on children's long-term health and cognition are so great that the authors of the study, published in The Lancet last month (30 January), say that improving breast-feeding rates would help achieve a number of the UN's Sustainable Development Goals.
The short-term benefits of breast-feeding are well-known, with another new Lancet study saying it could save the lives of 823,000 under-fives worldwide every year, as it protects babies against infections, among other benefits.
But these impacts are "dwarfed" by life-long cognitive improvements, says Nigel Rollins, a scientist at the Department of Maternal, Newborn, Child and Adolescent Health at the World Health Organization and lead author of the first study.
They found that current feeding practices during infancy wipe 0.49 per cent off the value of the global economy, or US$302 billion in 2012, compared with all children breast-feeding for at least six months.
"It's absolutely affordable for even the poorest countries to invest in [promoting] breast-feeding," Rollins says. "You can't argue with what it translates into in terms of major economic benefits."
Some developing regions are among the hardest hit, with North Africa and the Middle East losing 0.97 per cent of gross national income.
But developing countries, which see a 0.39 per cent fall, are less affected overall than developed nations, with a 0.53 per cent fall, largely because poorer countries have higher breast-feeding rates and lower salaries.
In case studies from Bangladesh, Brazil and Nigeria, Rollins' paper highlights several activities to promote breast-feeding, such as training health workers, using media publicity and strengthening maternity leave policies. All these help increase the number of breast-feeding mothers, the authors say.
These interventions are possible even in the poorest countries, but foreign donors may be needed to help cover costs, says Alison McFadden, a researcher in mother and child health at the University of Dundee in the United Kingdom, who has collected breast-feeding case studies in several developing countries.
However, global recognition of breast-feeding's significance remains too weak, McFadden says, adding that strong political leadership would help cement its importance within the global development agenda.
 Nigel Rollins and others Why invest, and what it will take to improve breastfeeding practices? (The Lancet, 30 January 2016)
 Cesar G. Victora and others Breastfeeding in the 21st century: epidemiology, mechanisms, and lifelong effect (The Lancet, 30 January 2016)
 Zulfiqar A. Bhutta and others Evidence-based interventions for improvement of maternal and child nutrition: what can be done and at what cost? (The Lancet, 3 August 2013)
 Radha Holla-Bhar and others Investing in breastfeeding - the world breastfeeding costing initiative (International Breastfeeding Journal, 23 February 2015)