Soda consumption and hospital admissions among Californian adults with asthma

Dietary digestible carbohydrates are associated with higher prevalence of asthma in humans and with aggravated lung allergic inflammation in mice

BACKGROUND

Dietary carbohydrates and fats are intrinsically correlated within the habitual diet. We aimed to disentangle the associations of starch and sucrose from those of fat, in relation to allergic sensitization, asthma and rhinoconjuctivitis prevalence in humans, and to investigate underlying mechanisms using murine models.

METHODS

Epidemiological data from participants of two German birth cohorts (age 15) were used in logistic regression analyses testing cross-sectional associations of starch and sucrose (and their main dietary sources) with aeroallergen sensitization, asthma and rhinoconjunctivitis, adjusting for correlated fats (saturated, monounsaturated, omega-6 and omega-3 polyunsaturated) and other covariates. For mechanistic insights, murine models of aeroallergen-induced allergic airway inflammation (AAI) fed with a low-fat-high-sucrose or -high-starch versus a high-fat diet were used to characterize and quantify disease development. Metabolic and physiologic parameters were used to track outcomes of dietary interventions and cellular and molecular responses to monitor the development of AAI. Oxidative stress biomarkers were measured in murine sera or lung homogenates.

RESULTS

We demonstrate a direct association of dietary sucrose with asthma prevalence in males, while starch was associated with higher asthma prevalence in females. In mice, high-carbohydrate feeding, despite scant metabolic effects, aggravated AAI compared to high-fat in both sexes, as displayed by humoral response, mucus hypersecretion, lung inflammatory cell infiltration and T_H 2-T_H 17 profiles. Compared to high-fat, high-carbohydrate intake was associated with increased pulmonary oxidative stress, signals of metabolic switch to glycolysis and decreased systemic anti-oxidative capacity.

CONCLUSION

High consumption of digestible carbohydrates is associated with an increased prevalence of asthma in humans and aggravated lung allergic inflammation in mice, involving oxidative stress-related mechanisms.

High fructose corn syrup, excess-free-fructose, and risk of coronary heart disease among African Americans- the Jackson Heart Study

BACKGROUND

Researchers have sought to explain the black-white coronary heart disease (CHD) mortality disparity that increased from near parity to ~ 30% between 1980 and 2010. Contributing factors include cardiovascular disease prevention and treatment disparities attributable to disparities in insurance coverage. Recent research suggests that dietary/environmental factors may be contributors to the disparity. Unabsorbed/luminal fructose alters gut bacterial load, composition and diversity. There is evidence that such microbiome disruptions promote hypertension and atherosclerosis. The heart-gut axis may, in part, explain the black-white CHD disparity, as fructose malabsorption prevalence is higher among African Americans. Between 1980 and 2010, consumption of excess-free-fructose-the fructose type that triggers malabsorption-exceeded dosages associated with fructose malabsorption (~ 5 g-10 g), as extrapolated from food availability data before subjective, retroactively-applied loss adjustments. This occurred due to an industrial preference shift from sucrose to high-fructose-corn-syrup (HFCS) that began ~ 1980. During this period, HFCS became the main sweetener in US soda. Importantly, there has been more fructose in HFCS than thought, as the fructose-to-glucose ratio in popular sodas (1.9-to-1 and 1.5-to-1) has exceeded generally-recognized-as-safe levels (1.2-to-1). Most natural foods contain a ~ 1-to-1 ratio. In one recent study, ≥5 times/wk. consumers of HFCS sweetened soda/fruit drinks/and apple juice-high excess-free-fructose beverages-were more likely to have CHD, than seldom/never consumers.

METHODS

Jackson-Heart-Study data of African Americans was used to test the hypothesis that regular relative to low/infrequent intake of HFCS sweetened soda/fruit drinks increases CHD risk, but not orange juice-a low excess-free-fructose juice. Cox proportional hazards models were used to calculate hazard ratios using prospective data of 3407-3621 participants, aged 21-93 y (mean 55 y).

