Metabolic-associated fatty liver disease (MAFLD) is on the rise. What to know

tExperts say metabolic-associated fatty liver disease (MAFLD) can be caused by a number of factors. sot/Getty Images

Researchers are reporting that the prevalence of metabolic-associated fatty liver disease is increasing dramatically in the United States.
Experts say genetics and obesity are key factors in developing the disease, but there are other causes.
They say a healthy diet and exercise can help reduce the risk of developing the disease.

Metabolic-associated fatty liver disease (MAFLD), previously known as nonalcoholic fatty liver disease, is the leading global cause of liver disease and is increasing significantly in the United States.

That’s according to a study presented today at ENDO 2023, the Endocrine Society’s annual meeting.

In their findings, which haven’t been published yet in a peer-reviewed journal, researchers analyzed data for 32,726 National Health and Nutrition Examination Survey participants.

They collected the health information from 1988 to 2018.

The scientists compared increases in MAFLD to increases in obesity. They reported that:

MAFLD increased from 16% of participants in 1988 to 37% in 2018, which is a 131% increase.
The rate of obesity rose from 23% in 1988 to 40% in 2018, which is a 74% increase.

Risk factors for MAFLD

Previously, medical professionals thought obesity was the most significant risk factor for MAFLD.

The researchers noted that because MAFLD increased more rapidly than obesity, there must be additional risk factors, such as diabetes and hypertension.

During the study period, the incidence rate for the three population groups observed increased significantly:

133% for whites
61% for Mexican Americans
56% for Blacks

Compared to the overall population, Mexican Americans had the higher prevalence of MAFLD at all times during the study.

“For years, it has been noted that Hispanics/Latinos have a higher prevalence of MAFLD,” said Dr. Aymin Delgado-Borrego, a hepatologist with KIDZ Medical who was not involved in the study.

“This is not generalizable to all Hispanics, as Mexicans and Central Americans have a higher prevalence than Latinos from other countries,” she told Medical News Today.

“However, an important finding of the study is that although Hispanics are more commonly affected, the increase in prevalence was more profound among non-Hispanic whites. Once again, this is an important fact that can be used to better understand the multiple factors that account for MAFLD.”

— Dr. Aymin Delgado-Borrego, hepatologist

What to know about metabolic-associated fatty liver disease

The term metabolic-associated fatty liver disease encompasses a spectrum of liver diseases not directly caused by alcohol consumption, according to a 2020 report published in the World Journal of Hepatology.

MAFLD is one of the top reasons for liver transplants. It is also now the leading global cause of liver disease.

“In 2015 and earlier, [viral] hepatitis was the most common cause of liver disease,” said Dr. Hillel Tobias, a specialist in transplant hepatology, gastroenterology, and internal medicine at Northwell Lenox Hill Hospital in New York who was not involved in the study.

“Once we discovered drugs that could cure [viral] hepatitis, MAFLD became the number one cause,” he told MNT.

Symptoms and causes of MALFD

MALFD has few or no symptoms, making it a silent disease, according to the National Institutes of Health. People with symptoms can have fatigue or discomfort in the upper right side of the abdomen.

One cause of MAFLD is genes. It is considered genetic in Mexican Americans, so people in that ethnic group are more likely to develop the disease.

Other causes include:

overweight or obesity
insulin resistance or type 2 diabetes
Abnormal levels of fats in your blood, such as high levels of triglycerides, high cholesterol, and low HDL
metabolic syndrome, which includes large waist size, high levels of triglycerides, low HDL, high blood pressure, high blood glucose, or type 2 diabetes

Scientists are currently studying a possible link between diets high in fructose and MALFD. They are also looking at whether gut microbiome could affect it.

Environment, diet may play a role in MAFLD

Researchers have linked several toxins in the environment to fatty liver disease, according to the National Institutes of Health (NIH).

Chemicals such as vinyl chloride, used in manufacturing PVC, and others common in households can contribute to it.

“Some people are predisposed to MAFLD, shown by the high incidence rate in Hispanics,” Dr. Hillel said.

“Some of this can be attributed to the big diet change between Mexico and the United States. The U.S. diet includes many more carbohydrates and the high rate could have something to do with going from one eating pattern to another. You can get fatty liver by eating a diet high in carbohydrates.”

“COVID-19 could also have contributed to the higher rates because when everyone was confined to their homes, their diets changed.” Dr. Hillel added. “Many people started eating better, but many relied on processed and fast foods, which are very high in carbohydrates.”

“Overall, although I somewhat agree with the outcomes, this was not really a good study,” Dr. Hillel continued. “We need to see the results replicated and back up these results with other studies.”

Reducing the risk of fatty liver disease

If found early, it is possible to reverse MALFD because the liver can repair itself, experts say.

However, because it is a silent (or at least very quiet) disease, it is not often detected early.

Blood tests and imaging tests can point to the condition. A biopsy is the only way to tell if the disease has progressed to a dangerous stage.

“If it is not addressed, it can develop into cirrhosis,” Dr. Lisa Ganjhu, a gastroenterologist and hepatologist at NYU Langone Health in New York who was not involved in the study, told Medical News Today.

But there are ways to reduce your risk of developing the disease.

“Folks can make lifestyle changes that have big returns on their investment,” said Caroline Thomason, a Virginia-based dietitian who was not involved in the study.

“In general, MAFLD results from not enough activity and eating too many calories over time. Once our bodies start accumulating fat, it gets stored in our liver. Focus on making sustainable changes to your diet to reduce calories — particularly from excess fats and sugars. Limit sugar-sweetened beverages, fried foods, refined flours, and foods with added sugars. Focus on increasing your fresh fruits and veggies, swap refined grains for whole grains, incorporate lean proteins like chicken, fish, and turkey, and emphasize heart-healthy fats like olive oil, avocado, and nuts.”

— Caroline Thomason, dietitian

Fatty liver disease can be reversed, notes Ganjhu.

“Our livers can regenerate and heal themselves. But only if the insulting factor is removed. For example, if obesity is the cause, the liver will not repair itself if someone remains obese. But if they lose weight, exercise, and live a healthy life, the liver can regenerate,” Ganjhu said.

The most important way to prevent MAFLD is to better understand it, experts say.

“It is crucial to spread awareness of the importance of this condition and its associated comorbidities,” Dr. Delgado-Borrego said.

“Educating the public about the importance of healthy diet and exercise remains the main method of prevention and management of this condition, but it is not enough. Important barriers prevent the population at large from having access to optimal nutrition and engaging in adequate physical activity, and such barriers need to be addressed at the local, national and global level to prevent MAFLD. Ultimately, funds need to be devoted for research in all aspects of this condition, focusing on prevention as well as on treatment.”