Research shows that inadequate protein during pregnancy and nursing causes harmful changes in lung structure and function in both mothers and babies. A 2026 study found that pregnant rats fed a low-protein diet (6% versus normal 17%) developed extra scar tissue in their lungs and reduced lung flexibility, while their female offspring showed smaller air sacs, abnormal gene expression, and impaired energy metabolism in lung tissue. According to Gram Research analysis, these findings suggest that maternal protein restriction adversely affects pulmonary health across generations, potentially increasing lifelong respiratory disease risk.
A new study shows that when pregnant rats don’t get enough protein, it harms the lungs of both the mother and her babies. Researchers found that low protein during pregnancy and nursing caused structural changes in the lungs—like extra scar tissue and fewer tiny air sacs—that could affect breathing throughout life. According to Gram Research analysis, these findings support the idea that what mothers eat during pregnancy has lasting effects on children’s health, even into adulthood. The study suggests that proper nutrition during pregnancy and nursing is crucial for developing healthy lungs in both mothers and their offspring.
Key Statistics
A 2026 research article examining pregnant and nursing rats found that maternal protein restriction increased collagen deposition and mast cell density in maternal lungs while reducing reticular fibers, indicating structural lung remodeling that could compromise ventilatory function.
In female offspring exposed to maternal protein restriction, the 2026 study documented reduced alveolar diameter, increased collagen deposition, elevated MMP-2 activity, and decreased mTOR expression, indicating delayed pulmonary development and extracellular matrix remodeling.
The 2026 research demonstrated that maternal protein restriction altered PI3K and MyoD expression while decreasing Nduf transcript levels in female offspring lungs, suggesting disturbances in smooth muscle-related pathways and energy metabolism.
According to the 2026 study, maternal protein restriction promoted structural remodeling in both dams and female offspring lungs, with no significant alterations in antioxidant parameters observed in either generation, indicating selective targeting of lung development pathways.
The Quick Take
- What they studied: How eating too little protein during pregnancy and nursing affects lung development and health in mothers and their babies
- Who participated: Female rats that were fed either normal protein (17%) or very low protein (6%) diets throughout pregnancy and nursing, plus their female offspring
- Key finding: Mothers and babies exposed to low protein developed unhealthy lung changes including extra scar tissue, fewer air sacs, and changes in how their lungs process energy
- What it means for you: This research suggests that adequate protein intake during pregnancy and nursing is important for healthy lung development in both mothers and children. While this was animal research, it highlights why prenatal nutrition matters for lifelong respiratory health
The Research Details
Researchers used laboratory rats to study how protein restriction during pregnancy affects lung health. They divided pregnant rats into two groups: one eating a normal diet with 17% protein and another eating a low-protein diet with only 6% protein. Both groups continued their assigned diets through pregnancy and nursing. When the babies were weaned (around 3 weeks old), researchers examined the lungs of both the mothers and their female offspring using multiple techniques including microscopy, chemical analysis, and genetic testing.
This approach allowed scientists to see exactly what changes happened in lung tissue and which genes and proteins were affected. They looked at things like how much scar tissue formed, the size of air sacs, and how well the lungs could process energy and fight damage.
This research design is important because it shows cause-and-effect relationships that would be impossible to study directly in humans. By controlling exactly what the rats ate, researchers could isolate the effects of protein restriction from other factors. The study also examined both mothers and offspring, which is crucial because previous research mostly focused on babies, missing important information about how maternal nutrition affects the mother’s own health.
This study used established animal models and multiple scientific techniques to measure lung changes, making the findings more reliable. The researchers examined tissue samples under microscopes, measured chemical markers, and analyzed gene expression patterns. However, because this was animal research, results may not directly apply to humans. The study was published in a peer-reviewed scientific journal, meaning other experts reviewed the work before publication.
What the Results Show
In mothers exposed to low protein, the lungs showed several harmful changes. They developed extra collagen (scar tissue), had more mast cells (immune cells that can cause inflammation), and lost some of the supporting fibers that give lungs their structure. These changes suggest the mothers’ lungs became stiffer and less flexible, which could make breathing harder.
In female babies exposed to low protein in the womb and through nursing, the damage was different but equally concerning. Their lungs had smaller air sacs (the tiny pouches where oxygen enters the blood), fewer supporting fibers, and extra scar tissue. Additionally, their lungs showed changes in genes related to muscle function and energy production, suggesting their lungs weren’t developing normally.
Both mothers and offspring showed signs that their lungs were being remodeled—essentially rebuilt in unhealthy ways. The mothers’ lungs appeared to be getting stiffer, while the babies’ lungs weren’t growing properly. These changes could affect breathing ability throughout life.
