What is Non Alcoholic Fatty Liver Disease

Did you know that around one third of our population are living with Non Alcoholic Fatty Liver Disease?

You may be wondering what is Non Alcoholic Fatty Liver Disease (NAFLD) or how do I know I have it, or what can I do to prevent it?  Nonalcoholic fatty liver disease is an umbrella term for a range of liver conditions affecting people who drink little to no alcohol, or less than 2-3 standard drinks per day. As the name suggests, the main characteristic of NAFLD is too much fat stored in liver cells.  Here we will discuss what NAFLD is, what causes NAFLD, and what you can do to reverse NAFLD.

How common is NAFLD in Australia?
It is estimated that around 30% of the Australian population has NAFLD, with this number increasing to around 75% in people who are obese or have Type 2 Diabetes.

What causes NAFLD?
NAFLD is generally linked to overnutrition, and is strongly associated with

• Overweight or obesity;
  
• Insulin resistance, where your cells do not take up glucose effectively in response to the hormone insulin
  
• High blood glucose level such as in type 2 diabetes; and 
  
• High levels of fats, particularly triglycerides, in the blood
  

What are the symptoms of NAFLD and how is it diagnosed?
NAFLD generally does not cause any symptoms until it progresses to a more advanced form of liver disease, therefore most people do not know that they have the condition unless screened through blood tests or incidental findings through ultrasound.
To accurately diagnose NAFLD, an ultrasound or biopsy is performed.
What are the health consequences of NAFLD?
Individuals with NAFLD have a higher prevalence of coronary heart disease, cerebrovascular disease, such as a stroke, and peripheral vascular disease, with cardiovascular disease being the leading death of patients with NAFLD.  And their risk for cardiovascular disease is independent of any other risk factors for CVD such as stress, smoking, inactivity, etc.
 
What is the treatment for NAFL?
The first line treatment for NAFLD or any liver disease is lifestyle changes and therapy.  This may occur in conjunction with medication management of the person’s other conditions such as diabetes, hypertension or high triglyceride levels.
 
What forms of lifestyle therapy are beneficial?
Weight gain is a major determinant of NAFLD, therefore weight loss is a key goal of treatment, with as little as 2-3% reduction in body weight causing a reduction in liver fats by as much as 20-30%.  However the most benefit and possible reduction of NAFLD is seen with 7-10% of body weight losses.
When looking at the research, neither exercise nor nutrition efforts alone are the most effective, but a combination of both have been shown to have the best effect on weight loss.
However, further research has demonstrated that reductions in liver fat%, along with improvements in other health factors such as triglyceride levels, blood pressure, body fat percentage and improvement in fitness, leading to a reduction in CVD and all cause mortality can be achieved through exercise, independent or regardless of weight loss.  Therefore exercise is a key component of successful treatment of this condition.
 
What exercise is best in treating NAFLD?
There has been various research looking at both aerobic exercise and strength training in the treatment of NAFLD, with aerobic exercise being superior and recommended.
In terms of type, frequency, time and intensity of that aerobic exercise, there have been benefits shown for both moderate and vigorous intensities of varying durations.  
However the general rule is to:
Accumulate 150–300 min per week of moderate‐vigorous‐intensity aerobic exercise, on at least 3 days of the week.   
This could include walking, cycling, running, cross trainer, swimming, type activities raising your heart rate to a minimum moderate level.  
It has also been shown that increasing your intensity and heart rate to higher levels further benefits for your fitness, reduces blood glucose levels and decreases your risk of mortality; and may have better effects in reducing liver fat for people with more advanced liver disease beyond NAFLD.​

Lisa Parkinson
Accredited Exercise Physiologist & Credentialled Diabetes Educator.

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