Excess free fructose, high-fructose corn syrup and adult asthma: the Framingham Offspring Cohort

British Journal of Nutrition (2018), 119, 1157–1167; doi:10.1017/S0007114518000417 — DeChristopher LR, Tucker KL. — Download PDF

Objective:

  • To test the hypothesis that consumption of HFCS-sweetened soda, fruit drinks and apple juice, but not orange juice or diet soda, increases asthma risk, independently of potential confounders.

Background:

  • There is growing evidence that intakes of high-fructose corn syrup (HFCS), HFCS-sweetened soda, fruit drinks and apple juice – a high-fructose 100% juice – are associated with asthma.
  • It is possible that this is due to the high fructose: glucose ratios and underlying fructose malabsorption which may contribute to enteral formation of pro-inflammatory advanced glycation end products, which bind receptors that are mediators of asthma.
  • Though there is a large amount of research in this area, epidemiological studies with longitudinal data are lacking.

Methods:

  • Survival analysis was conducted with longitudinal data from the Framingham Heart Study-Offspring cohort (FHS-OS). Participants were adult, predominantly non-Hispanic White men and women, with a mean age of 47.9 years. Thirty-nine percent were overweight and 17% were obese at baseline.
  • Participants were medically examined and responded to health questions approximately every 4 years, with the exception of an 8-year gap between examinations 1 and 2. Food and beverage intake frequency was obtained via the Willett Food Frequency Questionnaire (FFQ), beginning with the third examination.
  • The current study focused on data examinations 3-7, between the years 1984-2001.  There were between 2692 and 2696 participants with complete responses to analyses questions, depending upon the beverage.
  • The Intake frequency of non-diet soda, fruit drinks, apple juice and any combination of these beverages as self-reported at each examination via the Willett FFQ was analyzed. Incident asthma, defined as self-reported asthma, including wheezing or asthma since the previous examination of short or long duration, or with respiratory infections, was also analyzed.

Findings:

  • Increased consumption of all sugar-containing beverages was associated with higher total energy intakes.
  •  Greater intake of any combination of HFCS-sweetened soda, fruit drinks and apple juice was significantly associated with progressively higher asthma risk, rising from 59% higher for moderate (2–4 times/week) consumers to a plateau of 89% higher among 5–7 times/week as compared to never/seldom consumers, independent of potential confounders including age, sex, BMI, smoking, education level and total energy intake.
  • Regular (5–7 times/week) consumers of HFCS-sweetened soda had a 48% higher asthma risk compared with never/seldom consumers, independent of potential confounders.
  • Moderate consumers (2–4 times/week) of fruit drinks had 58% higher asthma risk and moderate consumers of apple juice had 61% higher asthma risk, compared with never/seldom consumers, independent of sex, age, smoking history, education level, BMI and total energy intake.  There was no association between diet soda or orange juice intake and asthma.

Conclusions:

  • Moderate and frequent consumption of HFCS-sweetened soda, fruit drinks and apple juice, but not diet soda or orange juice, increased asthma risk, independent of age, sex, smoking, BMI, education level, total energy intake and T2D.
  • Recommendations to reduce sugar-sweetened beverage consumption may be inadequate to address asthma risk, as associations are evident even with moderate intake of apple juice – a 100% juice.
  • Intervention studies and more research of consequences of fructose malabsorption are needed.

Points to Consider:

  • Outcomes were based on self-report, which is subject to reporting bias.
  • A myriad of foods contribute to fructose and HFCS intake (cold cereals, breads, snack bars, desserts, sweets, ketchup, sauces, etc), which were not accounted for in this study.
  • This study is not nationally representative. Participants were mainly non-Hispanic white Americans, which does not allow consideration of race/ethnicity on this relationship.
  • Income and occupational/environmental air quality, possible confounders, were not accounted for in this study.