A recently published Italian systematic review and meta-analysis concluded that food allergies, surprisingly common in older people, can interfere with adequate nutritional intake, and were often overlooked, reports Medscape.
The systematic review and meta-analysis was published in the World Allergy Organisation Journal.
With the global rise in food allergies, research has largely focused on younger groups, yet older adults have distinct risk factors such as immunosenescence, chronic inflammation, micronutrient deficiencies, multimorbidity, and polypharmacy, which could influence allergic responses, wrote study investigators led by Domenico Azzolino, PhD, nutritional scientist in the Geriatric Unit of the Ospedale Maggiore Policlinico in Milan, Italy.
In fact, food-induced anaphylaxis has been reported to account for 6% of emergency department visits and 4.1% of hospitalisations among Americans aged 65 or older.
Because food allergies reflect a loss of tolerance to specific food proteins, their management relies primarily on allergen avoidance.
“Inadequate consumption of protein-rich foods like meat, milk, eggs, and fish is common in older adults and, when compounded by allergen avoidance, may create a vicious cycle of further protein restriction and increased risk of under-nutrition and functional decline,” Azzolino and colleagues wrote.
Global review
With data on food allergies in this age group very sparse, the researchers examined prevalence in 16 studies published from 2004 to 2023 conducted in Europe, North and South America, the Middle East, and Asia. Most were graded as having a moderate risk for bias.
The pooled prevalence of self-reported food allergies was 12% (95% CI, 9%-15%). Self-reported physician-diagnosed food allergies had a prevalence of 7% (95% CI, 5%-8%). Specific immunoglobulin E (sIgE) sensitisation indicated a prevalence of 14% (95% CI, 10%-18%), with sIgE sensitisation to common allergens at 3% for cow’s milk and peanut, 2% for egg, and 1% for soy.
Exploratory comparisons tentatively suggested similar combined prevalence estimates across low- and middle-income countries (10%) and high-income countries (9%).
The prevalence of any type of food allergy varied by setting, country, and assessment method, with a range from 1% to 25%.
The prevalence of clinically confirmed food allergy remains poorly defined, the authors cautioned. “The limited evidence and heterogeneity across studies highlight the need for standardised diagnostic criteria and greater inclusion of older adults in future food allergy research.”
The investigators also called for physicians and older people to avoid normalising food allergy symptoms as part of the ageing process. The identification of food allergies in this group should be part of routine clinical practice to avoid both anaphylactic reactions and adverse consequences for nutritional status, said Azzolino and associates.
Offering a US perspective, David Corry, MD, professor of immunology, allergy, and rheumatology at Baylor College of Medicine in Houston, said he and his colleagues are seeing more consultations for food allergies among adults of all ages now at the Michael E. DeBakey VA Medical Centre compared with 10 or 15 years ago when these consultations were rare.
“My experience is that food allergies are quite uncommon in the over-60 age group but still markedly higher now,” said Corry, who was not involved in the meta-analysis.
He believed front-line physicians were not usually sufficiently aware of the need to identify food allergies. “Some do screen adequately for this, but most do not.”
Corry cautioned that the findings remain uncertain because high-quality confirmatory data on the existence of food allergies were lacking in most of the papers available to the research team.
Ruchi Gupta, MD, MPH, professor of paediatrics and medicine and director of the Centre for Food Allergy & Asthma Research at Northwestern Feinberg School of Medicine in Chicago, offered another US viewpoint on the study but was not involved in the research.
She said food allergies are a lifelong burden, not just a paediatric condition, and de novo adult-onset food allergies are well documented.
“Half of adults reporting convincing allergies report developing a new allergy as an adult,” she told Medscape Medical News.
The progressive remodelling of the older immune system can result in secondary sensitisation, she explained. “The most common form of adult-onset food allergy is pollen-food allergy syndrome, or oral allergy syndrome, driven by cross-reactivity between environmental pollens and structurally similar plant food proteins.”
Age-related delayed gastric emptying and the widespread use of proton pump inhibitors can also impair proper protein digestion. “This allows intact, conformationally stable food proteins to pass through the intestinal mucosa, potentially eliciting new IgE production. We are also learning more about how environmental and microbiome changes impact the immune system,” she added.
Her centre is investigating how ageing affects the immune system’s tolerance to food, because older cohorts represent one of the fastest-growing yet least-understood demographics in allergy research. Under development is a validated tool for assessing food allergy to help align the prevalence numbers across the globe.
In her view, best practice should rely on targeted, proactive clinical history-taking. “If a patient describes symptoms consistently correlating with specific food ingestion, a careful, customised diagnostic workup should be initiated.”
If an allergy is confirmed and an elimination diet is required, she said, an immediate referral to a dietician is essential to ensure adequate protein and micronutrient intake to prevent frailty.
Study details
Prevalence of food allergies in older adults: A systematic review and meta-analysis
Domenico Azzolino, Ivan Baldassari, Simone Perna, et al.
Published in World Allergy Organisation Journal in August 2026
Abstract
Introduction
Food allergies (FAs) are rising worldwide, but research has mainly focused on younger groups. Older adults may have distinct risk factors (eg, immunosenescence, chronic inflammation, micronutrient deficiencies, multimorbidity, and polypharmacy) that could influence allergic responses. This review aimed to assess FAs prevalence in older adults.
Methods
Following PRISMA guidelines, a systematic search across PubMed/Medline, Scopus, Embase, and Web of Science identified studies published up to December 2024. The review planning phase began in July 2023 and included protocol drafting and methodological discussions. No study screening, data extraction, or data analysis was conducted prior to PROSPERO submission and registration (CRD42023445399). Studies reporting FAs prevalence in older adults by all available methods were included. Self-reported and sensitisation-based estimates reflect potential FAs, whereas challenge-confirmed FAs represent clinically confirmed allergy. The risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist. Data were pooled using random-effects meta-analyses.
Results
Sixteen studies, involving 33,165 older adults from 11 countries, were included qualitatively, and fourteen were included quantitatively. Most studies were graded as having a moderate risk of bias. The pooled prevalence of self-reported FAs was 12% (95% CI 9–15). Self-reported physician-diagnosed FAs showed a prevalence of 7% (95% CI 5–8). Specific IgE (sIgE) sensitization indicated a prevalence of 14% (95% CI 10–18). Only 1 study reported challenge-confirmed FAs with a prevalence of 0.5%. Exploratory comparisons suggest similar combined prevalence estimates across low- and middle-income countries (LMIC) (10%) and high-income countries (9%), though the small number of LMIC studies and differences in assessment methods preclude firm conclusions. sIgE sensitisation to common allergens was 3% for cow's milk and peanut, 2% for egg and 1% for soy.
Conclusion
Older adults show meaningful rates of self-reported food-related symptoms and sensitisation. However, the prevalence of clinically confirmed FAs remains poorly defined. The limited evidence and heterogeneity across studies highlight the need for standardised diagnostic criteria and greater inclusion of older adults in future FAs research.
Medscape article – Food Allergies in Older Adults: An Overlooked Threat (Open access)
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