When people think of liver disease they usually associate it with alcohol abuse or hepatitis. But there is another, much more prevalent factor at play, and it’s becoming increasingly worrisome as trends reveal the startling truth. Statistics clearly show that children and adults in the U.S. are getting heavier and this is only predicted to increase. Being overweight does not always come with risks to health, in fact, being underweight has its own set of health risks. However, being obese is associated with conditions that can lead to chronic illness and early death. In 2007/2008 33.8% of adults over 20 years old in the U.S. were estimated to be obese, and 5.7% were extremely obese. Last year, 2019 figures from the CDC found that 36.5% of U.S. adults age 20 and older and 17% of children and adolescents aged 2–19 years were obese.
Obesity is associated with the following chronic health conditions:
- Heart disease
- High blood pressure
- Gall bladder disease
- Breathing issues, such as sleep apnea
Obesity and Non-alcoholic Fatty Liver Disease
A disease associated with obesity that is sometimes overlooked is non-alcoholic fatty liver disease (NAFLD). NAFLD is the build-up of fatty tissue in the liver despite drinking little to no alcohol. It is a leading problem in overweight, obese, pre-diabetic, and diabetic adults, no matter the age or sex. It is becoming the most common liver disease in the U.S.
While NAFLD is generally considered to be benign, it can lead to a much more serious illness: non-alcoholic steatohepatitis (NASH). NASH causes inflammation in the liver, which leads to scarring, fibrosis and cirrhosis. In fact, NASH is in the group with alcoholism and hepatitis C as being an established risk factor for liver cirrhosis. NASH is defined as inflammation combined with ‘ballooning degeneration’, which is when liver cells, called hepatocytes, become swollen and break apart leading to a chronic inflammatory response.
Diagnosing Non-alcoholic Fatty Liver Disease
Generally there are no symptoms involved in the progression of NAFLD. Most people find out that they have it from a laboratory finding in a metabolic panel, which is routine yearly blood work to assess fasting glucose and liver and kidney function. Many times NAFLD is identified by a rise in liver enzymes, namely alanine aminotransferase (ALT) and aspartate aminotransferase (AST), after hepatitis and genetic liver disease are ruled out.
As NASH develops, it may present as elevated ALT in levels greater than AST. A newer test, called FIBROSpect II, shows numerous lab values indicating liver cell injury.
Imaging is the next step in diagnosis. Ultrasound imaging of the liver will not find fatty liver until the fat has accumulated to 15-30%, which is a very significant advanced amount of fat. A Computed Tomography (CT) Scan is not typically used, however Magnet Resonance Imaging (MRI) may be a good tool. The drawback is that NAFLD cannot be distinguished from NASH using MRI. The last step in diagnosis is a liver biopsy.
NASH can progress to cirrhosis and hepatocellular cancer. Of untreated or poorly treated NAFLD patients, 30% will progress to NASH.
The Risks Facing 81 Million Adults in the U.S.
The statistics regarding the growth of NAFLD and NASH are frightening. Of all cases of liver disease, 25% are due to NAFLD. It is estimated that 25-35% of the US population has NAFLD. This is understandable given that there are 24 million diabetics and 57 million pre-diabetic people in the US; that’s 81 million people who are generally overweight or obese, just under a third of the US population. More than 90% of NAFLD patients are associated with aspects of the metabolic syndrome profile and have at least one positive index such as obesity, elevated fasting glucose, elevated triglycerides, elevated LDL, or hypertension. In fact, one-third of NAFLD patients have at least three of those features.
Looking at the statistics from another angle, 70-80% of obese patients have NAFLD, and 100% of morbidly obese patients have it (defined by having a BMI greater than or equal to 40). Approximately 70% of type 2 diabetic patients have NAFLD and 5-20% of type 2 diabetics will develop NASH-based cirrhosis as a result. NASH is equal in men and women and is now being seen in the overweight and obese pediatric population.
Risk Factors for NASH:
- Obesity and insulin resistance
- Consuming alcohol at or greater than 10 drinks/week
- Acute fulminant or chronic hepatitis
- Taking drugs such as: valproic acid, corticosteroids, tamoxifen, estrogens, or methotrexate
- Environmental exposures to: organic solvents, polychlorinated biphenyls (PCBs), petrochemicals, or methylformamide
- Metabolic Abnormalities: galactosemia, glycogen storage disease, or homocystinuria
- Nutritional Status: Overnutrition, starvation diet and rapid weight loss, total parenteral nutrition (TPN), protein energy malnutrition (PEM), or Celiac Disease
Can Non-alcoholic Fatty Liver Disease be Reversed?
Standard medical care has not been established for NAFLD. In fact, some people are told that they have it but there is nothing that can done about it. However, I have seen it reversed in patients and family members. Following are potential methods for reversing NAFLD.
Weight loss when obesity is a factor has been shown to reverse NAFLD in research using animals. However, the weight loss should be gradual. Starvation diets, or diets that involve quick weight loss, can damage the liver. Losing more than 3.5 lbs./week can actually further fatty liver disease and worsen the damage to liver cells. A 1-2 lbs./week weight loss is safe and effective.
Overall, if you are obese and diagnosed with NAFLD, reducing your weight by 7% to 10% using diet and/or regular physical activity is associated with a decrease in liver fat, inflammation and fibrosis.
The best diet is one that includes healthy oils in your diet such as olive oil and avocado oil. Protein should be lean animal protein or vegetarian sources such as tofu, nuts, seeds, and beans. Grains need to be used at a minimum and should only include complex carbohydrates such as brown rice, quinoa, oats, etc. Sugar, high salt, processed food, as well as trans-fatty acids should be eliminated along with alcohol, coffee, and sugary or artificially sweetened drinks. The Mediterranean diet has been studied for reversal of NAFLD and preliminary assessment shows positive results.
A study published in February 2020, showed the beneficial effect of regular exercise on liver tissue. Exercise also improves the sensitivity against insulin, increases lipogenesis and carbohydrate metabolism, and at the same time decreases steatosis and fibrosis. Moreover, as a result of regular exercise the visceral fat tissue also decreases, which plays an important role in the inflammatory process and fibrogenesis of the liver. The alteration of the gut bacteria composition might also contribute to the positive changes in the liver.
Additionally, getting good sleep, at least 6-9 hours per night is necessary to balance hormones such as leptin and ghrelin, which are associated with appetite control.
Nutrients shown in studies to help reduce liver fat and improve insulin resistance include:
- Fish oils
- Minerals: chromium, zinc, and selenium
- Extra fiber
- Gymnema sylvestre (an herb known for its blood sugar regulation support)
- Vitamin D (if you have a deficiency)
- Alpha lipoic acid
- N-acetylcysteine (NAC)
- Vitamin E
- Certain probiotics
- Green tea
- Milk thistle
- Cordyceps sinensis
If you suspect that you are at risk for NAFLD it is important to see your primary care provider for a full laboratory work up and physical exam. I have seen cases of NAFLD that were reversed using slow weight loss, exercise and a well-researched approach to the use of nutritional supplements.