NIHR Signal Infant diets that include egg or peanut products appear to reduce food allergies

Published on 29 November 2016

Certain allergenic foods introduced to an infant’s diet while weaning appear to reduce the chance of developing food allergies. This high quality review, including studies published this year, suggests that historical recommendations to delay the introduction of peanut and other allergenic foods to infant child’s diet in the first year of life may have been mistaken.

The methodological limitations in some studies included in this review, reduce our certainty in the degree of benefit, but as more high quality studies are undertaken the benefits and practicalities of how to introduce these foods are likely to become clearer.

The causes of food allergies are not fully understood and the number of people with food allergies and coeliac disease is rising in the UK. Current NHS advice is that potentially allergenic foods can be introduced one-by-one during weaning to check for any allergic reaction, but advice is under review.

A previous trial in high-risk infants without peanut allergy, included in this review, confirms that regularly eating peanuts from an early age can prevent peanut allergy.

Infant diets that include egg or peanut products appear to reduce food allergies

Why was this study needed?

Around 10 people a year die from allergic reactions to foods in the UK. Although not everyone has such serious and dangerous reactions, many people live with the daily stress of managing their food allergies and any reactions they suffer.

Coeliac disease is not an allergy, but is caused by the body identifying gluten in wheat as a threat and attacking it. It causes diarrhoea, pain and discomfort, which can be severe, and affects around 1 in 100 people in the UK.

The number of people with food allergies and coeliac disease is rising – around 6-8% of children have a food allergy – and no-one is exactly sure why. For example, there has been a lot of debate about when to introduce potentially allergenic foods into children’s diets.

This systematic review looked at a range of foods and sought evidence on the link between the introduction of potentially allergenic foods and development of food allergies or coeliac disease.

What did this study do?

This systematic review and meta-analysis included randomised controlled trials and observational studies (such as cohort studies). It investigated whether the timing of introducing potentially allergenic foods affected the likelihood of children developing food allergies or coeliac disease.

For allergies there were 24 intervention studies (13,298 participants) and 69 observational studies (142,103 participants). For coeliac disease there were five intervention studies (5,623 participants) and 48 observational studies (63,576 participants). 26 of the included studies were UK-based.

Most of the included studies did not have a serious risk of bias. There was concern about the number of people dropping out and why that was happening, and how potential confounding factors from observational studies were accounted for in data analysis. There was a serious risk of bias amongst studies looking at eczema and wheeze related to introducing cow’s milk. These risks of bias affect our confidence in the findings for these foods.

What did it find?

  • Introducing egg from four to six months was associated with a reduced likelihood of developing egg allergy than later on (risk ratio [RR] 0.56, 95% confidence interval 0.36 to 0.87, 5 trials including 1,915 participants). This could mean 24 fewer people with egg allergy per 1,000 population (assuming that 54 in 1,000 people have this allergy).
  • Early peanut introduction from four to 11 months was associated with a reduced chance of developing peanut allergy (RR 0.29, 95% CI 0.11 to 0.74, 2 studies including 1,550 participants). This could lead to 18 fewer cases of peanut allergy per 1,000 population (assuming that 25 in 1,000 people have this allergy).
  • Introducing milk early was not associated a milk allergy (RR 0.76, 95% CI 0.32 to 1.78, 2 studies including 1,550 participants).
  • The timing of gluten introduction was not associated with the risk of developing coeliac disease (RR 1.22, 95% CI 0.81 to 1.83, 4 studies including 1,822 participants).

What does current guidance say on this issue?

2008 NICE guidelines recommend that babies are breast-fed or given infant formula for the first six months of their lives. When introducing solid foods, advice on the NHS Choices website suggests that foods babies could be allergic to – such as those containing cows' milk, eggs, wheat, gluten, nuts, peanuts, peanut products, seeds, fish and shellfish – should be introduced in small quantities and one at a time to check for allergy.

People with a family history of eczema, asthma or hay fever are advised to speak to their GP or health visitor before introducing peanuts and peanut products.

What are the implications?

This systematic review was undertaken as part of a wider programme of work to inform UK infant feeding guidance that the Food Standards Agency will produce.

Though these findings broadly support current NHS advice that potentially allergenic foods do not need to be avoided, the new benefits of the introduction of these foods have not yet been fully considered in advice and guidance.

The studies included in this review had some limitations which mean that a broad consideration of a number of other sources of evidence will be required before recommendations to change of practice are made.

Citation and Funding

Ierodiakonou D, Garcia-Larsen V, Logan A, et al. Timing of Allergenic Food Introduction to the Infant Diet and Risk of Allergic or Autoimmune Disease: A Systematic Review and Meta-analysis. JAMA. 2016;316(11):1181-1192.

