Food Allergens in India: Evidence, Regulation, and the State of Current Knowledge
A review of clinical literature, regulatory frameworks, and the boundaries of what is currently known
Food allergy prevalence in India is among the lowest documented in the Asia-Pacific: 0.14% in children and 1.2% in adults, from the largest systematic study conducted on Indian soil. The same study found IgE sensitisation in 19.1% of the children tested — a 136-fold gap between immune sensitisation and clinical allergy.
That gap runs through the Indian food allergy literature consistently, across foods, across study types, across populations. This review documents what the evidence shows and the conditions that made it the shape it is.
Three domains are examined: the clinical and epidemiological literature, the molecular characterisation of India-specific allergens, and the FSSAI mandatory allergen declaration framework. Each domain is reviewed against its own evidentiary standard. Where the literature and the regulation converge, that convergence is noted. Where they do not, the reasons are examined. The review closes with an extended allergen recognition list for Indian food systems — seventeen foods across two evidence tiers, and three foods the current data cannot place.
1 1. What an allergen is
The immune system is a classification system. It encounters proteins, assesses them, and files them — safe or hostile. For most people, most of the time, the filing is accurate.
In some people, an ordinary food protein gets filed as hostile.1 The protein itself is unchanged — digestible, stable, present in millions of meals daily. But the immune system has produced IgE antibodies against it, and every subsequent encounter triggers a response: urticaria, angioedema, anaphylaxis.2 The classification is the allergy.
1 The immune system producing IgE antibodies to a food protein is called sensitisation. Sensitisation is not the same as allergy — many people carry these antibodies without ever having a reaction. What converts sensitisation into clinical allergy is not fully understood.
2 Urticaria is hives. Angioedema is swelling, typically of the lips, tongue, or throat. Anaphylaxis is a systemic reaction — blood pressure drops, airways narrow — that can be fatal within minutes without treatment.
3 Pepsin, the main digestive enzyme in the stomach, breaks most proteins into fragments too small for the immune system to recognise. Proteins that resist this — pepsin-stable proteins — arrive in the gut intact, where immune cells encounter them directly.
4 Cross-reactivity is why someone allergic to one tree nut may react to others, or why sensitisation to a grass pollen can produce symptoms on eating certain fruits. The immune system is recognising a shared structural pattern, not the specific food.
Proteins that survive gastric digestion intact reach the immune system in a form it can respond to.3 Proteins that are heat-stable remain recognisable after cooking. Proteins that share structural features across species mean that sensitisation to one food may produce reactivity to others never directly encountered — a phenomenon called cross-reactivity.4
Which proteins a population’s immune systems tend to misfile varies by geography, diet, and a set of environmental factors that are still being characterised. In the United States, peanut allergy affects roughly 1–2% of the population. In a large systematic study of Indian children, peanut sensitisation was 6.3% by serum-specific IgE. Probable clinical peanut allergy in the same cohort was approximately 0.03%.5
5 Serum-specific IgE measures IgE antibodies to a particular food protein in a blood sample. A positive result means the immune system has been exposed to that protein and produced antibodies — it does not mean the person will react if they eat the food. “Probable food allergy” in the EuroPrevall study required both a positive IgE or skin test and reported symptoms within two hours of eating the food. Neither is the same as a confirmed challenge test.
That gap — between a population that carries the antibodies and a population that develops the disease — runs through the Indian food allergy literature consistently. The sections that follow document what produced it, what it means, and where the evidence currently stands.
2 2. How food allergy is measured
2.1 2.1 The diagnostic hierarchy
Four methods appear in the Indian literature reviewed here, each measuring something different.
Skin prick test (SPT) introduces a small amount of allergen extract into the skin surface; a raised wheal above a defined threshold indicates sensitisation.6 SPT is fast and inexpensive. In the Indian context, the absence of standardised local allergen extracts limits its comparability across studies — most Indian studies use commercial extracts developed for other populations, or in-house preparations with variable protein content (Krishna et al. 2020).
6 A wheal is a raised, itchy bump at the test site, like a small insect bite. The standard threshold is 3mm or more above the negative control. Bigger wheals suggest stronger sensitisation — but again, sensitisation is not allergy.
