Low, high carbohydrate diets in pregnant women raise risk for infant allergic diseases

Key takeaways:

• Infants of pregnant women following low and high carbohydrate diets had an elevated risk for allergic diseases.
• Replacing 5% of energy from carbohydrate for protein or fat in a diet high in carbohydrates led to a lower risk for IgE-mediated allergic diseases.
• Replacing 5% of energy from fat for carbohydrates in a diet low in carbohydrates also reduced risk for IgE-mediated allergic diseases.

A higher risk for allergic diseases in infants correlated with both low carbohydrate-high protein and fat and high carbohydrate-low protein and fat maternal diets, according to a study published in Pediatric Allergy and Immunology.

“To the best of our knowledge, these are novel findings regarding the association of maternal low-carbohydrate diet (LCD) score with infant allergy,” Xi Chen, PhD, of the department of nutrition and food hygiene at Huazhong University of Science and Technology, Tongji Medical College, Wuhan, China, and colleagues wrote. “Epidemiological studies among pregnant women have reported the U-shaped association between maternal LCD score during pregnancy and gestational diabetes mellitus (GDM) risk, and our longitudinal findings linking maternal LCD score during pregnancy to allergic diseases in infants confirmed the long-term effect of diet during pregnancy.”

The prospective cohort study included 1,636 mother-infant pairs from the Tongji Maternal and Child Health Cohort study in China. Researchers sought to observe the relationship between pregnant women’s LCD scores and the risk for allergic diseases in infants up until they turned 2 years old.

Participants answered food frequency questionnaires during late pregnancy, and researchers determined LCD scores— for which higher scores indicated lower consumption of carbohydrates — based on the mother’s percentage of dietary energy intake from carbohydrate, protein and fat. Quintiles were created using LCD scores and intake of macronutrients.

Follow-ups to check for allergic diseases were taken at 3, 6, 12 and 24 months postpartum.

Overall, 230 infants (14.2%) developed IgE-mediated allergic diseases, such as eczema, asthma and allergic rhinitis; 77 (4.7%) had allergic contact dermatitis; and 488 (29.8%) had food allergy.

Results showed an increased risk for IgE-mediated allergic diseases for infants of mothers in both the highest (adjusted RR = 1.72; 95% CI, 1.22-2.63) and lowest (aRR = 1.77; 95% CI, 1.13-2.77) quintiles of overall LCD score compared with the middle quintile.

Researchers also found that, for women consuming a diet high in carbohydrates (LCD score < 15), replacing 5% of energy from carbohydrates with protein (RR = 0.39; 95% CI, 0.24-0.64) or fat (RR = 0.95; 95% CI, 0-0.995) decreased risk for IgE-mediated allergic diseases.

Similarly, a lower risk also was observed when pregnant women following a low-carbohydrate diet (LCD score 15) switched 5% of energy from fat with carbohydrates (RR = 0.77; 95% CI, 0.77-0.78).

“These findings suggest that not only amount but also sources and components of macronutrients display differential associations with health outcomes,” Chen and colleagues wrote. “If further confirmed, dietary guidelines on macronutrient intake should take into account the divergent associations of high-quality carbohydrate, animal protein, and animal fat. This study provided an appropriate strategy for the prevention of allergic diseases in early life and suggested that public health recommendations should focus on the improvement of macronutrient sources.”