Prenatal Omega-3 May Reduce Infant Food Allergies

By Kelsey Costa, MS, RDN on January 1, 2024 — Medically Reviewed by Eliza Whitaker, MS, RDN

Recent research points to the potential of omega-3 supplementation during pregnancy in reducing food allergy risk among offspring.

Photo by Hollie Santos @holliesantos/Unsplash

Summary

• A new study highlights the role of omega-3 during pregnancy in reducing childhood food allergies.

• The study found that maternal omega-3 supplementation during pregnancy and lactation significantly reduces the risk of food sensitization in offspring.

• The role of omega-3 supplementation during childhood was found to be less significant in allergy prevention.

Over the last twenty years, a notable increase in allergic disorders, particularly food allergies and atopic eczema in infants and children, has been observed globally. 

Food allergies (FA), especially IgE-mediated ones, impact nearly 11% of the general population and 8% of children and have been recognized as a rising public health concern. 

Common IgE-mediated allergies include cow’s milk, eggs, soy, wheat, peanuts, tree nuts, fish, and shellfish.

To counter this issue, nutritional interventions during pregnancy are being explored for their potential protective effects on offspring. 

A new meta-analysis looking into omega-3 supplementation and its impact on childhood food allergies has shed new light on the most effective timing of supplementation.

The research shows a significant correlation between maternal intake of omega-3 supplements during pregnancy and lactation and a decreased risk of food allergies in children.

This study was published in June 2023 in The Journal of Allergy and Clinical Immunology.

The science behind omega-3 and food allergies

Omega-3 fatty acids are essential fatty acids that are important for human health. They have anti-inflammatory effects and help to regulate immune responses. 

We are beginning to understand their role in influencing the immune system's response to allergens. 

When consumed by mothers during pregnancy, omega-3 may play a crucial role in preventing food allergies in children. These essential nutrients are known to reduce inflammation and regulate immune responses, possibly by altering an infant's immune system during development. 

The process underlying how maternal omega-3 supplementation during pregnancy impacts the development of FA or sensitization in children is multifaceted. It is proposed that maternal diet during pregnancy and lactation influences the infant's developing immune system. 

For instance, when consumed by mothers during pregnancy, omega-3 polyunsaturated fatty acids (PUFA) support prenatal modulation, preventing inflammation in infants through epigenetic mechanisms. 

This intake also boosts maternal and fetal omega-3 PUFA levels, transferring eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) to the fetus, modulating its immune system and reducing allergy risk. 

Additionally, there are indications that omega-3 supplementation during pregnancy can influence the gut microbiota, improving infant FA. The alteration in gut bacteria due to omega-3 PUFA intake can result in greater anti-inflammatory interleukin 10 production, making individuals more resistant to allergies.

New findings in food allergy prevention 

The study findings reveal a consistent and significant connection between the daily dosage of omega-3 supplementation during pregnancy and reduced egg sensitization in infants, particularly during their early years. 

Each increase in 100 mg/day of omega-3 supplementation was associated with a 3.2% decrease in egg sensitization risk in early infancy.

The research also demonstrated that maternal omega-3 supplementation during pregnancy and lactation was more effective than childhood supplementation in reducing the risk of food allergies, including egg and peanut sensitization.

Some of these protective effects extend beyond the first three years of life.

However, postnatal omega-3 supplementation to the infant did not exhibit the same protective effects.

This dose-dependent relationship between maternal omega-3 supplementation and childhood food allergies suggests that a higher dosage of omega-3 may be more beneficial in allergen sensitization prevention. Still, further research is needed to understand these trends.

Strengths and Limitations 

This systematic review and meta-analysis is strengthened by its systematic approach to identifying relevant publications, focus on randomized controlled trials (RCTs), inclusive review of different omega-3 supplementation interventions, and its novel quantification of the dose effect of early-life omega-3 PUFA exposure on egg sensitization. 

However, potential limitations include:

• reliance on diagnostic methods other than oral food challenge tests, possibly leading to overestimations

• potential residual confounding factors like allergic dermatitis, gut microbiome, and timing of solid food introduction

• language bias limiting the research to English publications

• lack of studies exploring the impact of childhood omega-3 supplementation on food allergies

What expectant parents should know 

The results of the study provide a crucial evidence-based recommendation for expectant mothers, as well as dietary guidelines for pregnant women. 

Maternal omega-3 supplementation during pregnancy and lactation appears to be a promising strategy for preventing food allergies among offspring. 