Serum-specific IgE (sIgE) measures circulating IgE antibodies to a specific food protein via blood test. It has the same diagnostic limitation as SPT: a positive result indicates sensitisation, not confirmed clinical allergy.
Oral food challenge (OFC) requires the patient to eat the food under clinical observation, with symptoms recorded. It is the closest available proxy to real-world exposure, but resource-intensive and not widely available outside specialist centres.7
7 An oral food challenge typically happens in a clinical setting over several hours — the patient eats increasing amounts of the food at intervals while a clinician monitors for reactions. Because reactions can be severe, emergency treatment needs to be immediately available. This is why the absence of adrenaline auto-injectors in India until recently made challenges structurally difficult to conduct safely.
Double-blind placebo-controlled food challenge (DBPCFC) is the diagnostic gold standard: both patient and clinician are blinded to whether the test substance or a placebo is being administered. Highest confidence, used almost exclusively in specialist centres and research protocols.
2.2 2.2 Why these tests give different numbers
A single population, tested by different methods, will produce different numbers. In the EuroPrevall-INCO study — 5,677 children aged 7–10 years across schools in Mysore and Bengaluru — sIgE detected sensitisation in 19.1% of children while SPT detected sensitisation in 4.48% of the same children (Mahesh et al. 2023).8
8 The EuroPrevall-INCO study is the largest systematic food allergy dataset from India. It tested children from schools, not clinics — which means it captures a cross-section of the child population rather than children who had already presented with suspected allergies. This makes its prevalence figures more representative of the general population than most other Indian studies.
9 This matters because the 0.14% figure is the one most often cited as India’s food allergy prevalence. It is the best available estimate from the best available study — but it is not a confirmed allergy rate. A confirmed rate from DBPCFC data would likely be lower. How much lower is not known, because the challenge data does not exist at population scale.
Neither figure represents confirmed food allergy. The “probable food allergy” figure from the same study — 0.14% for Indian children — used a specific operational definition: reported symptoms within two hours of eating a food, combined with a positive sIgE or SPT to that food (Mahesh et al. 2023; Leung et al. 2024). This is not OFC-confirmed. It is a structured symptom-report combined with immunological evidence, which consistently overestimates confirmed allergy relative to DBPCFC.9
DBPCFC-confirmed allergy exists for only three foods in the India-specific data available: rice (6 of 16 patients tested confirmed, Delhi tertiary referral centre), black gram (4 of 14 confirmed, same centre), and chickpea (31 of 41 SPT-positive patients confirmed on challenge, Bombay allergy clinic) (Mahesh et al. 2023; Krishna et al. 2020).10
10 These are small numbers from single centres. A confirmed rate of 6 out of 16 for rice means six people in one Delhi clinic reacted to rice under controlled conditions — it does not mean 37.5% of Indians with rice sensitisation have clinical rice allergy. The value of this data is that it exists at all, not that it is generalisable.
2.3 2.3 What this means for reading the numbers in this review
The figures that appear most frequently in Indian food allergy literature are sensitisation rates and probable food allergy estimates, not confirmed allergy rates. When numbers are cited in §3, the method used to generate them is stated each time. Sensitisation rates are not treated as equivalent to clinical allergy rates; the 136-fold gap in the EuroPrevall India data is the clearest signal that this distinction matters.
3 3. Food allergens in India: what the literature documents
3.1 3.1 The EuroPrevall-INCO study
The EuroPrevall-INCO study enrolled 5,677 children aged 7–10 years across schools in Mysore and Bengaluru and tested each child against a 25-food panel (Mahesh et al. 2023).
Sensitisation rates by sIgE in children: shrimp 10.5%, sesame 8.0%, wheat 6.7%, peanut 6.3%. SPT sensitisation was lower overall — 4.48% aggregate versus 19.1% by sIgE — with jackfruit (2.46%) and cow’s milk (1.35%) leading by SPT (Mahesh et al. 2023).11
11 The difference between sIgE and SPT results for the same foods in the same children reflects the different things each test measures, and the different thresholds each uses to call a result positive. Neither is wrong — they are measuring different aspects of the same immune response.
Probable food allergy in children was 0.14% overall. The leading foods in the probable food allergy subset were cow’s milk (0.5% of that subset) and apple (0.5%), with egg at 0.05% and eggplant at 0.04% (Mahesh et al. 2023).
