Non-alcoholic fatty liver disease (NAFLD), a common condition linked to obesity and heart disease long thought to weaken health and longevity, poses no excess risk for death, a new study has claimed.
Mariana Lazo and her colleagues from the Johns Hopkins University School of Medicine's Welch Center for Prevention, Epidemiology, and Clinical Research, used health information collected from 11,371 Americans between 1994 and 1998 and followed for up to 18 years as part of the Third National Health and Nutrition Examination Survey (NHANES III).
The researchers checked liver enzyme levels and ultrasound tests for evidence of NAFLD, and ultimately looked at death rates associated with NAFLD.
The participants ranged in age from 20 to 74 during the data collection years.
Since the ultrasounds were originally taken to assess gallbladder health, the researchers looked at each recording to determine the presence of fat in each person's liver.
"Physicians have considered fatty liver disease a really worrisome risk factor for cardiovascular disease," Lazo said.
"Our data analysis shows this doesn't appear to be the case. We were surprised to say the least because we expected to learn by how much non-alcoholic fatty liver disease increased the risk of death and instead found the answer was not at all," she said.
They found that there was no increase in mortality among those with NAFLD, which was identified in approximately 20 percent of the NHANES participants.
At the end of the follow-up period, mortality from all causes was 22 percent, or 1,836 individuals, and cardiovascular disease was the cause of death for 716 participants, cancer for 480 and liver disease for 44.
The study has been recently published online in BMJ, the British medical journal.