Maternal intake of free sugars — mono- or disaccharides added to food or drink by manufacturers or consumers — affects rates of atopy or atopic asthma, but not wheeze, eczema, or hay fever in offspring.1
Annabelle Bédard, PhD, of the Centre for Primary Care and Public Health at the London School of Medicine and Dentistry and Queen Mary University of London, United Kingdom, and colleagues examined the relationship between maternal free sugar intake during pregnancy and both respiratory and atopic outcomes in offspring.1
The population-based cohort study used data collected from the Avon Longitudinal Study of Parents and Children. In total, data from 8956 mother-child pairs, with children born between April 1, 1991 and December 31, 1992, were included.
Adult participants completed a food frequency questionnaire at 32 weeks gestation. The questionnaire gathered data related to the consumption of 43 food groups and food items, with detailed questions on daily consumption of 8 basic foods such as sugar, coffee, and tea. Total energy intake, daily nutrient intake, and free sugar intake were estimated using questionnaire responses. Similar food frequency questionnaires were used to gather information on child participants’ free sugar consumption beginning at 3 years, and both maternal and paternal sugar consumption 4 years postpartum.
Both the questionnaire data and obstetric records were used to classify women into one of 4 mutually exclusive categories:
- No evidence of glycosuria or diabetes
- Existing diabetes before pregnancy
- Gestational diabetes
- Persistent glycosuria during pregnancy
Women were also divided into 5 quintiles based on daily free sugar intake: 1.6 to 34.0 g/d; 34 to 46.6 g/d; 46.6 to 60.8 g/d, 60.8 to 82.4 g/d; and 82.4 to 345.1 g/d.
Primary study outcomes were physician-diagnosed asthma, wheezing, eczema, hay fever, atopy, total immunoglobulin E (IgE), and lung function in offspring.
The researchers found that 12.2% of children had clinician-diagnosed asthma, 10.7% had wheezing with whistling, 8.8% had hay fever, 16.2% had eczema, and 21.5% had atopy; 61.8% did not have any of these outcomes.
Although women in the highest sugar-intake quintile had lower pre-pregnancy body mass index (BMI), these women gained the most weight during pregnancy and had a higher total energy intake. In a similar manner, offspring of these women were more likely to have weighed less at birth and to have a lower BMI at age 7.
Following adjustment for potential confounders, the researchers found weak evidence for associations between maternal free sugar intake during pregnancy and childhood asthma and wheeze in the highest vs lowest quintile (odds ratio [OR]: 1.31; 95% CI, 0.98-1.75 vs OR: 1.42; 95% CI, 1.05-1.92; per quintile P trend =.09 and .08, respectively). No associations with eczema, hay fever, total IgE, forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), or average forced expiratory flow during mid (25% to 75%) portion of FVC (FEF25-75). A positive association was identified between maternal free sugar intake and atopic asthma (OR: 2.01; 95% CI, 1.23-3.29; per quintile P trend =.004).
The findings were not substantially altered after adjustments for maternal pre-pregnancy BMI, gestational age at delivery, birth weight, weight gain during pregnancy, or offspring BMI at age 7 were performed; additional adjustments for maternal consumption of vitamin E, zinc, and fruits and vegetables during pregnancy did not change the results.
“To the best of our knowledge, these are novel findings,” the researchers wrote. “Our longitudinal findings linking maternal free sugar intake in pregnancy to childhood atopy and atopic asthma extend the ecological results [of a previous study].” 2
“[W]e found no association between maternal diabetes during pregnancy and any outcome in the offspring, although … maternal diabetes was associated with higher birth weight,” they continued.
Dr Bédard and colleagues cited the high levels of sugar consumption in Western countries — and the similarly high prevalence of allergy and asthma — suggesting that the establishment of a causal link could “raise exciting prospects” for primary disease prevention.
“While high fructose consumption has been proposed as a risk factor for obesity, we found no evidence to suggest that the associations between maternal free sugar intake and atopy and atopic asthma in the offspring were mediated by maternal BMI, gestational weight gain, or child’s BMI,” the researchers concluded.
- Bédard A, Northstone K, Henderson AJ, Shaheen SO. Maternal intake of sugar during pregnancy and childhood respiratory and atopic outcomes [published online July 5, 2017]. Eur Respir J. doi:10.1183/13993003.00073-2017
- Thornley S, Stewart A, Marshall R, Jackson R. Per capita sugar consumption is associated with severe childhood asthma: an ecological study of 53 countries. Prim Care Respir J. 2011;20(1):75-78. doi:10.4104/pcrj.2010.00087