Exercise Prevents Fatty Liver Disease

(October 30, 2008) - It's easy to go to the gym on a regular basis right after you buy the gym membership. (Read about "Getting Started on Fitness") It's also easy to skip the gym one day, then the next day and the day after that. A new study indicates that the negative effects of skipping exercise can occur in a short period. The researchers found that a sudden transition to a sedentary lifestyle can quickly lead to symptoms of nonalcoholic fatty liver disease (hepatic steatosis), which affects at least 75 percent of obese people. (Read about "The Liver" "Obesity")

"We found that the cessation of daily exercise dramatically activates specific precursors known to promote hepatic steatosis," said Jamal Ibdah, one of the researchers. "This study has important implications for obese humans who continually stop and start exercise programs. Our findings strongly suggest that a sudden transition to a sedentary lifestyle increases susceptibility to nonalcoholic fatty liver disease."

Nonalcoholic fatty liver disease is a reversible condition that causes fat to accumulate in liver cells of obese people. As Westernized societies are experiencing a weight gain epidemic, the prevalence of the disease is growing, Ibdah said.

In the study, researchers gave obese rats access to voluntary running wheels for 16 weeks. Scientists then locked the wheels, and transitioned the animals to a sedentary condition. After 173 hours, or about seven days, the rats began showing signs of factors responsible for promoting hepatic steatosis. In the animals tested immediately at the end of 16 weeks of voluntary running, there were no signs of hepatic steatosis.

"Physical activity prevented fatty liver disease by 100 percent in an animal model of fatty liver disease," said Frank Booth, a research investigator. "In contrast, 100 percent of the group that did not have physical activity had fatty liver disease. This is a remarkable event. It is rare in medicine for any treatment to prevent any disease by 100 percent."