Maternal diet during pregnancy may impact development of asthma, allergies in offspring

A maternal diet with plenty of vegetables and limited fried, low-fiber and sugary foods may prevent asthma and allergies in offspring, according to a speaker at the American Academy of Allergy, Asthma & Immunology Annual Meeting.

Carina Venter, PhD, RD, associate professor of pediatrics in the section of allergy/immunology at Children’s Hospital Colorado and University of Colorado Denver School of Medicine, provided the latest data on the role the maternal diet during pregnancy may have on the infant microbiome and subsequent development of allergies and asthma, including research she has led on the topic.

Currently, it is recommended that a prenatal supplement with vitamin D be taken to reduce the risk for asthma and wheeze in offspring, Venter told Healio. Also, all allergy and pediatric medical societies recommend against avoiding food allergens during pregnancy to prevent food allergies in offspring, Venter said, although she added that the impact of maternal diet on other allergic diseases has so far been less conclusive.

Carina Venter

In a study published last year in Allergy, Venter and colleagues developed a maternal diet index during pregnancy — which included weighted measures of increased intake of vegetables and yogurt, and reduced intake of fried potatoes, rice/grains, red meats, pure fruit juice and cold cereals — to better assess the impact of maternal diet on offspring allergy outcomes.

Overall, greater intake of vegetables and yogurt appeared protective against development of offspring allergic disease, whereas the other food items were associated with greater risk in offspring.

Using these findings to inform the maternal diet index, researchers found that a one-unit increase in the index significantly reduced the likelihood of offspring allergic rhinitis (OR = 0.82; 95% CI, 0.72-0.94), atopic dermatitis (OR = 0.77; 95% CI, 0.69-0.86), asthma (OR = 0.84; 95% CI, 0.74-0.96) and wheeze (OR = 0.8; 95% CI, 0.71-0.9), but not food allergy (0.84; 85% CI, 0.66-1.08).

The researchers called their study the first to show a relationship between a maternal diet index and prevention of multiple allergic diseases in offspring but cautioned that more research is needed.

“Our data show that a diet with increased intake of vegetables and reduced intake of fried, low fiber and sugary foods is associated with reduced asthma, wheeze, allergic rhinitis and eczema by 4 years, and all allergies by 2 years of age,” Venter told Healio. “This needs to be confirmed in other cohorts and in randomized controlled trials.”

The researchers acknowledged that many of the foods in the index are known to impact the diversity and function of the gut microbiome, but how that affects the offspring microbiome, which in turn affects their allergy risk, remains to be elucidated.

“We have some preliminary data on how the maternal diet may affect the child’s microbiome and epigenetic profile, but many more studies are needed,” Venter said.

Despite these unknowns, maternal diet “is likely to play a role,” she added.

“Recent data indicate that the maternal diet can manipulate the maternal microbiome and subsequently the infant microbiome, but the exact effect in relation to allergy is still unclear,” she said.

Specifically, a study by Selma-Royo and colleagues, published in 2020 in European Journal of Nutrition, showed that maternal intake of saturated fats and monosaturated fatty acids appeared linked to intestinal markers and therefore likely indicates microbial transmission to the neonate.

Despite these data, a generalized diet that mothers can assume to reduce their offspring risk remains elusive.

It is clear that a diet filled with a variety of allergens in the infant’s first year of life has been shown to reduce their risk for later development of food allergies.

But pairing individual pregnant mothers with their optimal dietary intervention to prevent offspring allergic diseases remains a lofty goal.

“This statement is a ‘blue sky’ view of where we would like to be in the future, but more research data are required and we are not anywhere near clinical implementation yet,” Venter told Healio.

References:

• Selma-Royo M, et al. Eur J Nutr. 2020;doi:10.1007/s00394-020-02337-7.
• Venter C, et al. Allergy. 2021;doi:10.1111/all.14949.