For adults across two Karnataka cities the picture shifts: 26.5% sensitisation and 1.2% probable food allergy, with legumes, prawn, eggplant, milk, and egg as the leading allergens (Mahesh et al. 2023).12
12 The adult figures being higher than the child figures is consistent with cumulative exposure over time — more years of eating means more opportunity for sensitisation to develop. Whether this reflects a genuine increase in allergy with age or a cohort effect — older adults having grown up under different dietary and environmental conditions — is not established in the available data.
Both study sites are urban Karnataka. The EuroPrevall-INCO data does not cover North India, Northeast India, rural populations, or coastal communities (Leung et al. 2024).
3.2 3.2 Clinic and community studies
Beyond EuroPrevall, (Krishna et al. 2020) compiles 13 individual Indian allergy studies conducted between 2001 and 2019, covering Bombay, Delhi, Mysore, Bengaluru, Lucknow, and Kolkata. These are largely clinic-based cohorts — patients presenting to allergy clinics rather than general population samples.13 Sensitisation rates from these studies are higher than in population-based studies and are not representative of background prevalence in the general population.
13 Think of it this way: if you want to know how common headaches are in a city, surveying people in a neurology clinic will give you a much higher number than surveying people on the street. Both numbers are real — they are just answering different questions. Clinic-based studies tell you what allergens appear in people who have already sought care for a suspected reaction, not how common those allergens are in the population at large.
The table below summarises key findings from those studies alongside FSSAI mandatory status for each allergen.
| Allergen | Sensitisation range | Method | DBPCFC/OFC data | In FSSAI 2020? |
|---|---|---|---|---|
| Black gram (Vigna mungo) | 5.9–10.1% | SPT, sIgE | 4/14 DBPCFC confirmed | No |
| Rice (Oryza sativa) | 6.2–12.1% | SPT, sIgE | 6/16 DBPCFC confirmed | No |
| Lentil (Lens culinaris) | 5.5–9.7% | SPT (N=216–1,860) | None available | No |
| Prawn | 10.3–53.5% | SPT, sIgE | — | Yes (crustaceans) |
| Eggplant (Solanum melongena) | 4.3–9.2% SPT; 0.8% sIgE community | SPT; sIgE | None available | No |
| Egg | 6.9–34.9% | SPT, sIgE | — | Yes |
| Banana | 3.6–40.6% | SPT | None available | No |
| Wheat | 6.7–11.93% | SPT, sIgE | — | Yes (gluten cereals) |
| Chickpea (Cicer arietinum) | SPT positive 41/1,400 | SPT (N=1,400 clinic) | 31/41 DBPCFC confirmed | No |
| Red gram / pigeon pea (Cajanus cajan) | 12.6% | sIgE (Karnataka N=2,219) | None available | No |
| Green gram (Vigna radiata) | 12.5% | sIgE (Karnataka N=2,219) | None available | No |
Note on eggplant: stored eggplant accumulates histamine at levels that can produce false-positive SPT results. Sensitisation figures for eggplant based on SPT should be interpreted with this confound in mind (Bhattacharya et al. 2018). 14
14 Histamine is the same compound the body releases during an allergic reaction — which is why antihistamines treat allergy symptoms. When stored eggplant already contains elevated histamine, introducing it into a skin prick test can trigger a wheal response that looks like sensitisation but is actually a direct chemical reaction to the histamine, not an IgE-mediated immune response. The SPT result is positive; the underlying mechanism is different.
15 Urban children consistently showing higher sensitisation than rural children from the same region — same genetic background, different environment — is one of the signals researchers use to argue that environment, not genetics, drives much of the variation in food allergy rates. What specifically differs between urban and rural environments in ways that affect allergy development is an open question.
An urban–rural gradient is visible in the available data. In Karnataka schools, sensitisation to prawn was 17.7% urban versus 5.7% rural; peanut 19.6% versus 10.4%; fish 17.7% versus 5.7% (Gobinaath et al. 2018, as reported in (Krishna et al. 2020)).15
3.3 3.3 Molecular characterisation of India-specific allergens
(Bhattacharya et al. 2018) provides molecular-level data on allergens characterised specifically from Indian clinical populations. The primary food allergen categories identified in Indian patients are legumes, prawn, eggplant, milk, and egg.
