A SNP on the Adiponutrin (PNPLA3) gene has been linked to fatty liver infiltration and metabolic complications. Factors promoting deposition of fat in the liver include Obesity, Type 2 Diabetes, insulin resistance and alcohol ingestion. It is therefore no surprise that Non-alcoholic fatty liver disease (NAFLD) is one of the most common diseases in western countries due to a rapid rise in obesity and the Metabolic syndrome. A recent study found a significant correlation between a C>G substitution on the PNPLA3 gene and hepatic fat content (Romeo et al 2008). There was also a significant correlation between this SNP and hepatic inflammation. Hepatic inflammation in turn can lead to the development of cirrhosis and chronic liver failure and therefore carriers of this SNP are at an increased risk of developing severe liver disease.
A new study looked at whether the G allele of this SNP influenced the ability of weight-loss to reduce hepatic fat or change insulin sensitivity. The study included 8 subjects who had the G allele and 10 who had the C allele.The subjects were started on a low carbohydrate, low calorie diet for 6 days. The results showed that although weight loss between the two groups was not significantly different, the subjects with the G allele experienced a 45% reduction in hepatic fat in comparison to the C allele who had a 18% reduction. In addition, the G allele had lower fasting insulin levels than those carrying the C allele.
They concluded that weight reduction is effective in reducing hepatic fat in individuals homozygous for both the C and G alleles.
Other studies have recommended the use of antioxidants such as Vitamin E or drugs that reduce insulin resistance to treat NAFLD and avoid the development liver damage. I think that with the economic recession, cheap alcohol (and food) and depression on the rise, the incidence of NASH may even worsen, evidence has shown that the incidence is already increasing rapidly in children. Individuals carrying this polymorphism should be extra vigilant with their weight, diet and alcohol intake.
My recommendations include:
- Eat a healthy balanced diet rich in fruits, vegetables and low in refined sugars.
- Cook your own food, or learn to cook. Avoid eating out
- Be ingredient and label savvy when shopping
- Stick to the recommended units of alcohol and know what a unit is!
- Stay active and maintain a healthy weight