Fructose from fruit juice, SSBs tied to higher liver fat content

The consumption of fructose from fruit juice and sugar sweetened beverages (SSBs), but not from fruit, is associated with higher intrahepatic lipid (IHL) content, according to data from a cross-sectional study presented at EASD 2021.

“There has been a long debate on whether dietary fructose is a modifiable risk factor of nonalcoholic fatty liver disease (NAFLD), which is a risk factor for end-stage liver disease, type 2 diabetes (T2D), and cardiovascular disease. [As such, we aimed] to assess the association between habitual fructose intake and IHL content at population level,” said Amée Buziau from the Maastricht University, The Netherlands, during her virtual presentation.

“[W]e found that the intake of fructose from fruit juice and SSBs is independently associated with higher IHL content in a large, extensively phenotyped, population-based cohort. However, fructose from fruit was not associated with IHL,” she continued.

In the fully adjusted model* (model 5), individuals in the highest tertile (T3) of fructose from fruit juice and SSBs had a 1.04- and 1.09-fold higher IHL when compared against the lowest tertile (p_trend=0.019 and 0.009, respectively). [EASD 2021, abstract 86]

Conversely, total fructose intake in T2 and T3 (median, 35.1 and 47.6 g/day) was associated with lower IHL in the crude analysis (model 1; p_trend<0.001). This association remained after adjusting for age, sex, and T2D (model 2; p_trend<0.001) and, additionally, for lifestyle factors** (model 3; p_trend<0.001). However, these were lost following additional adjustments for nutritional factors*** tied to IHL (model 4; p_trend=0.903) and in model 5 (p_trend=0.647).

Similarly, fructose intake from fruit was associated with lower IHL (p_trend<0.001 [models 1, 2, and 3]). The strength of the association was attenuated in model 4 (p_trend=0.044) and was completely lost in model 5 (p_trend=0.767).

Buziau and colleagues arrived at these results using data from the Maastricht study. Habitual fructose intake in 3,981 individuals (median age 60 years, 50 percent female, 20 percent with T2D) over the past 12 months was estimated using a customized validated food frequency questionnaire. Median total fructose intake was ~36 g/day and median IHL was 3.2 percent.

Buziau attributed the divergent associations between IHL and the different fructose sources to the “food matrix and the abrogation of the inverse association of fructose from fruit with IHL after adjustment for dietary fibre”. Moreover, fruit consumption could be considered a part of a healthy lifestyle. “Although we extensively corrected for lifestyle variables, residual confounding may still be present and partly account for the current observations.”

Small changes, big benefits

“[Evidence shows that] individuals in the highest tertile of fructose intake from SSBs who reduced their intake to the lowest tertile intake (~4.5 g/day) may reduce their IHL by 0.3-percent point,” said Buziau. Although this reduction seems small, this correlates with data reflecting a 0.7-percent IHL reduction in overweight adults with a high fatty liver index following a 6-week fructose-restricted diet. [Am J Clin Nutr 2021;113:391-400]

“[This] small reduction in IHL should be viewed in the context of the global NAFLD epidemic,” highlighted Buziau. With NAFLD affecting about a quarter of the global adult population, reducing the intake of fruit juice and SSBs may translate to major health benefits. “[Reducing] intake of fructose-containing beverages …. [is] a relatively easy change in lifestyle … [that could] prevent hepatic steatosis and cardiometabolic disease at population level,” concluded Buziau.