India’s only IUIS-registered food allergen is Pen i 1, the tropomyosin of Penaeus indicus (Indian white prawn) (Bhattacharya et al. 2018).16
16 The IUIS (International Union of Immunological Societies) maintains the official registry of characterised allergens — proteins that have been isolated, sequenced, and confirmed as allergenic through clinical data. Registration means the protein has been formally identified and named as an allergen. That India has only one registered food allergen is a measure of how much molecular characterisation work remains, not of how few allergenic foods exist.
17 A protein that resists pepsin digestion for 15 minutes arrives in the gut largely intact — meaning the immune system encounters the full protein rather than fragments. Fragments are generally less likely to trigger a response because the immune system recognises the whole structure, not the parts. Pepsin stability is one of the properties the FAO/WHO uses to assess whether a novel protein is likely to be allergenic.
Black gram (Vigna mungo): A 28-kDa glycoprotein (Vig m) was isolated and shown to resist pepsin digestion for at least 15 minutes, a property associated with higher clinical relevance for IgE-mediated reactions. Sequence homology to a rho-specific inhibitor in peanut was identified, providing a structural basis for observed cross-reactivity (Bhattacharya et al. 2018). 17
Chickpea (Cicer arietinum): A 26-kDa albumin fraction was characterised and found to cross-react with peanut IgE, relevant given that peanut allergy is the best-documented IgE-mediated food allergen globally (Bhattacharya et al. 2018).
Kidney bean (Phaseolus vulgaris): A 31-kDa phytohemagglutinin was found stable to pepsin digestion and reported to sensitise approximately 22% of Delhi food-allergic patients tested (Bhattacharya et al. 2018).
Rice (Oryza sativa): A 24-kDa chitinase was identified as the major allergen; approximately 12% of food-allergic patients in the study were SPT positive (Bhattacharya et al. 2018).
Eggplant (Solanum melongena): A lipid transfer protein (LTP) was characterised in the peel and seeds. LTPs are heat-stable and digestion-resistant, giving them higher clinical relevance than heat-labile proteins. The histamine confound in SPT testing for eggplant does not affect the molecular characterisation, but does affect interpretation of sensitisation rates (Bhattacharya et al. 2018).18
18 A lipid transfer protein is a small plant protein whose biological role is moving lipids — fats — across cell membranes. They are found across many plant foods and are one of the main drivers of cross-reactivity between plant allergens. Because they are heat-stable, they remain allergenic in cooked food, which makes them clinically more significant than proteins that denature under heat.
19 This distinction matters for processed food labelling specifically. A product containing cooked mackerel retains its allergenic proteins intact. A product containing cooked hilsha may carry reduced — though not necessarily zero — allergenic risk. The current FSSAI declaration requirement covers fish as a category and does not distinguish by heat stability.
Fish: Heat-stable allergens were characterised in bhetki (Lates calcarifer) and mackerel (Rastrelliger kanagurta); heat-labile allergens in hilsha (Tenualosa ilisha) and pomfret (Pampus argenteus). Cooking does not eliminate allergenic risk from bhetki or mackerel (Bhattacharya et al. 2018). 19
Legumes as a class: allergen proteins from legumes retain IgE reactivity after gastric digestion (Bhattacharya et al. 2018), which means the pepsin-stability argument applies across the entire legume complex, not only to individual characterised proteins.
(Milana et al. 2025) provides additional cross-reactivity data for the Indian legume complex. Mung bean LTPs share greater than 60% sequence homology with LTPs from lentil, bean, peanut, strawberry, and apple. Black gram (Vig m) cross-reacts with faba bean, lentil, lima bean, and pea. Black gram is also linked to Pollen Food Allergy Syndrome with Prosopis juliflora, a tree species prevalent across urban India (Milana et al. 2025).20
20 Pollen Food Allergy Syndrome (PFAS) is a cross-reactive condition where sensitisation to a pollen triggers oral symptoms — tingling, mild swelling — on eating certain raw foods. The immune system is recognising a structural similarity between the pollen protein and a food protein. In India, Prosopis juliflora is a widespread urban tree; people sensitised to its pollen may develop oral symptoms to black gram through this pathway rather than through direct sensitisation to the legume.
