Fatty liver disease impacts between 80 to 100 million people in the US, and it's on the rise!
Previously, fatty liver disease was primarily seen in individuals with alcohol abuse disorder, but you don’t necessarily have to be a drinker to get it.
Non-alcoholic fatty liver disease (NAFLD) is a liver disease that occurs in the absence of alcohol use. This condition may start due to obesity, metabolic syndrome, diabetes, or excess calorie intake. Excess fat deposits in the tissue of the liver cause it to function abnormally.
Non-alcoholic steatohepatitis, also known as NASH, occurs when NAFLD progresses and inflammation develops. NASH could lead to fibrosis and scarring of the liver known as cirrhosis, which is irreversible. Nearly 25% of US adults have NAFLD while the rate of NASH is lover (1.5 to 6.5%)
NAFLD has also been associated with the development of chronic kidney disease (CKD), which may lead to the need for dialysis in its late stages. Experts believe that some common mechanisms may be at play in both conditions.
Functions of the liver and kidneys:
You need your liver to live! The liver metabolizes macronutrients (fats, carbs, and protein), stores carbohydrate as glycogen, and detoxifies medications and unwanted foreign material in the body. Your liver also impacts immunity and aids in blood clotting.
Another function of the liver is bile production to aid in fat digestion. The liver is even responsible for cholesterol production, which is why only animal foods contain dietary cholesterol.
Our kidneys help eliminate toxins from the body, as well as manage acid-base balance, blood pressure, and fluid balance. Keeping kidneys healthy involves normalizing blood pressure, controlling diabetes, and managing weight.
Who is at risk for fatty liver disease?
As the rates of obesity and diabetes increase in the US, so do rates of fatty liver disease. NAFLD is seen in up to 75% of overweight and obese adults and in over 90% of those dealing with severe obesity.
CKD impacts adults over the age of 65 more often than younger adults. Roughly 15% of US adults have CKD, according to the CDC.
As mentioned above, conditions that impact the risk for NAFLD also raise the risk of CKD. Insulin resistance, obesity, diabetes, inflammation, and oxidative stress can also be at play in the development of CKD. Fructose consumption -- in the form of high fructose corn syrup -- impacts risk for both conditions
NAFLD may also be present in children. A recent estimate by the CDC suggests nearly 10% of US children have fatty liver disease. The risks for developing NAFLD and CKD increase as we age.
Pregnancy may also induce fatty liver disease in some women, although this is rare. A high-fat, Western diet plays a role in the development of fatty liver disease as well.
An unhealthy gut microbiome may also increase risk of fatty liver disease. Some experts believe that translocation of bacteria in the gut may lead to inflammation of the liver, making it more susceptible to fat deposition.
Lifestyle changes and fatty liver disease
Fatty liver disease is reversible through lifestyle habits including regular exercise, weight loss and dietary changes. A Mediterranean diet along with exercise guidance has been found to aid in the reduction of elevated liver enzymes (a sign of fatty liver disease) as well as liver stiffness.
Scientists believe that the antioxidants, polyphenols, and high fiber content of a Mediterranean diet may be responsible for improvements with fatty liver diseases.
A meta-analysis of over 1070 subjects found that both aerobic and resistance training exercises were equally beneficial in reducing elevated liver enzymes seen in fatty liver disease. In addition, a moderate carbohydrate diet and/or low-fat diet aid in reducing triglycerides, which tend to be high in patients with fatty liver disease.
Uric acid accumulation is present in both NAFLD and CKD. Reducing or avoiding alcohol, which increases uric acid levels, is important to the prevention of both conditions. Purines founds in high-fat meats, organ meat, seafood, and beer also raise uric acid in the blood. These are commonly avoided when a person has gout.
An apple a day may keep fatty liver at bay. Apples are a source of quercetin, an anti-oxidant also found in onions. Quercetin supplementation has been shown to reduce liver enzymes and improve type 2 diabetes-related cellular alterations in liver tissue in mice studies. It may also have anti-inflammatory properties that improve liver function.
What to tell your clients with fatty liver disease:
- Reduce alcohol intake or stop drinking. As alcohol is toxic to both liver and kidneys, it may further exacerbate fatty liver disease and risk for CKD.
- Lose weight if overweight or obese. This helps reduce fat deposition in the liver and may aid in diabetes management.
- Follow a low-fat diet. Reduce intake of fried food, fast food, full-fat dairy products, fatty meats, and heavy desserts.
- Increase the fiber in your diet with beans, lentils, whole grains, fruits, and vegetables. Add oats, fresh fruit, barley, and beans to your eating pattern, all of which are sources of soluble fiber. These foods also aid in blood pressure management to help reduce risk of CKD.
- Get moving. Regular exercise aids in “waist reduction,” which may help reduce the risk and progression of fatty liver disease.
By Lisa Andrews, MEd, RD, LD
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Stephanie Ronco has been editing for Food and Health Communications since 2011. She graduated from Colorado College magna cum laude with distinction in Comparative Literature. She was elected a member of Phi Beta Kappa in 2008.