This work was funded by the UK Food Standards Agency and supported by the National Institute for Health Research Imperial Biomedical Research Centre and the MRC-Asthma UK Centre in Allergic Mechanisms of Asthma. Dr Trivella was supported by Cancer Research UK.

Bibliography

Allergy UK. Why is Allergy Increasing? Sidcup: Allergy UK; 2015.

Du Toit G, Roberts G, Sayre P, et al. Randomized trial of peanut consumption in infants at risk for peanut allergy. New Engl J Med. 2015;372(9):803-13.

FSA. Allergy and intolerance. London: Food standards agency.

FSA. Food allergy facts. London: Food standards agency.

FSA. Systematic review of scientific published literature on infant feeding and development of atopic and autoimmune disease. London: Food standards agency; 2013.

NHS Choices. Coeliac disease. London: Department of Health; 2014.

NHS Choices. Your baby's first solid foods. London: Department of Health; 2015.

NICE. Atopic eczema in under 12s: diagnosis and management. CG57. London: National Institute for Health and Care Excellence; 2007.

NICE. Maternal and child nutrition. PH11. London: National Institute for Health and Care Excellence; 2014.

Why was this study needed?

Around 10 people a year die from allergic reactions to foods in the UK. Although not everyone has such serious and dangerous reactions, many people live with the daily stress of managing their food allergies and any reactions they suffer.

Coeliac disease is not an allergy, but is caused by the body identifying gluten in wheat as a threat and attacking it. It causes diarrhoea, pain and discomfort, which can be severe, and affects around 1 in 100 people in the UK.

The number of people with food allergies and coeliac disease is rising – around 6-8% of children have a food allergy – and no-one is exactly sure why. For example, there has been a lot of debate about when to introduce potentially allergenic foods into children’s diets.

This systematic review looked at a range of foods and sought evidence on the link between the introduction of potentially allergenic foods and development of food allergies or coeliac disease.

What did this study do?

This systematic review and meta-analysis included randomised controlled trials and observational studies (such as cohort studies). It investigated whether the timing of introducing potentially allergenic foods affected the likelihood of children developing food allergies or coeliac disease.

For allergies there were 24 intervention studies (13,298 participants) and 69 observational studies (142,103 participants). For coeliac disease there were five intervention studies (5,623 participants) and 48 observational studies (63,576 participants). 26 of the included studies were UK-based.

Most of the included studies did not have a serious risk of bias. There was concern about the number of people dropping out and why that was happening, and how potential confounding factors from observational studies were accounted for in data analysis. There was a serious risk of bias amongst studies looking at eczema and wheeze related to introducing cow’s milk. These risks of bias affect our confidence in the findings for these foods.

What did it find?

  • Introducing egg from four to six months was associated with a reduced likelihood of developing egg allergy than later on (risk ratio [RR] 0.56, 95% confidence interval 0.36 to 0.87, 5 trials including 1,915 participants). This could mean 24 fewer people with egg allergy per 1,000 population (assuming that 54 in 1,000 people have this allergy).
  • Early peanut introduction from four to 11 months was associated with a reduced chance of developing peanut allergy (RR 0.29, 95% CI 0.11 to 0.74, 2 studies including 1,550 participants). This could lead to 18 fewer cases of peanut allergy per 1,000 population (assuming that 25 in 1,000 people have this allergy).
  • Introducing milk early was not associated a milk allergy (RR 0.76, 95% CI 0.32 to 1.78, 2 studies including 1,550 participants).
  • The timing of gluten introduction was not associated with the risk of developing coeliac disease (RR 1.22, 95% CI 0.81 to 1.83, 4 studies including 1,822 participants).

What does current guidance say on this issue?

2008 NICE guidelines recommend that babies are breast-fed or given infant formula for the first six months of their lives. When introducing solid foods, advice on the NHS Choices website suggests that foods babies could be allergic to – such as those containing cows' milk, eggs, wheat, gluten, nuts, peanuts, peanut products, seeds, fish and shellfish – should be introduced in small quantities and one at a time to check for allergy.

People with a family history of eczema, asthma or hay fever are advised to speak to their GP or health visitor before introducing peanuts and peanut products.

What are the implications?

This systematic review was undertaken as part of a wider programme of work to inform UK infant feeding guidance that the Food Standards Agency will produce.

Though these findings broadly support current NHS advice that potentially allergenic foods do not need to be avoided, the new benefits of the introduction of these foods have not yet been fully considered in advice and guidance.

The studies included in this review had some limitations which mean that a broad consideration of a number of other sources of evidence will be required before recommendations to change of practice are made.

Citation and Funding

Ierodiakonou D, Garcia-Larsen V, Logan A, et al. Timing of Allergenic Food Introduction to the Infant Diet and Risk of Allergic or Autoimmune Disease: A Systematic Review and Meta-analysis. JAMA. 2016;316(11):1181-1192.