Red gram / pigeon pea (Cajanus cajan): Novel allergens including β-conglycinin and vicilin homologues have been identified via Indian patient sera (Bhattacharya et al. 2018). Sensitisation data from a Karnataka population study (N=2,219) reported 12.6% sIgE positive (Krishna et al. 2020).
3.4 3.4 The sensitisation-reactivity gap
In EuroPrevall India, 19.1% of children tested positive for at least one food by sIgE; 0.14% had probable food allergy — a 136-fold gap (Mahesh et al. 2023; Krishna et al. 2020). For peanut specifically, sensitisation was 6.3% by sIgE; probable peanut allergy was approximately 0.03% — roughly 200-fold (Krishna et al. 2020). In Western populations, peanut allergy prevalence is typically cited at 1–2%, an order of magnitude closer to the sensitisation rate.
Several protective factors have been proposed: longer breastfeeding, vaginal delivery, diverse legume exposure from early life, gut microbiome composition, and enteric helminthiasis (Mahesh et al. 2023).21 None has been confirmed as causal; they are epidemiological associations observed in parallel with the gap.
21 Enteric helminthiasis means intestinal worm infections, which are more common in lower-income settings. This may seem counterintuitive as a protective factor, but the hypothesis is that parasitic infections shift the immune system toward a particular response profile — Th2-dominant — that may reduce clinical reactivity to food allergens. As India urbanises and sanitation improves, helminthiasis rates fall, and the gap may narrow as a result.
The urbanisation signal is indirect evidence for the protective factor hypothesis. Children born in Hong Kong to mainland Chinese parents are approximately four times more likely to develop food sensitisation than mainland-born children, despite identical genetic background (Leung et al. 2024). In Indian data, urban children consistently show higher sensitisation to prawn, peanut, fish, and milk than rural children in the same regional studies (Krishna et al. 2020).
This matters for any classification that uses sensitisation data as a proxy for clinical relevance. For most foods in §3.2, sensitisation rates are the only data available. The gap documented here is the reason those rates cannot be read directly as clinical allergy burden.
3.5 3.5 Why the evidence base is limited
The constraints on Indian food allergy research are structural, not incidental. The researchers working in this field document them explicitly (Krishna et al. 2020; Devdas et al. 2018; Mahesh et al. 2023).
Most sensitisation data comes from allergy clinic patients, not general population cohorts. Patients attending allergy clinics are a selected population — higher pre-test probability of sensitisation than the general population. Rates from these studies are expected to exceed true population prevalence.
Standardised allergen extracts for SPT are not available in India. “High quality allergen extracts for skin tests and adrenaline auto-injectors are currently not available in India” (Krishna et al. 2020). Results vary across laboratories and cannot be pooled directly.22
22 When two labs test for sensitisation to the same food using different extracts — different protein concentrations, different preparation methods — a positive result in one lab is not directly comparable to a positive result in the other. This is why sensitisation rates for the same food vary considerably across Indian studies, and why ranges rather than single figures are reported throughout this review.
Systematic data is largely from Karnataka and Delhi. Northeast India, rural India, coastal fishing communities, and tribal populations are essentially absent from the available literature.
DBPCFC-confirmed data exists for three foods only — rice, black gram, chickpea — each from single-centre clinic cohorts. “Very few studies in India have confirmed food allergy with a challenge procedure” (Mahesh et al. 2023). As recently as 2018, adrenaline auto-injectors were not available in India (Devdas et al. 2018), which limited the ability to conduct challenges safely.23
23 A food challenge carries the risk of triggering the very reaction it is testing for. Conducting one safely requires having emergency treatment — adrenaline — immediately available. Without it, a challenge that triggers anaphylaxis cannot be managed. This is the direct structural link between the absence of adrenaline auto-injectors and the absence of challenge data in the Indian literature.
Evidence generated in high-income Western countries is not directly applicable to India. Diagnostic thresholds, allergen panels, and reference ranges require validation for Indian populations before they can be used (Krishna et al. 2020).
These are the conditions that shaped the evidence. They explain why the literature looks the way it does, and they are the frame within which every figure in §3.1–3.3 should be read.