The study found that low protein affected how the babies’ lungs processed energy at the cellular level. Genes involved in muscle development and energy metabolism were altered, suggesting the lung tissue wasn’t functioning optimally. Interestingly, the researchers didn’t find major changes in the body’s natural antioxidant defenses (the system that protects against cellular damage), which was somewhat surprising. The changes in enzymes called MMPs suggest the lung tissue structure was being actively broken down and rebuilt in abnormal ways.
This research builds on the Developmental Origins of Health and Disease (DOHaD) theory, which proposes that poor nutrition during critical developmental windows can cause lifelong health problems. Previous studies showed that maternal protein restriction harms offspring lung development, but this study is novel because it also examined how the mother’s own lungs are affected. The findings align with other research showing that maternal nutrition during pregnancy has lasting effects on children’s health, but extend this knowledge to respiratory health in both generations.
This study used laboratory rats, not humans, so results may not directly apply to people. The researchers only studied female offspring, so effects on males remain unknown. The study examined lungs at one specific time point (weaning), so it’s unclear how these changes progress as the animals age. Additionally, the study didn’t measure actual breathing function, only structural and molecular changes, so the real-world impact on respiratory performance is unclear. The exact mechanisms explaining why these changes occur weren’t fully identified.
The Bottom Line
Based on this research, pregnant and nursing women should ensure adequate protein intake (typically 70+ grams daily, or about 1.1 grams per kilogram of body weight). While this animal study doesn’t prove the same effects occur in humans, it provides strong biological plausibility for why prenatal nutrition matters. Consult with a healthcare provider or registered dietitian for personalized protein recommendations during pregnancy and nursing.
Pregnant women, women planning pregnancy, and healthcare providers should pay attention to these findings. The research is particularly relevant for populations at risk of malnutrition. However, this was animal research, so while it’s informative, it shouldn’t replace medical advice from qualified healthcare professionals.
If these findings apply to humans, lung changes would begin during pregnancy and continue through early childhood. The effects appear to be long-term or permanent, potentially affecting respiratory health throughout life. Benefits of adequate protein intake would likely be seen through normal fetal development and childhood growth.
Frequently Asked Questions
How much protein do pregnant women need to support healthy fetal lung development?
Pregnant women typically need 70+ grams of protein daily, or about 1.1 grams per kilogram of body weight. This research suggests adequate protein is crucial for fetal lung development. Consult your healthcare provider or registered dietitian for personalized recommendations based on your individual needs.
Can maternal malnutrition during pregnancy cause permanent lung damage in babies?
This animal study suggests that inadequate protein during pregnancy causes structural lung changes that appear to be long-lasting. The research found reduced air sacs, extra scar tissue, and abnormal gene expression in offspring lungs. While this was animal research, it supports the importance of adequate maternal nutrition for healthy fetal development.
Does low protein during pregnancy affect the mother’s lungs too?
Yes, this 2026 study found that maternal protein restriction caused lung changes in mothers themselves, including extra scar tissue and reduced structural fibers. These changes could make lungs stiffer and potentially affect breathing ability, suggesting maternal nutrition impacts the mother’s own respiratory health.
What foods are good protein sources for pregnant women?
Excellent protein sources include lean meats, fish, eggs, dairy products, legumes (beans and lentils), nuts, and seeds. Aim for variety throughout the day. A registered dietitian can help you create a personalized nutrition plan that meets your protein needs during pregnancy and nursing.
Is this research directly applicable to human pregnancy?
This study used laboratory rats, so results may not directly apply to humans. However, it provides strong biological evidence for why maternal protein nutrition matters for fetal lung development. Always consult healthcare providers for medical advice rather than relying solely on animal research findings.
Want to Apply This Research?
- Track daily protein intake in grams, aiming for 70+ grams daily during pregnancy and nursing. Log protein sources at each meal to ensure variety and adequate intake.
- Add one high-protein food to each meal: eggs at breakfast, Greek yogurt as a snack, lean meat or legumes at lunch and dinner. Use the app to set daily protein goals and receive reminders.
- Monitor protein intake weekly and track weight gain patterns during pregnancy. Note any respiratory symptoms or concerns and discuss with healthcare provider. Continue tracking postpartum during nursing period.
This research was conducted in laboratory rats and has not been directly tested in humans. While the findings suggest important connections between maternal protein nutrition and fetal lung development, individual human responses may differ. Pregnant women should consult with their healthcare provider or registered dietitian before making dietary changes. This article is for informational purposes only and should not replace professional medical advice. If you have concerns about your nutrition during pregnancy or your child’s respiratory health, speak with a qualified healthcare professional.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.