Researchers in Bangladesh followed children for 7 years to see if early access to clean water, better bathrooms, handwashing, and nutrition support would help them develop better. They found that children who received these interventions showed small but real improvements in thinking skills and behavior compared to children who didn’t receive them. The benefits lasted years after the programs ended. Kids were kinder to others, had fewer behavior problems, and their moms felt less sad. While the improvements were modest, they suggest that helping families with basic health needs early in life can have long-lasting positive effects on how children grow and learn.

The Quick Take

  • What they studied: Whether giving families access to clean drinking water, improved toilets, soap for handwashing, and nutrition support during pregnancy and early childhood would help children think better and behave better when they reached school age.
  • Who participated: About 3,833 children in rural Bangladesh whose mothers were pregnant when the study started in 2012. Researchers checked on them again when the children were 7 years old, around 5 years after the programs ended.
  • Key finding: Children who received nutrition support, better sanitation, or a combination of all interventions showed small improvements in thinking skills. Many children who received any of the programs were kinder to others and had fewer behavior problems. These benefits were still visible years after the programs ended.
  • What it means for you: If you live in an area with limited access to clean water and sanitation, these basic health improvements may help your child’s brain development and behavior. However, the improvements were small, and this study was done in rural Bangladesh, so results might be different in other places. Talk to your doctor about what’s most important for your child’s health in your community.

The Research Details

This was a long-term follow-up study based on a larger experiment that started in 2012. Researchers divided pregnant women in rural Bangladesh into different groups: some got clean drinking water, some got better toilets, some got soap and handwashing education, some got nutrition counseling and special supplements, some got combinations of these, and some got nothing (the control group). The original program lasted 2 years. Five years after it ended, when the children were 7 years old, researchers tracked down the families again and tested the children’s thinking skills, behavior, motor abilities, and school performance. They also asked mothers about their mental health and how much they played with and talked to their children at home.

This research design is powerful because it follows the same children over many years, which helps show whether early interventions have lasting effects. By randomly assigning families to different groups, researchers could be more confident that any differences were caused by the programs, not by other factors. Testing children years after the programs ended shows whether benefits stick around or fade away.

This study has several strengths: it involved thousands of children across many villages, used standardized tests to measure thinking and behavior, and followed children for years. However, some families couldn’t be found for the follow-up (about 25% were lost), which could affect the results. The study was also interrupted by COVID-19, which caused a 6-month pause in data collection. The improvements found were small, which means they’re real but not dramatic.

What the Results Show

Children who received nutrition support showed small improvements in thinking skills compared to children who got nothing. Children who got better sanitation also showed small thinking improvements. When all interventions were combined with nutrition, thinking improvements were slightly larger. The effect sizes were small (ranging from 0.10 to 0.15 on a standard scale), meaning the differences were noticeable but not huge.

Behavior improvements were more consistent and slightly larger. Children in almost all intervention groups were kinder and more helpful to others, and they had fewer behavior problems like aggression or defiance. These behavior improvements were about twice as large as the thinking improvements.

Surprisingly, the programs didn’t improve fine motor skills (like writing or drawing), executive function (like planning and organizing), or school achievement test scores. This suggests the interventions helped with thinking and behavior in specific ways, but not across all areas of development.

Mothers who received handwashing education, nutrition support, or both reported feeling less depressed and sad. This is important because a mother’s mental health affects how much she can help her child learn and grow. All intervention groups showed improvements in the home environment—families had more toys, books, and activities that help children learn. These home environment improvements were among the largest effects found in the study.

The original study found that these interventions helped 1- and 2-year-old children have less diarrhea and grow taller. This follow-up study shows that some benefits continue into school age, but in different ways. Instead of preventing disease, the lasting benefits appear to be in brain development and behavior. This suggests that early interventions may have multiple ways of helping children that show up at different ages.

The biggest limitation is that about 25% of families couldn’t be found for the follow-up study, which could bias the results if the families who left were different from those who stayed. The study was done in rural Bangladesh, so results might not apply to other countries or cities. The improvements were small, so while they’re real and consistent, they’re not life-changing. The study couldn’t fully explain why these interventions helped—understanding the reasons would help design better programs in the future.

The Bottom Line

If you have young children and live in an area with limited access to clean water or sanitation, these basic improvements appear to help child development (moderate confidence). Nutrition support during pregnancy and early childhood shows promise for brain development (moderate confidence). Handwashing education may help reduce depression in mothers (moderate confidence). However, these programs work best as part of a broader approach to child health—they’re not a substitute for medical care, education, or other support.

Families in low-income areas with limited access to clean water and sanitation should care about this research. Public health officials and organizations working in developing countries should consider these findings when planning programs. Parents who want to support their child’s brain development should know that basic health needs like clean water and good nutrition matter. This research is less directly relevant to families in wealthy countries with good water systems and sanitation, though the general principle that early health matters for development applies everywhere.

The benefits found in this study took years to show up—researchers measured them when children were 7 years old, about 5 years after the programs ended. This means you shouldn’t expect immediate changes in thinking or behavior. However, some benefits like improved behavior and better home environments might appear sooner. Long-term commitment to these interventions appears necessary to see lasting effects.

Want to Apply This Research?

  • Track your child’s behavior and social skills weekly using a simple checklist: Is your child kind to siblings or friends? Does your child help when asked? Does your child have fewer angry outbursts? Rate each on a scale of 1-5. Also track your own mood and stress levels, since maternal mental health affects child development.
  • If you have access to the app, set reminders for daily handwashing with soap at key times (before eating, after bathroom, before preparing food). Log when you spend 15-30 minutes playing, talking, or reading with your child. Track access to clean drinking water and note any improvements in your child’s health. If you’re pregnant or planning pregnancy, log nutrition intake and any supplements you’re taking.
  • Over 3-6 months, track whether your child’s behavior becomes more cooperative and kind. Monitor your own mental health and stress levels monthly. Every 6 months, assess your home environment: Do you have more books, toys, or learning materials? Is there more time for family activities? These long-term changes are more important than week-to-week variations.

This research describes a study conducted in rural Bangladesh and may not apply to all populations or settings. The improvements found were small and should not be considered a substitute for medical care, professional mental health support, or educational services. If you have concerns about your child’s development, behavior, or learning, consult with a pediatrician or child development specialist. Pregnant women should work with their healthcare provider to ensure adequate nutrition and prenatal care. This summary is for educational purposes and does not constitute medical advice.