4 4. The FSSAI mandatory list
4.1 4.1 Regulatory text
Regulation 5(14) of the Food Safety and Standards (Labelling and Display) Regulations, 2020 (Version III, operationalised 1 July 2022) requires that packaged food manufacturers declare the presence of the following allergen groups on the product label (Food Safety and Standards Authority of India 2022):
- Cereals containing gluten (wheat, rye, barley, oats, spelt, and their hybridised strains)
- Crustaceans
- Milk
- Eggs
- Fish
- Peanuts and tree nuts
- Soybeans
- Sulphites at concentrations of 10 mg/kg or more
Exemptions include: oils derived from listed ingredients; distilled alcoholic beverages; raw agricultural commodities; and specific wheat-derived processing aids where gluten content is ≤20 mg/kg (Food Safety and Standards Authority of India 2022).24
24 These exemptions exist because highly refined oils derived from allergenic sources — peanut oil, soy oil — typically contain little to no residual protein, and protein is what the immune system reacts to. The exemption is not blanket; cold-pressed or unrefined oils may retain protein and are treated differently.
“May Contains” declarations for cross-contamination risk are permitted but not required.
4.2 4.2 International basis
The FSSAI 2020 list maps directly to the Codex Alimentarius General Standard for the Labelling of Pre-packaged Foods (CXS 1-1985) as it stood prior to the 2024 revision. India adopted the Codex list as the scientific baseline for its allergen labelling framework, consistent with the WTO Sanitary and Phytosanitary Agreement’s treatment of Codex standards as the international reference (Codex Alimentarius Commission 2024).25
25 The WTO SPS Agreement encourages member countries to base food safety regulations on international standards — primarily Codex — rather than developing independent national standards for each regulated substance. Adopting the Codex allergen list is therefore not a shortcut; it is the standard approach for WTO member states. The question is what happens when the Codex list diverges from national-specific evidence, which is what §4.4 examines.
The Codex 2024 revision made two changes relevant here: sesame was added as a mandatory declaration allergen, and soy was reclassified from mandatory to recommended, reflecting lower confirmed soy allergy prevalence in large population studies relative to other listed allergens (Codex Alimentarius Commission 2024). The 2024 revision also introduced a requirement for visual distinction of allergen declarations from surrounding label text. Whether FSSAI will align with these changes is not known at the time of writing.
The table below places the FSSAI list in international context.
| Allergen | FSSAI 2020 | Codex pre-2024 | Codex 2024 | EU (Big 14) | US (Big 9) |
|---|---|---|---|---|---|
| Gluten-containing cereals | Mandatory | Mandatory | Mandatory | Mandatory | Mandatory (wheat only) |
| Crustaceans | Mandatory | Mandatory | Mandatory | Mandatory | Mandatory |
| Milk | Mandatory | Mandatory | Mandatory | Mandatory | Mandatory |
| Egg | Mandatory | Mandatory | Mandatory | Mandatory | Mandatory |
| Fish | Mandatory | Mandatory | Mandatory | Mandatory | Mandatory |
| Peanuts | Mandatory (with tree nuts) | Mandatory | Mandatory | Mandatory | Mandatory |
| Tree nuts | Mandatory (with peanuts) | Mandatory | Mandatory | Mandatory | Mandatory |
| Soybeans | Mandatory | Mandatory | Recommended | Mandatory | Mandatory |
| Sulphites ≥10 mg/kg | Mandatory | Mandatory | Mandatory | Mandatory | — |
| Sesame | Not listed | Not listed | Mandatory | Mandatory | Mandatory (added 2023) |
| Lupin | Not listed | Not listed | — | Mandatory | — |
| Molluscs | Not listed | Not listed | — | Mandatory | — |
| Celery | Not listed | Not listed | — | Mandatory | — |
| Mustard | Not listed | Not listed | — | Mandatory | — |
4.3 4.3 Where the regulation and the literature converge
Crustaceans show the strongest alignment between regulation and Indian evidence. Prawn tropomyosin (Pen i 1, Penaeus indicus) is India’s only IUIS-registered food allergen (Bhattacharya et al. 2018). Sensitisation data is available from at least four independent Indian studies, with rates ranging from 10.3% to 53.5% depending on study type and population (Krishna et al. 2020).
