Fatty Liver Disease, Metabolic Health and Air Pollution 

When you think about fatty liver, you probably think about alcohol abuse.

However, a large portion of fatty liver disease is not related to alcohol consumption, but instead, metabolic imbalances caused by diet, lifestyle and the modern environment. 

To highlight the metabolic connection, what was once known as nonalcoholic fatty liver disease, or NAFLD, is now called metabolic-associated fatty liver disease, or MAFLD. 

Given that connection, it’s not surprising that rates of fatty liver disease have been rising since the 1980s. And rising fast!

It’s currently estimated that about 25 percent of the global population has fatty liver disease. In Asia, rates increased by 40 percent in just five years from 2012 to 2017. Let those numbers sink in.

MAFLD is a legitimate  epidemic, placing a large burden on individuals, the health care system and the global economy. 

This article will cover more about MAFLD and its causes and risk factors, including air pollution, microbiome health and insulin resistance.

Keep reading to learn more about: 

  • What is MAFLD?
  • The metabolic connection, new diagnostic criteria and risk factors
  • MAFLD and toxin exposure, including new research on air pollution
  • Simple steps for MAFLD support and even reversal

What Is MAFLD?

Metabolic-associated fatty liver disease, MAFLD for short, is characterized by liver steatosis, or the accumulation of fat (triglycerides and other lipids) in the liver affecting at least five percent of hepatocytes (liver cells).

Unlike alcoholic fatty liver disease, MAFLD isn’t primarily caused by alcohol consumption, although alcohol use can contribute.

Think about MAFLD as if fat cells replaced liver cells. This decreases liver function and increases inflammation.

If the root causes aren’t treated or removed, MAFLD can progress to liver disease, liver cancer, the need for a liver transplant or even death. In its early stages, however, fatty liver is reversible. 

Fatty Liver as A Metabolic Disease

MAFLD is considered the manifestation of metabolic disorders in the liver.

Its rise tracks with changes in lifestyle and diet that occur with modernization and industrialization, which may account for the rise we are currently seeing in Asia as more western habits have been adopted in recent years.  

The liver has hundreds of functions including many metabolic transformations. It’s where the body turns glucose into triglycerides and where cholesterol and lipoproteins (LDL and HDL) are manufactured. 

Risk factors for MAFLD include: 

  • Diet high in sugar and processed foods
  • Sedentary lifestyle
  • Genetics
  • Male
  • Central/abdominal obesity
  • Dyslipidemia – high total cholesterol, high LDL cholesterol (especially small dense LDL), high triglycerides and/or low HDL cholesterol
  • Insulin resistance and associated diagnoses including metabolic syndrome, pre-diabetes and Type-2 diabetes
  • Exposure to toxins including air pollution, pesticides, endocrine disruptors and more 
  • Use of medications that strain the liver, such as Tylenol
  • Certain infections, including viruses such as Covid-19, H. Pylori, hepatitis C and HIV

Data suggests that Covid infection exhibited disturbances in liver function.

In addition, those with MAFLD are more prone to develop more severe Covid and   post-Covid syndrome.  

There is  a connection with the microbiome, or more specifically the part of the microbiome connected to metabolic health called the microbial metabolome.

Many of the risk factors for MAFLD including obesity, insulin resistance and elevated lipids, correlate with gut dysbiosis or an imbalance in the microbiome. Gut imbalances and GI pathogens are possible root causes of inflammation that influence chronic disease. 

While each individual with MAFLD likely has several root causes or triggers, people with the disease also show features of insulin resistance and metabolic syndrome. 

New diagnostic criteria for MAFLD now includes hepatic steatosis along with one or more of the following:

  • Overweight or obesity
  • Type 2 diabetes
  • Metabolic dysregulation 

The relationship between metabolic health and lifestyle is clear and this diagnosis reflects the connection between body systems that we often discuss in Functional Medicine. 

