Researchers studied nearly 1,700 children ages 3-5 to understand how different eating patterns affect asthma risk. They found that children who ate healthier diets—following patterns like the Mediterranean diet or DASH diet—had significantly lower rates of asthma. The study suggests that eating foods that reduce inflammation in the body, like fruits, vegetables, and whole grains, may protect children from developing asthma. The connection appears to work partly through helping children maintain a healthier weight and reducing belly fat. While more research is needed, these findings suggest that what children eat could be an important way to prevent asthma.

The Quick Take

  • What they studied: Whether eating healthier foods helps prevent asthma in young children, and whether this protection works by helping kids maintain a healthy weight
  • Who participated: 1,695 children between ages 3 and 5 years old from a large national health survey conducted between 2011 and 2018
  • Key finding: Children who followed healthier eating patterns had 7-11% lower risk of asthma for each point increase in their diet quality score. The Mediterranean diet showed the strongest protection, reducing asthma risk by 11%.
  • What it means for you: Feeding young children more fruits, vegetables, whole grains, and healthy fats may help prevent asthma. This appears to work partly by keeping children at a healthier weight. However, this study shows a connection, not proof that diet causes lower asthma rates—more research is needed before making major dietary changes.

The Research Details

Researchers used information from a large national health survey called NHANES that collected data from 2011 to 2018. They looked at what children ate and compared it to five different healthy eating patterns: DASH (Dietary Approaches to Stop Hypertension), AHEI (Alternative Healthy Eating Index), HEI-2020 (Healthy Eating Index 2020), Mediterranean Diet, and DII (Dietary Inflammatory Index). They scored each child’s diet based on how well they followed these patterns.

The researchers then used statistical methods to see if children with higher diet quality scores were less likely to have asthma. They also measured children’s weight, height, and body fat to understand whether staying at a healthy weight might explain part of the connection between diet and asthma.

This type of study is called cross-sectional, meaning researchers looked at all the information at one point in time rather than following children over months or years.

Understanding how diet affects asthma is important because asthma is very common in children and affects their ability to play, exercise, and go to school. If eating healthier foods can help prevent asthma, it would give parents a practical tool to protect their children’s health. This study helps explain not just that diet matters, but how it might work—through reducing inflammation and maintaining healthy weight.

This study used data from a well-respected national survey, which is a strength. However, because it’s cross-sectional, we can’t be certain that diet causes lower asthma rates—it’s possible that children with asthma eat differently for other reasons. The study also relied on parents reporting what their children ate, which might not be perfectly accurate. The findings are consistent with previous research suggesting that anti-inflammatory diets help prevent asthma.

What the Results Show

Children who followed the Mediterranean diet most closely had the strongest protection, with an 11% lower risk of asthma compared to those who followed it less closely. Children following the DASH diet had a 7% lower asthma risk, while those following AHEI and HEI-2020 had a 2% lower risk for each point increase in their diet quality score.

The study found that all five healthy eating patterns showed some protection against asthma, though the Mediterranean diet was most effective. Interestingly, the diet that focused on reducing inflammatory foods (DII) did not show a significant protective effect in this age group, though the researchers expected it might.

The researchers also discovered that the connection between healthy eating and lower asthma risk worked partly through weight management. Children who ate healthier diets tended to have healthier weights and less belly fat, and this appeared to explain some of the asthma protection.

The study found that three different measures of body fat—regular BMI (weight for height), LAP (a measure of belly fat), and VAI (another belly fat measurement)—all helped explain why healthier diets reduced asthma risk. This suggests that maintaining a healthy weight, especially avoiding excess belly fat, is one important way that good nutrition protects against asthma. The fact that multiple body fat measures showed this effect makes the finding more reliable.

This research supports previous studies showing that anti-inflammatory diets help prevent asthma in children. The finding that weight management plays a role is also consistent with other research showing that overweight children have higher asthma rates. However, this is one of the first studies to compare five different healthy eating patterns directly in young children and to examine how weight might explain the connection.

The study looked at children at one point in time, so we can’t prove that diet causes lower asthma rates—only that they’re connected. The study relied on parents reporting what their children ate, which might not be completely accurate. The study included children ages 3-5, so results might not apply to older children or teenagers. The study couldn’t account for all possible factors that might affect asthma, such as air pollution or family history of asthma. Finally, the study was observational, meaning it can’t prove cause-and-effect the way a controlled experiment could.

The Bottom Line

Based on this research, parents of young children may consider encouraging eating patterns similar to the Mediterranean diet (lots of fruits, vegetables, whole grains, fish, and olive oil) or the DASH diet (similar foods with emphasis on low sodium). These patterns appear to have moderate evidence supporting asthma prevention. However, this should not replace medical treatment for children who already have asthma. Parents should discuss dietary changes with their child’s doctor, especially if their child has asthma or is at high risk.

This research is most relevant to parents of young children (ages 3-5) who want to prevent asthma, or parents of children with a family history of asthma. It may also interest pediatricians and nutritionists working with young children. Children who already have asthma should continue their prescribed medications and treatments—this research suggests diet might help prevent asthma, not treat it. The findings may be less relevant to older children or teenagers, as this study only included very young children.

This study shows a connection at one point in time, so we don’t know how long it takes for dietary changes to affect asthma risk. Based on other nutrition research, it typically takes several weeks to months of consistent healthy eating to see health benefits. Parents should expect this to be a long-term approach to health, not a quick fix.

Want to Apply This Research?

  • Track daily servings of fruits, vegetables, whole grains, and fish. Set a goal of 5+ servings of fruits and vegetables daily and 2-3 fish meals per week. Monitor these weekly to see if the child is moving toward a Mediterranean or DASH eating pattern.
  • Start by adding one Mediterranean or DASH-style meal per week (such as baked fish with roasted vegetables and olive oil). Gradually increase to 2-3 times per week. Use the app to log meals and track progress toward healthier eating patterns rather than focusing on restriction.
  • Track diet quality weekly using a simple scoring system based on the Mediterranean diet components (fruits, vegetables, whole grains, fish, olive oil). Also monitor the child’s weight and growth with their pediatrician to ensure healthy development. Note any changes in respiratory health or asthma symptoms over months, though dietary changes are typically a long-term prevention strategy.

This research shows a connection between healthy eating patterns and lower asthma risk in young children, but does not prove that diet causes this protection. This information is for educational purposes and should not replace medical advice from a pediatrician. Children with asthma should continue taking prescribed medications as directed by their doctor. Before making significant dietary changes for your child, especially if they have asthma or other health conditions, consult with your pediatrician or a registered dietitian. This study was conducted in children ages 3-5, so results may not apply to older children or adults.