This 2018 paper published in the Journal of Hepatology reviews the evidence linking fructose and sugar-sweetened-beverage (SSB) consumption to nonalcoholic fatty liver disease (NAFLD). Fructose and SSB consumption correlates with NAFLD incidence and progression: Children and adults who consume more have higher risk of NAFLD, and patients with NAFLD (and with more severe disease progression) tend to consume more sugar than their peers.
Figure 1: Association of added-sugar consumption with rates of nonalcoholic fatty liver disease (NAFLD), obesity in National Health and Nutrition Examination Survey (NHANES) data.
Fructose promotes fat accumulation in the liver through multiple mechanisms, increasing fat production (de novo lipogenesis); decreasing fatty-acid oxidation; and driving direct and downstream consequences in the liver, gut and adipose tissue that further increase fat storage and inflammation. These mechanisms demonstrate means by which fructose both increases risk for liver steatosis (excessive fat storage in liver tissue) and more severe forms of the disease resulting from fibrosis (including nonalcoholic steatohepatitis—NASH—and eventually cirrhosis).
Figure 2: Interaction of fructose, glucose, and polyol pathway with uric acid and triglycerides.
Comments on Fructose and Sugar: A Major Mediator of Non-Alcoholic Fatty Liver Disease
Even if I used to consider myself fit (national team athlete) I used to have problems with my liver enzyme and it only went back to normal when I removed sugar from my diet! It is so important that everyone understands that even if you "look good" because you exercice it doesn't mean you are healthy. You can't out work a bad diet.
I see NAFLD in my pediatric practice. It’s not uncommon. I never saw it 20 years ago. Years ago, when I first saw it, I would refer patients to a GI specialist for a liver biopsy. Now I don’t refer, but instead educate on the role of sugar. And I see it resolve with changes in nutrition.
This article highlights the role fructose and sugar sweetened beverages (SSB) play on the development of NAFLD (independent of overnutrition and sedentary lifestyle). Which is very important. SSBs are the leading source of added sugar intake in the US.
https://www.cdc.gov/nutrition/data-statistics/sugar-sweetened-beverages-intake.html
Daily soda consumption amongst high school students is 20%.
https://www.cdc.gov/mmwr/volumes/66/wr/mm6604a5.htm?s_cid=mm6604a5_x
So if we want to prevent and treat NAFLD, we need to limit fructose, especially from SSBs. The AAP has made recommendations to limit sodas in the classroom, limit soda for obesity, avoid sports and energy drinks, and limit juice (age specific recommendations). But we need to have a global recommendation that SSBs are harmful universally (all types, all ages, all locations).
Working with patients to make healthy choices can be very difficult. Many factors play a role including compliance and socioeconomics. But it’s very simple, and cheap, to have (my pediatric) patients limit drinks to water and unsweetened milk.
The pathways are complex and not always intuitive but the take home message is clear. Avoid added fructose and glucose. While your at it, avoid all added sweeteners. They are designed to addict you and not to nourish you.
Fructose and Sugar: A Major Mediator of Non-Alcoholic Fatty Liver Disease
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