If there is MAFLD, there is also metabolic dysfunction.

We can see it clearly in the statistics:

  • MAFLD effects 43-60% of people with diabetes,
  • About 90% of those with hyperlipidemia (high cholesterol, LDL or triglycerides)
  • And 91% whose weight falls into the “morbidly obese” category.

With numbers as staggering as these, there must be more to the story.  

MAFLD And Toxins 

Detoxification is an important function of the liver where toxic compounds are transformed to be excreted from the body.

Toxin exposure puts pressure and stress on the liver to detoxify, and the pressure increases with an increased toxic burden. 

Air pollution is one type of toxin exposure with a clear connection. Air pollution is linked to millions of deaths every year. 

Like exposure to a poor diet, air pollution is also caused by industrialization.

Air pollution is already linked to a variety of metabolic diseases including insulin resistance, metabolic syndrome and Type 2 diabetes, so it isn’t a surprise that MAFLD is also connected. 

Animal studies suggest that air pollutants increase the risk of fatty liver by inducing a change in liver metabolism.

Particulate matter is especially harmful. In addition, co-exposures of air pollution with other toxins like phthalates and heavy metals found in particulates increases risk.

A recent large epidemiological study of over 90,000 Chinese adults was recently published in the Journal of Hepatology, making a connection between air pollution and fatty liver in humans. 

In the study, small particulate matter (PM1, PM2.5 and PM10) and nitrogen dioxide levels were compared to a variety of diet and lifestyle habits, health history, anthropometric measurements, lab testing and imaging. 

Scientists concluded that long-term exposure to air pollution increased risk for MAFLD, especially in men who smoke, drink, carry more weight around their midsection and eat a more Western diet. 

Toxin exposure plus a poor lifestyle equals an increased risk to the liver.

How To Prevent and Reverse MAFLD

Liver health is not disconnected from the rest of the body, by addressing root causes, it is possible to prevent and even reverse the inflammation and fatty deposits in the liver before the disease progresses and scar tissue forms. 

From a Functional Medicine perspective, here are lifestyle pieces to consider: 

1. Address insulin resistance. We often think fatty liver is driven by fat, but it’s driven by sugar, excess carbs and processed foods that increase blood sugar and insulin over time. The main changes to make here are with diet.

Ditch the processed food and limit or eliminate added sugar (including high fructose sweeteners) from the diet. Eat quality meat, fish, colorful produce and healthy fats most of the time. 

Our ancestors who ate a Paleo diet didn’t have fatty liver disease, so returning to whole, seasonal and wild foods is where to begin.

Exercise, quality sleep, stress management and addressing microbiome imbalances are important here as well. 

2. Decrease your toxic burden. Take the pressure off the liver by reducing the toxins that it must process. This includes alcohol, household toxins, water pollution and, of course, air pollution. 

Air pollution is a modifiable risk factor in chronic disease that starts with awareness. Monitor the air quality where you live and adjust outdoor activities as required, advocate for cleaner air standards and mitigate indoor air quality with air filters

3. Get tested. Risk for MAFLD can be assessed with regular lab work you might already be getting. Tests to ask for include liver enzymes (AST, GGT, and ALT), fasting blood glucose, hemoglobin A1C fasting insulin and a lipid panel.

You can self-order these tests here. Please work with your doctor for interpretation and guidance. 

4. Give your liver some extra love! The liver has a lot of jobs to do and can easily get overwhelmed. Simple measures to support liver detoxification go a long way. Some key supplements provide additional support. These include glutathione, NAC, milk thistle, curcumin, alpha lipoic acid, methylation support and others.

Hopefully, this article will shed some light on the factors that contribute to MAFLD, including our modern lifestyle and environment.

The silver lining is that many of the factors that work together to create fatty liver are within our control.

It may not be easy to build new habits, stay inside when outdoor air is poor and rework the diet but given the way human health is trending it may be essential if you desire to age without chronic disease. 


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