Nonalcoholic Fatty Liver Disease (NAFLD) is characterized by fatty infiltration of the cells that make up the liver (steatosis) in a patient who consumes little to no alcohol. Alcoholic liver disease has a similar presentation but must be distinguished from NAFLD. When the fatty infiltration of liver cells in NAFLD is accompanied by inflammation, the situation is called non-alcoholic steatohepatitis (NASH). NAFLD affects 10-24% of people in various countries and 58-74% of obese individuals. And as you may surmise, risk factors for NAFLD include obesity, type 2 diabetes and elevated triglycerides. Sound familiar? It should, as nutritional choices and lifestyle habits play an important role in its development. Some investigators have even suggested that NAFLD is a feature of the metabolic syndrome!
NASH may progress to liver fibrosis, cirrhosis or hepatic carcinoma. Hepatic steatosis does appear to be a risk factor for cardiovascular disease and is associated with an INCREASED incidence of all cause mortality.
Conventional therapy includes weight loss, controlling cardiovascular disease risk factors such as dyslipidemia and controlling insulin resistance and blood glucose levels. In overweight or obese patients with NASH improvement was seen in liver biopsy samples after the patients underwent dietary changes to lose weight.
Diets high in fructose and/or sucrose have induced fatty liver in rats and ducks. In a study of healthy, non-obese males who consumed a diet containing 20-35% of calories as sucrose or fructose for 30 days, 27% of the participants developed markedly increased levels of liver enzymes suggestive of liver injury. The results of a follow up study indicated that both the high sucrose/fructose consumption and the excess calories played a role. Since glucose has not been implicated in liver disease, it is likely that fructose was the culprit (sucrose is 50% glucose and 50% fructose). High fructose corn syrup from oversized soft drinks have also contributed to the pronounced elevations in liver enzymes that occurred after Morgan Spurlock subjected himself to a MacDonald’s only diet for thirty days (Super-Size Me).
Some patients with celiac disease (gluten allergies) have cellular features in the liver similar to those with NASH. Improvement was noted with a gluten free diet. This association of NAFLD and Celiac disease raises the possibility that allergies to other foods may contribute to the pathogenesis of NAFLD.
The refining of whole wheat flour results in loses of Vitamin E, choline, betaine, Vitamin B6, pantothenic acid, magnesium, zinc and manganese. Each of these nutrients may play a role in the prevention or treatment of NAFLD. In addition, whole grains contain phytate which inhibits the absorption of iron, a mineral that may exacerbate NAFLD. Consuming whole grains instead of refined grains could have a positive impact in patients with this condition.
Trans-fatty acids and brominated vegetable oil (present in Mountain Dew and Gatorade) can result in fatty infiltration of the liver and thus it would be wise for patients with NAFLD to avoid these substances. Whey protein ingestion can results in improved liver function and decreased fatty deposition in the liver in patients with NASH.
So again, our lifestyle choices impact our health and adverse nutritional choices can induce liver disease apart from alcohol. In the next post, I will show the role of nutritional supplements in the prevention and the treatment of NAFLD. Thanks for reading….