Fatty livers in teenagers can be helped by eating less sugar

Fatty liver disease (nonalcoholic fatty liver disease NAFLD) has become epidemic in concert with obesity. NAFLD frequently even happens in kids, especially Hispanic kids. I recently attended a lecture on NAFLD given right here by one of our own gastroenterologists, Dr. Imtiaz Alam. He talked about how much we should be worrying about NAFLD and the new ways of diagnosing and measuring it available at Southern Ohio Medical Center. I asked him why we should be spending money and effort on this since there is no treatment for it other than “recommending ‘lifestyle modification to improve diet,’ without support for one specific diet over another because of the limited available evidence.” And anyway everybody should be eating right and exercising more whether they have NAFLD or not. He smiled and said well maybe if they know they had this disease people might be more inclined to follow the lifestyle advice and someday soon there will be some drug treatments available and then we’ll have know how to find and measure it.

One of the possible dietary culprits in this NAFLD epidemic is thought by some to be sugar, especially fructose.

The January 22 issue of The Journal of the American Medical Association has the report of a study that shows that eating less sugar can improve NAFLD in Hispanic adolescent boys.

The investigators for this study from 2 US academic clinical research centers, Emory University, Atlanta and University of California, San Diego, took 40 adolescent teenagers, 95% of whom were Hispanic, with NAFLD, and got half of them to eat a diet low in free sugar. “Free sugar” means added sugar and fruit juices. They got the low free sugar eaters to do this by providing all the meals to their whole family during a 2 month intervention period. The other 20 kids just kept eating whatever they always ate that presumably gave them NAFLD in the first place. Use of artificial sweeteners was prohibited in the intervention group because of “the ongoing controversy regarding their effect on body weight and insulin sensitivity.”

At the end of the 8 week period there was a small improvement in their NAFLD disease but not total cure in the low free sugar boys. Also the low sugar intervention resulted in a weight loss of 3 pounds (1.5%) while the control boys had a weight gain of 1.3 pounds (less than 1%) – a small but statistically significant difference.

So those riding the sugar-is-the-enemy band wagon can add this piece of evidence to their side, but I wonder if achieving the same small weight loss difference by eating a diet that did not restrict sugar would have accomplished the same effect on NAFLD.

1. Schwimmer JB et al. Effect of a low free sugar diet vs usual diet on nonalcoholic fatty liver disease in adolescent boys. JAMA. 2019;321(3):256-65.

2. https://conscienhealth.org/2019/01/sugar-and-liver-disease-in-children/