The body of evidence about nuts and allergies continues to grow, with new local and international research papers regularly published. Here are some of the key papers in nuts and allergy research.

Key studies: Systematic literature reviews and meta-analyses

Oral immunotherapy for peanut allergy (PACE): A systematic review and meta-analysis of efficacy and safety. (Chu et al, 2019).

A recent systematic review and meta-analysis shows that it may increase allergic and anaphylactic reactions, despite inducing desensitisation.

Other evidence

Early introduction is not enough: CSACI statement on the importance of ongoing regular ingestion as a means of food allergy prevention. (Abrams et al, 2023).
Guidelines consistently recommend early allergen ingestion (commonly between 4-6 months of age), for food allergy prevention. This new statement, from the Canadian Society of Allergy and Clinical Immunology, also highlights the importance of frequency of ingestion. It says: ‘Both early introduction and, once introduced, regular ingestion of age-appropriate amounts and textures of all common allergens multiple times per month (with a goal of at least once each week based on expert opinion) are very likely to be useful to establish and maintain tolerance’.

The natural history of peanut and egg allergy in children up to age 6 years in the HealthNuts population-based longitudinal study. (Peters et al, 2022).
This study looked into peanut and egg allergy in children over time, in the HealthNuts cohort (5,276 children recruited at 1 year of age, and followed prospectively). It found that most egg allergy and nearly one-third of peanut allergy resolves naturally by age 6 years. The prevalence of peanut allergy at age 6 years (3.1%) was similar to that at age 1 year, largely due to new-onset peanut allergy after age 1 year. The factors at age 1 year associated with persistence of peanut allergy were peanut skin prick test result of ≥8mm, sensitisation to tree nuts, and early-onset severe eczema.

Early introduction of allergenic foods and the prevention of food allergy. (Trogen et al, 2022).
This paper reinforces that the early introduction of allergenic foods appears to be an effective strategy for minimising the public health burden of food allergy. It states that for children considered high risk of developing food allergy, the consensus is clear that not only should allergenic foods not be delayed, but they should be introduced at approximately 4 to 6 months of age to minimise the risk of food allergy development.

Early food intervention and skin emollients to prevent food allergy in young children (PreventADALL): a factorial, multicentre, cluster-randomised trial. (Skjerven et al, 2022).
This research, involving 2,397 newborn infants, aimed to determine whether early food introduction reduced the risk of food allergy. Prevalence of food allergy at 36 months was reduced in the food intervention group (early complementary feeding of peanut, cow’s milk, wheat, and egg from 3 months of age), compared with the control group (no food intervention group). The researchers say the results support early introduction of common allergenic foods as a safe and effective strategy to prevent food allergy.

Probiotic peanut oral immunotherapy versus oral immunotherapy and placebo in children with peanut allergy in Australia (PPOIT-003): A multicentre, randomised, phase 2b trial. (Loke et al, 2022).
This research showed that treatment with oral immunotherapy, with or without a probiotic, for childhood peanut allergy, can significantly improve quality of life in children, compared with current standard care, which is peanut avoidance. After 18 months of treatment, 46% and 51% of children who received the combination treatment or the oral immunotherapy alone, respectively, were in clinical remission, compared to 5% in the placebo group.

Has the prevalence of peanut allergy changed following earlier introduction of peanut? The EarlyNuts Study. (Soriano et al, 2021).
The Australian-based EarlyNuts study found that peanut allergy has fallen in Australia since children have been introduced to peanuts earlier in life. It notes that Australian infant feeding guidelines changed in 2016 to recommend starting children on peanuts and other allergenic foods earlier (by age 12 months). The research suggests parents have embraced this advice, and the earlier introduction of peanuts has led to a 16% decrease in peanut allergy. Despite this promising data, the researchers note the overall prevalence of peanut allergy is still high.

Prevalence and early-life risk factors for tree nut sensitization and allergy in young adults. (Bager et al, 2021)
This population-based cohort study (the Swedish birth cohort BAMSE) gauged the prevalence of tree nut sensitisation and reported symptoms at age 24 years, and also assessed early-life factors linked with the development of tree nut allergy. In this Swedish cohort, prevalence of tree nut sensitisation was found to be common (21.2%), but usually asymptomatic. Egg allergy, eczema and asthma at pre-school age were linked with future development of tree nut symptoms and storage protein sensitization.

The influence of cultural attitudes to nut exposure on reported nut allergy: A pilot cross sectional study (2020).
Kayale LB. et al.
The development of peanut and almond allergy through tolerance induction could be prevented by frequent and early ingestion of a moderate quantity of nuts during infancy and by maternal ingestion during pregnancy or lactation.

Real-world tree nut consumption in peanut-allergic individuals. (2019).
In summary, the data supports previous work showing that peanut-allergic individuals are commonly sensitized to tree nuts. It highlights important differences between individual tree nuts, challenging the common practice of categorical management recommendations for tree nuts as a whole group rather than by individual tree nut. The authors conclude the potential for safe introduction of tree nuts in peanut-allergic individuals and indicate that peanut-allergic individuals who consume foods with precautionary labelling are most likely to consume tree nuts.

The Australasian Society of Clinical Immunology and Allergy infant feeding for allergy prevention guidelines. (2019).
The guidelines reinforce the importance of introducing peanut and egg in the first year of life. The optimal timing of introducing other allergens (including tree nuts) is not well understood, although it is still recommended not to delay their introduction.

Asian children living in Australia have a different profile of allergy and anaphylaxis than Australian-born children: A State-wide survey. (2018).
Study reveals surprising patterns of allergy/anaphylaxis risk, suggesting that genetics and environment may be an important factor.

Effect of diet and maternal education on allergies among preschool children: a case-control study. (2017).
The consumption of nuts was also associated with a lower 61% risk of eczema among 4-6 years old children. The results indicated a beneficial effect of a frequent consumption of fresh fruit and nuts on the prevalence of allergies among children. These results might have important implications for children’s health.