RESULTS

African Americans who consumed HFCS sweetend soda 5-6x/wk. or any combination of HFCS sweetened soda and/or fruit drinks ≥3 times/day had ~ 2 (HR 2.08, 95% CI 1.03-4.20, P = 0.041) and 2.5-3 times higher CHD risk (HR 2.98, 95% CI 1.15-7.76; P = 0.025), respectively, than never/seldom consumers, independent of confounders. There were no associations with diet-soda or 100% orange-juice, which has a similar glycemic profile as HFCS sweetened soda, but contains a ~ 1:1 fructose-to-glucose ratio.

CONCLUSION

The ubiquitous presence of HFCS in the food supply may pre-dispose African Americans to increased CHD risk.

Excess free fructose, apple juice, high fructose corn syrup and childhood asthma risk - the National Children's Study

BACKGROUND

Recent research provides consistent evidence that the unexplained doubling of childhood asthma prevalence (1980-1995), its continued climb and 2013 plateau, may be associated with the proliferation of high-fructose-corn-syrup (HFCS) in the US food supply. The HFCS used in soft drinks has been shown to contain a higher fructose-to-glucose ratio than previously thought. This coincides with a preference shift from orange to apple juice among young children. Apple juice naturally contains a high (≥2:1) fructose-to-glucose ratio. Thus, children have received high excess-free-fructose doses, the fructose type associated with fructose malabsorption. Unabsorbed excess-free-fructose in the gut may react with dietary proteins to form immunogens that bind asthma mediating receptors, and/or alter the microbiota towards a profile linked to lung disorders. Studies with longitudinal childhood data are lacking. Therefore, we tested the hypothesis that excess-free-fructose intake is associated with childhood asthma risk.

METHODS

Cox regression models were used to analyze prospective early childhood data (12-30 months of age) from the National Children's Study. Intake frequencies for soda/sports/fruit drinks, and 100% juices were used for analyses.

RESULTS

Greater consumption of 100% juice, soda/sports/fruit drinks, and any combination, was associated with ~two (P = 0.001), ~ 2.5 (P = 0.001), and ~ 3.5 times (P < 0.0001) higher asthma incidence.

CONCLUSIONS

Given these results, prior research and case-study evidence, it is reasonable to suggest that the two-fold higher asthma risk associated with 100% juice consumption is due to apple juice's high fructose-to-glucose ratio, and that the ~ 2.5/~ 3.5 times higher risk associated with soda/sports/fruit drinks intake is with the excess-free-fructose in HFCS.

Structural and Social Determinants of Health in Asthma in Developed Economies: a Scoping Review of Literature Published Between 2014 and 2019

Purpose of Review

Using the WHO Conceptual Framework for Action on the Social Determinants of Health, this review provides a discussion of recent epidemiologic, mechanistic, and intervention studies of structural and social determinants of health and asthma outcomes covering the period from 2014 to 2019.

Recent Findings

A majority of studies and interventions to date focus on the intermediary determinants of health (e.g., housing), which as the name suggests, exist between the patient and the upstream structural determinants of health (e.g., housing policy). Race/ethnicity remains a profound social driver of asthma disparities with cumulative risk from many overlapping determinants. A growing number of studies on asthma are beginning to elucidate the underlying mechanisms that connect social determinants to human disease. Several effective interventions have been developed, though a need for large-scale policy research and innovation remains.

Summary

Strong evidence supports the key role of the structural determinants, which generate social stratification and inequity, in the development and progression of asthma; yet, interventions in this realm are challenging to develop and therefore infrequent. Proximal, intermediary determinants have provided a natural starting point for interventions, though structural interventions have the most potential for major impact on asthma outcomes. Further research to investigate the interactive effect of multiple determinants, as well as intervention studies, specifically those that are cross-sector and propose innovative strategies to target structural determinants, are needed to address asthma morbidities, and more importantly, close the asthma disparity gap.

