Infant Formula Fats and Liver Health: New Research Raises Questions

Certain fats used in some infant formulas may strain the developing liver and contribute to early signs of steatotic liver disease, according to a new study led by researchers at Virginia Tech. The research highlights the importance of understanding how early nutrition impacts liver health, particularly as steatotic liver disease – formerly known as non-alcoholic fatty liver disease – is increasingly diagnosed in infants and children.

How Infant Formulas Differ in Fat Composition

Infant formulas are designed to provide complete nutrition and typically use blends of plant-based oils to mimic the fat composition of breast milk. However, the study, published in the American Journal of Physiology-Endocrinology and Metabolism, focused on the impact of different types of fats. Researchers tested two simplified formulas differing only in fat type: one rich in medium-chain fatty acids (MCFAs) derived primarily from coconut oil, and the other rich in long-chain fatty acids (LCFAs) derived from animal fat.

Study Findings: Medium-Chain Fats and Liver Fat Accumulation

Newborn pigs fed the formula with specific medium-chain fats accumulated liver fat more rapidly than those fed the formula with long-chain fats, despite receiving the same amount of calories and protein. “Even within seven days, we could see fat starting to build up in the liver,” said Associate Professor Samer El-Kadi of the School of Animal Sciences at Virginia Tech . “By about two weeks, it had progressed from simple steatosis to a more severe inflammatory form of the disease.”

A Different Mechanism Than Adult Liver Disease

The study also revealed that steatotic liver disease develops differently in early life compared to adults. In adults, fat buildup occurs when the liver slows down its fat-burning process. However, in the developing liver, researchers observed that fat accumulated even as fat burning increased. “We saw the liver activate both fat-making and fat-burning pathways at the same time,” El-Kadi explained . “Even with those adaptive responses, the developing liver became overwhelmed. That was surprising to us. Based on what we understand from adult disease, increased fat burning should have been protective.”

Steatotic Liver Disease: A Growing Concern

Steatotic liver disease, characterized by excess fat buildup in the liver, was once considered a condition primarily affecting adults with obesity. However, diagnoses are increasing among children and infants, prompting investigations into the role of early nutrition on liver health.

Essential Considerations for Parents

El-Kadi emphasizes that the study does not recommend avoiding infant formula. Breast milk remains the “gold standard” for infant nutrition, but formula is a critical and often life-saving alternative when breastfeeding isn’t possible or sufficient. “When our own child needed supplemental nutrition, we used formula—no questions asked,” El-Kadi stated . “The immediate benefits of feeding far outweigh any potential long-term risks. Our goal is not to discourage formula use. It’s to understand how different components of formula affect the developing body, so they can be improved over time.”

Future Research and Operation Stork Speed

The research team is continuing to investigate how specific fatty acids influence liver metabolism during early life, including whether different types of medium-chain fatty acids have varying effects and optimal quantities. This research aligns with the US Department of Health and Human Services and the Food and Drug Administration’s Operation Stork Speed initiative, which aims to improve infant formula safety and nutritional quality .