Metabolic Dysfunction-associated Steatotic Liver Disease and How to Prevent It

Metabolic dysfunction-associated steatotic liver disease (MASLD, formerly known as nonalcoholic fatty liver disease or NAFLD), is on the rise in the United States thanks to a huge increase in obesity rates over the last three decades. In industrialized countries, 20-40% of the general population has some form of fatty liver (or steatotic) disease and the chances of its progressing increase with age.

Officially recognized as a disease in the early 1980s, MASLD perplexed the medical community. Obese and diabetic patients had elevated liver enzymes and enlarged livers virtually identical to those typically seen in alcoholics, but most of them insisted they were not drinking excessively.

Liver Function Basics

The liver is your largest internal organ. It performs hundreds of functions including:

• Processing everything you eat and drink
• Pulling toxins from your blood
• Fighting off infection
• Controlling blood sugar levels
• Helping to manufacture hormones and proteins

Symptoms

The liver normally weighs about three pounds. When more than 5-10% of your liver’s weight is fat, you have a “fatty liver.” While excess liver fat, or steatosis, causes no problems for some, it can cause symptoms of impaired liver function, including:

• Fatigue
• Nausea
• Abdominal pain
• Yellowing skin or eyes (as in jaundice)

Inflammation that causes scarring is a hallmark symptom of liver injury in advanced MASLD, which can lead to cirrhosis. Once you damage your liver, your body lays down collagen to repair it. Fibrosis or thickening of the liver tissue then ensues.

As MASLD progresses, about 10% of cases will develop over the next ten years into the much more serious metabolic dysfunction-associated steatohepatitis (MASH, formerly known as nonalcoholic steatohepatitis or NASH). MASH can lead to:

• Cirrhosis or hardening of the liver
• Liver failure
• Liver cancer
• Death

Diagnosis

An accurate diagnosis of MASLD is the first step towards treating this, sometimes, serious health condition. Your physician will usually diagnose fatty liver disease by:

• Administering tests to detect elevated liver enzymes
• Ordering an ultrasound to determine if you have an enlarged liver
• Performing a  liver biopsy to determine whether you have MASH or simple fatty liver

Risk Factors

Though the exact causes of MASLD are not known, patients have some pre-existing conditions in common, including:

• Type 2 diabetes
• Obesity (particularly when fat is concentrated in the abdomen)
• Have metabolic syndrome diagnosis
• Sleep apnea
• Underactive thyroid (hypothyroidism)

What’s more, the severity of MASLD increases with the degree of obesity, and abdominal or belly fat seems to increase the risk of dangerous MASH, even in patients with a body mass index (BMI) in the normal range.

Dietary Considerations

What you eat and the nutrition it provides contributes to the onset, progression, and treatment of MASLD. You may be able to prevent MASLD by eating a healthy diet and maintaining a healthy weight. Dietary factors that increase your risk include consuming:

• A high-calorie diet
• A diet rich in hydrogenated oil (trans fats)
• Too much protein from animal sources, resulting in a high intake of saturated fat and cholesterol
• Too many beverages sweetened with high fructose corn syrup

Dietary factors that reduce your risk of MASLD include:

• Consuming fewer calories
• Eating protein from whey or vegetable sources, instead of from meat and cheese
• Losing 3 to 10 percent of your bodyweight (weight loss can reduce fat, inflammation, and fibrosis in the liver)
• Adding fiber, green tea, and coffee to your diet