[Asthma and obesity in adults]

Asthma is a chronic inflammatory airway disorder characterized by a multitude of phenotypes. Epidemiological studies show an increase in asthma prevalence in obese patients regardless of age. The association of asthma and obesity is now considered as a phenotype with its own clinical, biological and functional characteristics. Regarding the pathophysiology of asthma and obesity, numerous factors such as nutrition, genetic predisposition, microbiome, ventilatory mechanics and the role of adipose tissue have been identified to explain the heterogeneous characteristics of patients with asthma and obesity. In adult patients with asthma and obesity, respiratory symptoms are particularly prominent and atopy and eosinophilic inflammation is uncommon compared to normal weight asthma patients. Obese asthma patients experience more hospitalizations and use more rescue medications than normal weight asthmatics. Management of asthma in obese patients is complex because these patients have less response to the usual anti-asthmatic treatments. Weight loss through caloric restriction combined with exercise is the main intervention to obtain improvement of asthma outcomes. Bariatric surgery is an invasive procedure with interesting results.

Association between Soft Drink Consumption and Asthma among Qatari Adults

We aimed to examine the association between soft drink consumption and asthma and lung function among Qatari adults. In the cross-sectional study, we used data from 986 Qatari participants aged 20 years and above attending the Qatar Biobank Study. Usual consumption of soft drink was assessed using a food frequency questionnaire. Lung function was measured by spirometry and asthma was based on self-report. The associations between soft drink consumption and asthma and lung function were assessed using multivariable logistic and linear regression, respectively. In total, 65 participants out of 986 (6.6%) reported having asthma. A clear dose-response relationship between soft drink consumption and asthma was found. High soft drink consumers (≥7 times/week) were 2.60 (95% CI 1.20–5.63) times more likely to have asthma as compared to non-consumers. The association was partly mediated by BMI and inflammation. Diet soft drink consumption was positively associated with asthma (OR 1.12 (95% CI 1.02–1.23)) but not with lung function. Regular soft drink consumption was inversely associated with FEV1, but not with FVC. In conclusion, soft drink consumption is positively associated with asthma in Qatari adults. The association is partly mediated by obesity and inflammation. Limiting soft drink consumption should be taken into consideration for asthma prevention.

Health risk behaviors, violence exposure, and current asthma among adolescents in the United States

BACKGROUND

Asthma may worsen during adolescence, due to both health risk behaviors and psychosocial stressors commonly encountered during this life stage.

METHODS

Cross-sectional study of 24 612 high school students who participated in the 2009 and 2011 National Youth Risk Behavior Survey. Multivariable logistic regression was used to examine the relation between self-reported health risk behaviors or psychosocial stressors and current asthma. Mediation analysis was performed to assess whether depressive symptoms or suicidal behavior contribute to the link between psychosocial stressors and asthma.

RESULTS

Current asthma was reported by 13.1% of the study participants. In a multivariable analysis, female sex, obesity, shorter sleep duration, frequent soda/pop consumption, and marijuana use were each significantly associated with 14-36% increased odds of asthma. Any violent behavior (adjusted odds ratio [OR] = 1.12, 95% confidence interval [CI] = 1.02-1.24), any victimization (OR = 1.43, 95%CI = 1.29-1.58), any suicidal behavior (OR = 1.41, 95%CI = 1.22-1.64) and having felt sad or hopeless in the past year (OR = 1.57, 95%CI = 1.40-1.75) were each associated with current asthma. In a mediation analyses, having felt sad/hopeless and suicidal behaviors accounted for 21% and 14%, respectively, of the victimization-asthma association.

CONCLUSION

Potentially modifiable risk factors, including obesity, short sleep duration, frequent soda/pop consumption, and psychosocial stressors are associated with asthma in US adolescents. Promoting healthier lifestyles, as well as screening for violence exposure and treating depressive symptoms, could help reduce asthma burden in this population.