Alcohol tends to be associated with the mere mention of liver complications, but the name of this disease, nonalcoholic fatty liver disease (NAFLD), doesn’t leave room for any misplaced fault. As with obesity, Type 2 diabetes, and heart disease, a diet high in saturated fats, sugar, and processed foods increases one’s chances of developing NAFLD significantly. NAFLD is defined by an overabundance of accumulated fat in liver cells, hence the word “fatty” in the name of the disease. Though it is normal for a small amount of fat cells to be present in the liver, it becomes an issue when fat cells account for 5 to 10 percent of the liver’s weight.1 This is the most common cause of liver diseases, such as cirrhosis, liver cancer, and liver failure.2
Currently, 30 to 40 percent of Americans have NAFLD, according to the American Liver Association.1-3 Worldwide, it affects 25 percent of the population.2 Researchers predict that by the year 2030, NAFLD will be the primary reason for liver transplants in the United States.3
Symptoms of nonalcoholic fatty liver disease may not be noticeable at first, but can include fatigue, weakness, weight loss, loss of appetite, nausea, abdominal pain, jaundice, fluid build-up and swelling of the legs and abdomen, and confusion.1
A blood test can detect simple fatty liver, which is the first stage of NAFLD and is reversible if treated promptly. Liver function and lipid panel blood tests, thought, aren’t typically part of standard bloodwork and likely will have to be requested by a doctor. If the results of the blood work are abnormal, and other liver conditions, such as hepatitis, are ruled out, the doctor may request a liver biopsy to determine the severity of liver damage.1
The second, more serious stage of NAFLD is non-alcoholic steatohepatitis, or NASH, which causes the liver to become inflammed, causing more injury. Someone with NASH might notice a dull aching pain on the top right of their abdomen. Twenty percent of people with NAFLD will progress to NASH.2
If not managed, NASH can progress to the third stage of NAFLD—fibrosis— this is when the persistant inflammation seen with NASH causes fibrous scar tissue to form on the liver. The fourth and final stage of NAFLD is cirrhosis, in which the continually increasing bands of scar tissue cause the liver to shink and eventually stop working altogether.4a
The relation to lifestyle choices explains why NAFLD is so common in those who are overweight or obese, have been diagnosed with Type 2 diabetes, and/or have high cholesterol and triglycerides.5 Additionally, individuals with NAFLD have an increased rate of heart disease.4,5 Cardiovascular events (heart attack, heart failure) are the most common cause of death4 in patients with NAFLD. Adults between the ages of 40 and 60 years also maintain an increased risk of developing the disease.1 Understanding the correlation between lifestyle choices and NAFLD is integral to management and prevention.
The liver is responsible for processing and converting what we eat and drink into energy and nutrients.1 So, it should come as no surprise that the food we eat can have such a great impact on the organ.
The link between poor dietary habits and risk of liver damage was highlighted for the general public by the experimental documentary “Super-Size Me.” Director and test subject Morgan Spurlock ate food soley from the fast food restaurant chain McDonald’s for 30 days straight to showcase the typical dietary habits of many Americans as well as the significant level of influence the fast food industry has had on the American diet. And, in doing so, Spurlock put himself at risk for some of the typical diseases many Americans develop from eating such a diet. As expected, by the end of the experiment, his cholesterol, weight, and blood pressure had all increased, as well as his liver enzymes; the fast food caused his liver to become “fatty.”
Not too long after the documentary was released, a study conducted by the University Hospital of Linköping, Sweden, demonstrated how consuming fast food for two meals a day, combined with a sedentary lifestyle, began to cause liver damage in their test subjects in just one week.6 The subjects had not only gained weight, but damaged their liver and increased their chances of developing NAFLD.
Fast food is a leading culprit for the progression of liver damage because of its high saturated fat and sugar content.7 The saturated and trans fats and sugar in food independently, or in conjunction with, preexisting conditions such as overweight or obesity, T2DM, insulin resistance, high blood pressure, and high levels of fat in the bloodstream, promote the accumulation of fat in the liver.7
This is why healthy eating is a method that overlaps both management and prevention. Since higher saturated fat and sugar intakes are related to the progression and development of NAFLD,5-8 it makes sense that significantly reducing or eliminating consumption of the above can counteract the negative effects. Animal products, including meats, eggs, and dairy, contain higher levels of saturated and trans fats and cholesterol than whole, plant-based foods.8 Decreasing or eliminating consumption of food derived from animals while increasing consumption of whole, plant-based foods allows the intake of more fiber and nutrients. High soluble fiber (beans, oats), nuts, soy protein, and foods with phytosterols (most vegetables) are cholesterol-lowering foods9,10 that do not accumulate in the liver. In fact, a plant-based diet has been associated with lowering the risk of NAFLD9 and improving liver function, along with many other benefits.9-12
Compared to people who eat meat and/or fish regularly, people who primarily consume plant-based foods tend to have lower levels of HDL cholesterol,12 lower risks of developing diabetes and heart disease, and lower body weights. Weight reduction, along with a plant-based diet, has been shown through research to reduce liver swelling and improve abnormal liver enzyme levels.11,12 Integrating physical activity as part of a healthy lifestyle can also reduce the risk of developing NAFLD.1 (Note: Very rapid weight loss can be dangerous and lead to inflammation of the liver and fibrosis in patients with obesity and NAFLD.5 )
Though the instant gratification of fast food might be appealing when we are in a hurry or perhaps strictly to indulge our taste buds, the ramifications of consuming highly processed food that is high in saturated fats and sugar seem to outweigh any convenience of time, so to speak. If we all made conscious efforts to achieve a healthier lifestyle that includes more whole, plant-based foods and physical activity, the worldwide persistence of NAFLD could be halted.