This work was funded by the UK Food Standards Agency and supported by the National Institute for Health Research Imperial Biomedical Research Centre and the MRC-Asthma UK Centre in Allergic Mechanisms of Asthma. Dr Trivella was supported by Cancer Research UK.

Bibliography

Allergy UK. Why is Allergy Increasing? Sidcup: Allergy UK; 2015.

Du Toit G, Roberts G, Sayre P, et al. Randomized trial of peanut consumption in infants at risk for peanut allergy. New Engl J Med. 2015;372(9):803-13.

FSA. Allergy and intolerance. London: Food standards agency.

FSA. Food allergy facts. London: Food standards agency.

FSA. Systematic review of scientific published literature on infant feeding and development of atopic and autoimmune disease. London: Food standards agency; 2013.

NHS Choices. Coeliac disease. London: Department of Health; 2014.

NHS Choices. Your baby's first solid foods. London: Department of Health; 2015.

NICE. Atopic eczema in under 12s: diagnosis and management. CG57. London: National Institute for Health and Care Excellence; 2007.

NICE. Maternal and child nutrition. PH11. London: National Institute for Health and Care Excellence; 2014.

Timing of Allergenic Food Introduction to the Infant Diet and Risk of Allergic or Autoimmune Disease: A Systematic Review and Meta-analysis

Published on 20 September 2016

D Ierodiakonou, V Garcia-Larsen, A Logan, A Groome, S Cunha, J Chivinge, Z Robinson, N Geoghegan, K Jarrold, T Reeves, N Tagiyeva-Milne, U Nurmatov, M Trivella, J Leonardi-Bee, R Boyle

JAMA , 2016

Importance Timing of introduction of allergenic foods to the infant diet may influence the risk of allergic or autoimmune disease, but the evidence for this has not been comprehensively synthesized. Objective To systematically review and meta-analyze evidence that timing of allergenic food introduction during infancy influences risk of allergic or autoimmune disease. Data Sources MEDLINE, EMBASE, Web of Science, CENTRAL, and LILACS databases were searched between January 1946 and March 2016. Study Selection Intervention trials and observational studies that evaluated timing of allergenic food introduction during the first year of life and reported allergic or autoimmune disease or allergic sensitization were included. Data Extraction and Synthesis Data were extracted in duplicate and synthesized for meta-analysis using generic inverse variance or Mantel-Haenszel methods with a random-effects model. GRADE was used to assess the certainty of evidence. Main Outcomes and Measures Wheeze, eczema, allergic rhinitis, food allergy, allergic sensitization, type 1 diabetes mellitus, celiac disease, inflammatory bowel disease, autoimmune thyroid disease, and juvenile rheumatoid arthritis. Results Of 16 289 original titles screened, data were extracted from 204 titles reporting 146 studies. There was moderate-certainty evidence from 5 trials (1915 participants) that early egg introduction at 4 to 6 months was associated with reduced egg allergy (risk ratio [RR], 0.56; 95% CI, 0.36-0.87; I2 = 36%; P = .009). Absolute risk reduction for a population with 5.4% incidence of egg allergy was 24 cases (95% CI, 7-35 cases) per 1000 population. There was moderate-certainty evidence from 2 trials (1550 participants) that early peanut introduction at 4 to 11 months was associated with reduced peanut allergy (RR, 0.29; 95% CI, 0.11-0.74; I2 = 66%; P = .009). Absolute risk reduction for a population with 2.5% incidence of peanut allergy was 18 cases (95% CI, 6-22 cases) per 1000 population. Certainty of evidence was downgraded because of imprecision of effect estimates and indirectness of the populations and interventions studied. Timing of egg or peanut introduction was not associated with risk of allergy to other foods. There was low- to very low-certainty evidence that early fish introduction was associated with reduced allergic sensitization and rhinitis. There was high-certainty evidence that timing of gluten introduction was not associated with celiac disease risk, and timing of allergenic food introduction was not associated with other outcomes. Conclusions and Relevance In this systematic review, early egg or peanut introduction to the infant diet was associated with lower risk of developing egg or peanut allergy. These findings must be considered in the context of limitations in the primary studies.

Expert commentary

The prevalence of food allergy has been rising for many years and it has long been suspected that the timing of introduction of solid foods into the infant diet has a significant impact on the risk of food allergy developing.

This meta-analysis looks at the available high quality evidence and concludes that early introduction of egg and peanut into the infant diet appears to have an important preventative effect for egg and peanut allergy respectively. This builds on recent high quality RCTs and provides a level of evidence that can inform changes to public health advice for allergy prevention.

Dr Adam T Fox, Clinical Director, Specialist Ambulatory Services Directorate, Guy's & St Thomas' Hospitals NHS Foundation Trust

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  •   Allergies, Child Health