Fatty liver disease is a group of disorders that occur when too much fat builds up in the liver. Many people may have heard of alcohol-related fatty liver disease, a condition in which moderate to heavy consumption of alcohol leads to fat buildup and scarring in the liver. However, non-alcoholic fatty liver disease (NAFLD) can also threaten your health, even if you do not drink alcohol regularly. Common ingredients in the food we eat may be involved in the development of the disease.

Each day, the average person living in the U.S. consumes close to 55 grams of fructose—a kind of sugar found in fruits and vegetables and added to certain foods. Teens eat even more of this type of sugar from juices and soda. For many years, some researchers believed that fructose or high-fructose corn syrupwas linked to NAFLD development. However, not everyone agreed. Others thought that our bodies digested and metabolized fructose better than glucose after a meal, making it a healthier option

In 2015, researchers showed a direct link between high-fructose corn syrup and NAFLD. As a result, the U.S. Food and Drug Administration suggested that people living in the U.S. reduce their fructose intake. Red meat and foods high in fat and carbohydrates are also being studied to determine their role in NAFLD.

With the rise of sugar consumption in the U.S., the rates of both type 1 and type 2 diabetes have also increased dramatically. Many people with these conditions also have fatty liver disease. The liver plays an important role in regulating blood sugar, but the fat that surrounds the organ makes it hard for the liver to do its job and increases insulin resistance. This makes the combination of diabetes and fatty liver disease very difficult to treat, underscoring the importance of finding new and effective treatments. 

Our lab continues to explore how macronutrients such as amino acids, lipids and carbohydrates can influence the onset of metabolic diseases in the liver. Until changes in food processing are made globally, we will need to continue to watch what we eat, saving soft drinks and pre-packaged foods as occasional treats.

Jaclyn Welles is a PhD student in cellular and molecular physiology at the Pennsylvania State University College of Medicine. Her thesis work in the lab of Scot Kimball, PhD, focuses on liver physiology and nutrition, mainly how nutrients in our diet can play a role in influencing mRNA translation in the liver.