Omega-3 intake may also play a role in decreasing other atopic disorders, such as atopic dermatitis, asthma, and allergic rhinitis. 

It is worth noting that additional studies are needed to investigate these potential benefits further. 

Parents should consult their registered dietitian or healthcare provider to discuss the safest and most effective way to supplement their diet with omega-3 fatty acids during pregnancy. 

The findings of this study provide encouraging evidence that proper nutrition during pregnancy is essential for the health and well-being of both mother and child. With more research, we may be able to better understand how maternal omega-3 supplementation can help protect against allergic diseases in the long term. 

In addition to increased omega-3 intake, pregnant women should consume a healthy and balanced diet, including plenty of fresh fruits, vegetables, legumes, and whole grains. 

Proper nutrition and food introduction are also key for the health and development of infants and may reduce their risk of developing food allergies later in life. 

Other dietary strategies

Besides supplementation, there are several ways to consume more omega-3 during pregnancy, explains Allyson Brigham, MS, RDN, a registered dietitian at Los Robles Hospital, Thousand Oaks, CA, who was not involved with the study.

Nuts, seeds, and fatty fish are excellent dietary sources of omega-3.

“Try making a trail mix with walnuts, almonds or macadamia nuts, dried fruit, and dark chocolate,” Brigham says.

She also recommends incorporating flax and chia seeds into a daily smoothie. “Add ground flax seed and chia seeds to a berry smoothie with spinach.”

Brigham suggests eating two servings of low-mercury, cold-water fish per week, like salmon. 

In addition to increasing omega-3 intake during pregnancy, Brigham told Dietitian Insights:

“Foods and nutrient consumption during pregnancy has been shown to directly affect the food preferences, aversions, and allergen risk to the fetus. Parents should be aware of the importance of a balanced variety of meals with omega-3 fatty acids during pregnancy. Supplements, including Folic acid supplementation, is also important in ensuring healthy outcomes for both the mother and fetus throughout the gestation period.”

While the present research focused on maternal dietary interventions, Brigham expressed the importance of postnatal strategies in reducing the risk of childhood FA. 

“Introducing top allergen foods, including peanuts early on (around the 6 month period) has shown success in lowering instances of developing allergies later on in life,” she said. “These foods should be offered to children on a regular basis to maintain tolerance and avoid allergies and aversions.”

The bottom line

This meta-analysis provides a new understanding of the role of omega-3s in preventing food allergies among offspring. 

Results suggest intake of omega-3 supplements by mothers during pregnancy and lactation may decrease the likelihood of food allergies in their children, compared to either no intake during pregnancy or the child's intake during childhood.

The findings are an essential contribution to the growing body of work on nutrition for allergy prevention, potentially providing a new tool for expectant mothers in the fight against food allergies. 

However, further research is needed to better understand the benefits of omega-3 supplementation during pregnancy for food allergy prevention in children. 

In addition, parents should discuss their individual needs with their registered dietitian or healthcare provider before taking any supplements. 

Other preventive measures should still be taken to reduce the risk of infant food allergies. 

Note: All information in this article is for educational purposes only and should not be interpreted as medical advice. The reader should consult with a healthcare provider before using any supplements or making any dietary or lifestyle changes. Read the full medical disclaimer.

Dietitian Insights articles are authored by registered dietitians who utilize only high-quality sources, including peer-reviewed studies and reputable agencies, to provide the most up-to-date, evidence-based insights. Read our editorial process to learn more about how our content is medically reviewed and kept current and credible.

• Sources

  Huynh LBP, Nguyen NN, Fan HY, Huang SY, Huang CH, Chen YC. Maternal Omega-3 Supplementation During Pregnancy, but Not Childhood Supplementation, Reduces the Risk of Food Allergy Diseases in Offspring. J Allergy Clin Immunol Pract. 2023;11(9):2862-2871.e8. doi:10.1016/j.jaip.2023.06.005

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Practitioner applications

The science indicates that omega-3 fatty acids, specifically DHA, contribute significantly to the development of infants' brains during pregnancy and early life.

With this knowledge, dietitians and healthcare providers should advocate for at least standard supplementation of omega-3 in expectant mothers' diets. Increased supplementation may offer additional benefits, such as lowered risk of food allergies in offspring. 

While we continue to explore the benefits of higher doses, standard omega-3 supplementation should be a baseline recommendation for all pregnant women to support their babies' cognitive development and overall health.