Most adults would assume that if they avoid drinking an excessive amount of alcohol, their livers will remain healthy. This, though, is far from the truth. The Dallas Heart Study suggests that roughly 30 percent of American adults have nonalcoholic fatty liver disease, which some doctors claim may affect even more — up to five percent more.
Though many doctors attribute the condition's increasing prevalence to swelling rates of obesity and diabetes, the complete story is much more complicated.
Fatty Liver Disease 101
The liver is the second largest organ in the body — skin is considered the largest organ. The liver weighs in at about 3 lbs. and plays a role in many bodily functions, including digestion, metabolism, immunity, and the storage of nutrients. Nonalcoholic fatty liver disease is an abnormal accumulation of fat in the liver of people who drink no or little alcohol.
As described by the American Liver Foundation, if more than five to 10 percent of the liver’s weight is fat, then this would be considered steatosis or ‘fatty liver.’ Although up to 80 percent of fatty liver patients won’t experience any problems as a result of the condition, the remainder may progress to nonalcoholic steatohepatitis. In such cases, the fatty liver becomes inflamed and cells become damaged. Nonalcoholic steatohepatitis can even lead to cirrhosis, a fatal illness in which the liver forms scar tissue and eventually ceases to function.
In Western countries, nonalcoholic fatty liver disease (NAFLD) appears to be increasing with estimates of its prevalence ranging between 20 and 30 percent. Worse, researchers estimate that nearly one out of every 10 children in the U.S. — more than seven million children — has nonalcoholic fatty liver disease. Pediatric NAFLD affects more boys than girls, by a ratio of two-to-one.
Yet, most children and adults show no symptoms or signs of the condition. This was certainly the case with Nick Giordano, whose story is featured by the American Liver Foundation.
No Symptoms, No Signs
“To be honest, at times I still feel funny telling people I have liver disease,” Giordano wrote of his condition. “I feel fine, I look normal and chances are that if I didn’t tell you I had liver disease, you would never know.”
The American Liver Foundation notes that people who are overweight or obese, those with diabetes, high cholesterol, or high triglycerides, are the ones who tend to develop NAFLD. Other factors may lead to the condition as well, including poor eating habits and rapid weight loss. Yet, some people have no risk factors but still develop NAFLD. For example, Giordano was only a few pounds overweight and exercised regularly. He even ran marathons. He only discovered the disease when his primary care physician noticed his liver enzymes were elevated. From there, Giordano visited a specialist, who advised dietary changes, weight loss, and avoidance of even casual alcohol consumption. By following his doctor’s guidelines, his enzymes returned to normal levels in just a few months.
Although he doesn’t know what caused his initial diagnosis of NAFLD, Giordano's grandfather had struggled with liver disease and is considered to be one of the conditions that can increase an individual’s risk. Other risk factors, along with those previously mentioned, include:
- Certain medications
- Gastric bypass surgery
- Metabolic syndrome
- Toxins and chemicals, such as pesticides
- Wilson's disease
One other risk factor may be ethnicity, according to recent studies.
Asians and Hispanics At Increased Risk
Researchers from the University of Chicago conducted a retrospective study to examine the relationship between ethnicity and NAFLD. In comparison to whites, African Americans showed a lower degree of fatty liver while Asians and Hispanics showed a greater tendency than whites and other ethnicities combined. In particular, studies on Mexican-Americans suggest that one gene, PNPLA3, may occur often in the Mexican-American population and may be linked to the condition.
It is important to remember that in the majority of cases, nonalcoholic fatty liver disease will not lead to complications and will not present symptoms. When it is discovered, doctors typically treat the condition by treating the risk factors. For example, in the case of Giordano, his doctor worked to help him eliminate the handful of behaviors — overeating, the occasional drink — that might contribute to the condition. In cases of high cholesterol, patients might be advised to manage their low-density lipoprotein (LDL) levels; in cases of obesity, patients are advised to lose weight.
"Throughout the last few years I have heard countless stories from other liver patients," Giordano noted. "Some have been inspiring and others have been heartbreaking." Having made the necessary changes to correct an issue that potentially may have developed into serious illness, he counts himself lucky to be alive and therefore able to make a difference.
Sources: Bellentani S, Scaglioni F, Marino M, Bedogni G. Epidemiology of non-alcoholic fatty liver disease. Digestive Diseases. 2010.
Mohanty SR, Troy TN, Huo D, et al. Influence of ethnicity on histological differences in non-alcoholic fatty liver disease. Journal of Hepatology. 2009.
Davis JN, Le KA, Walker RW, et al. Increased hepatic fat in overweight Hispanic youth influenced by interaction between genetic variation in PNPLA3 and high dietary carbohydrate and sugar consumption. American Journal of Clinical Nutrition. 2010.