Dietary Sources of Fructose and Its Association with Fatty Liver in Mexican Young Adults

Nutrients 2019, 11, 522; doi:10.3390/nu11030522 —

Cantoral A, Contreras-Manzano A, Luna-Villa L,
et al.

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  • To
    assess the consumption of dietary fructose according to: 1) classification
    of hepatic steatosis by two indexes and 2) diagnosis of NAFLD by MRI.


  • Previous studies have shown that consumption of
    fructose through soft drinks and other beverages is higher in NAFLD
    patients than in controls.
  • Mexico has one of the highest per capita intake
    of soft drinks worldwide and their consumption is particularly high in the
    19 to 29 year-old age group.
  • The present study sought to compare the intakes
    of different dietary sources of fructose in relation to two liver indexes
    that predict hepatic steatosis and the identification of NAFLD by MRI in
    young adults in Mexico.


  • A cross-sectional analysis was performed in a
    sample of 100 healthy young adults living in Mexico City between October
    of 2016 and May of 2017. Participants were selected from the Early Life
    Exposure in Mexico to Environmental Toxicants (ELEMENT) cohort study.
  • For the present study, participants were
    evaluated during a weekend day at the research center after 10 hours of
    fasting. A blood sample and anthropometric measures were obtained. In
    order to estimate the hepatic triglyceride content, proton magnetic
    resonance spectroscopy (PMRS) was performed. Also, a trained nutritionist
    administered a validated semi-quantitative food frequency questionnaire
    (FFQ) and a lifestyle questionnaire.
  • Measurement of liver fat content and diagnosis
    of NAFLD was made by MRI, and a fasting blood sample was obtained to
    quantify glucose, triglycerides and hepatic enzymes (ALT, AST, GGT) using
    a bench clinical chemistry analyzer. 
    The Hepatic Steatosis Index (HSI) was estimated using the ALT/AST
    ratio, BMI, sex, and impaired fasting glucose (IFG) blood levels (>110


  • The study sample had a mean age of 21 years,
    54% were male, 52% were classified as low SES and 56% of participants were
    not physically active.
  • According to the MRI, 18% of the participants
    had the diagnosis of NAFLD (>5% of triglyceride content in the hepatocytes),
    and according to HSI and FLI, 44% and 46% of the participants presented hepatic
    steatosis, respectively.
  • The comparison between the true positive
    participants and the healthy participants showed that the true positive
    participants had an elevated risk in almost all the parameters in a higher
    level.  When comparing those
    classified as false positive versus those in the healthy category, BMI was
    2.3 to 3 times higher in the false positive group according to the HSI and
    FLI, respectively.
  • For the false positive participants in the FLI
    the risk is significantly higher in the variable ALT (RRR = 1.10, 95%CI
    1.02–1.20) compared to healthy participants.
  • For the total sample, dietary information
    showed that the median energy intake was 2689 Kcal with approximately 56%
    of the calories from carbohydrates, 33% from lipids, and 13% from proteins.
    The median intake of SSB was 720 mL, with the main contributor to SSB
    being soda (specifically cola-type) which contributed 45% of the total
    SSB, followed by sugar-sweetened commercial fruit beverages and home-made
    fruit beverages with 22%.
  • Those with negative FLI (score < 30)
    consumed statistically less energy (kcal) and total grams of carbohydrates
    per day, but also reported consuming more calories from proteins and
    lipids as a percentage of the total calories, compared to those classified
    as positive FLI (score ≥ 30) and also compared to those classified as
    false positives.
  • The dietary intake of almost all dietary
    sources of fructose were higher in those classified with steatosis by both
  • When the consumption of the different beverages
    included in the SSB category was compared, the soda intake was
    statistically higher in FLI false positive than in negative subjects.  In the case of those classified as NAFLD,
    the median intake of natural fruit juices was statistically higher
    compared to those classified as non-NAFLD (146 versus 0 mL/day).


  • Sugar-sweetened beverages (SSB) and juices were
    consumed significantly more by those with steatosis by FLI and NAFLD
    suggesting that SSB intake is linked to metabolic alterations that predict
    the risk of having NAFLD at a young age.
  • This study adds to the existing evidence
    linking SBB intake with NAFLD, a disease that is increasing in
    Mexico.  Therefore, more public
    health action is needed to reduce the intake of fructose, as sucrose or
    HFCS, especially from SSB that are highly consumed in Mexico and in other populations.
  • As obesity is currently one of the biggest
    health problems in Mexico, and it is related to the incidence of NAFLD,
    more studies are needed to measure the prevalence of NAFLD in relation to
    dietary components.

Points to Consider

  • The limited sample size and the cross-sectional nature of this
    analysis limits the ability to draw conclusions regarding the effect of increased
    fructose consumption, mainly through SSB, on the natural history or progression
    of NAFLD in this population.
  • It is possible that other lifestyle factors, such as overall diet,
    obesity and sedentary behavior, may have an equal of higher effect on NAFLD
    classification. Given the design of this study, it is not possible to isolate
    the effect of a single factor. Further, no conclusions about cause and effect
    can be drawn.