Nonalcoholic fatty liver disease, a condition often associated with obesity, affects an estimated 80 million people in the United States and is the most common chronic liver condition in children and adolescents. We spoke with pediatric gastroenterologist Jennifer Woo Baidal, MD, MPH, about reasons for this trend, potential health consequences, and ways to prevent or reverse the condition in children.
What is fatty liver disease and what do parents need to know about it?
Fatty liver disease occurs when too much fat accumulates in the liver and triggers an inflammatory process that injures liver cells. It’s generally symptomless, but as it progresses, fatty liver disease can interfere with critical liver functions.
With the rise in childhood obesity, more kids are developing the disease, and we’re seeing more in our practice. Many parents are aware that obesity can lead to type 2 diabetes and other serious metabolic conditions, but there is far less awareness of the link between obesity and liver disease.
There are also some genetic mutations that can increase the risk with or without obesity.
How many kids have fatty liver disease, and what is the health impact?
We diagnose it by measuring blood levels of an enzyme called ALT, which is a marker for liver damage. But it’s difficult to diagnose the inflammatory component without a liver biopsy, so prevalence estimates are inaccurate. Autopsy studies suggest that about 1 in 10 children and adolescents have fatty liver, with or without inflammation.
In adults, the disease is a growing reason for liver transplant and, in some instances, liver cancer.
We need to act early in a child’s life to prevent excess weight gain and subsequent liver inflammation.
Cirrhosis—scarring of the liver due to chronic inflammation—is rare in kids, but it’s a concerning long-term consequence that can lead to end-stage liver disease. I’ve seen a child as young as 6 with inflammation and a teen with cirrhosis.
The liver makes innumerable proteins, maintains the body’s metabolism, and filters out toxins from our blood. If it stops working, a liver transplant is the only treatment.
At what age does fatty liver disease become an issue?
Previous studies have focused on fatty liver in adolescents and young adults, so we recently looked at younger kids. We found that 3-year-olds with increased waist circumference had higher levels of ALT—a marker for liver damage—by the time they were 8. Those with greater increases in waist circumference and other measures of obesity also had higher ALT levels in mid-childhood. This shows that we need to act early in a child’s life to prevent excess weight gain and subsequent liver inflammation.
Besides losing weight, can anything else prevent or reverse nonalcoholic fatty liver disease?
Maintaining a healthy weight by eating fewer processed foods and exercising regularly is the main way for kids and adults to prevent nonalcoholic fatty liver disease.
There may also be a role for vitamin E. We’ve been studying a type of vitamin E, D-alpha tocopherol, that is used to reduce liver inflammation and injury in children and adults with fatty liver disease.
We’d like to know if vitamin E can also prevent inflammation in kids who are at risk for fatty liver disease.
Recently, we found a correlation between alpha tocopherol and ALT in young children of all weight categories: Those with lower dietary intake of alpha tocopherol—the good kind of vitamin E—had higher ALT levels in mid-childhood. This suggests that eating recommended amounts of vitamin E—an antioxidant—may prevent liver inflammation. Foods that are rich in vitamin E include spinach, tomatoes, avocados, some types of fish, and nuts and seeds.
Vitamin E from supplements is absorbed differently than the dietary kind, so it’s unclear if supplements could prevent liver inflammation. That’s a study we want to start, but we first need a noninvasive marker that is more specific than ALT and less invasive than liver biopsy to identify at-risk kids.
Should children be screened for fatty liver disease?
Screening efforts are mixed, in part because there is no treatment other than weight loss and we don’t have a perfect noninvasive screening tool. Some clinicians measure ALT levels in all obese children starting at around age 10. But as our study shows, we urgently need better ways to screen, diagnose, and treat fatty liver starting in childhood.
Dr. Woo Baidal is an assistant professor of pediatrics at Columbia University Vagelos College of Physicians and Surgeons, director of pediatric weight management in the Division of Pediatric Gastroenterology, Hepatology, and Nutrition at Columbia University Irving Medical Center, and a pediatric gastroenterologist in the Center for Adolescent Bariatric Surgery at NewYork-Presbyterian Morgan Stanley Children’s Hospital.
Read the press release about her latest study, published in The Journal of Pediatrics.