Milk, egg, and fish all appear in FSSAI with supporting Indian sensitisation data. Milk sensitisation is 1.35–20.5% across reviewed studies; probable food allergy to milk in children was 0.5% of the EuroPrevall India probable food allergy subset (Mahesh et al. 2023). Egg sensitisation was 6.9–34.9% in clinic-based studies; probable egg allergy 0.05% in children (Mahesh et al. 2023). Fish allergens characterised in India include heat-stable proteins in bhetki and mackerel (Bhattacharya et al. 2018).
Peanuts: sIgE sensitisation 6.3–19.6% in Indian data (Mahesh et al. 2023; Krishna et al. 2020); probable food allergy approximately 0.03% — the sensitisation-reactivity gap at its most pronounced.
Wheat (gluten cereals): sIgE sensitisation 6.7–11.93%; probable food allergy 0–0.02% in EuroPrevall India (Mahesh et al. 2023).
4.4 4.4 Where the regulation and the literature diverge
Several foods with documented Indian sensitisation data are absent from the FSSAI list. For a regulatory body setting mandatory labelling requirements, the relevant standard is confirmed clinical allergy burden — and for most of these foods, the DBPCFC data to establish that burden does not exist in India-specific form.26
26 Mandatory labelling requirements carry legal and commercial consequences for manufacturers. Setting that bar requires a level of confirmed evidence — ideally challenge-confirmed allergy at population scale — that is higher than what is needed to flag a food as potentially relevant in a research taxonomy. The absence of a food from the FSSAI list does not mean it is not allergenic; it means the evidentiary bar for a legal mandate has not been cleared.
The foods where the evidence is most developed:
Sesame: sensitisation 8.0% in EuroPrevall India children — higher than peanut (6.3%) (Mahesh et al. 2023). Codex 2024 has since added sesame as mandatory, joining the US (since 2023) and the EU (Codex Alimentarius Commission 2024). The evidence position for sesame has materially changed since the FSSAI 2020 list was written.
Rice, black gram, and chickpea each have Indian DBPCFC data: rice (6 of 16 confirmed), black gram (4 of 14 confirmed), chickpea (31 of 41 confirmed) (Mahesh et al. 2023; Krishna et al. 2020). These are small single-centre cohorts and the only India-specific challenge data that exists for any food not on the FSSAI list.
The Indian legume complex — pigeon pea, kidney bean, lentil, green gram — has documented sensitisation, characterised allergen proteins, and pepsin-stable fractions (Bhattacharya et al. 2018; Krishna et al. 2020). No OFC data is available. Legume proteins as a class retain IgE reactivity after gastric digestion (Bhattacharya et al. 2018), and the cross-reactive epitopes across this complex mean primary sensitisation to one legume may carry risk across others.
Eggplant is named among the five primary Indian food allergens by (Bhattacharya et al. 2018), appears in the adult allergen profile of EuroPrevall (Mahesh et al. 2023), and has a characterised LTP. SPT-based sensitisation figures carry the histamine confound noted in §3.2; the molecular evidence does not.
Mustard has no India-specific clinical allergy data in the reviewed literature but is mandatory in the EU, widely used in Indian cooking as both oil and spice, and subject to ongoing FAO/WHO threshold assessment.
4.5 4.5 The regulatory process as a constraint on list updates
Adding a food to a mandatory allergen declaration list is not a scientific decision alone. It is a regulatory action with legal, commercial, and administrative consequences, and the process that produces it reflects that.
A mandatory declaration requires that manufacturers identify the allergen across their entire supply chain, verify its presence or absence in every product, update labels, and retrain procurement and production staff. For large manufacturers with complex ingredient sourcing, this is a substantial operational exercise. For small manufacturers — which constitute a significant portion of India’s packaged food sector — it can be the difference between compliance being feasible or not. Regulators setting a new mandatory requirement are not only making a safety call; they are also setting a compliance burden, and the timeline and scope of that burden are part of the decision.
Enforcement is a parallel constraint. A mandatory declaration is only as useful as the regulator’s ability to verify it. For allergens with standardised, widely available testing methods, enforcement is tractable. For allergens where testing methodology is not yet standardised — or where reference materials are not available in India — a mandatory declaration creates a requirement that inspection infrastructure cannot yet reliably verify. Regulators have reason to wait until enforcement is feasible before making a requirement mandatory rather than recommended.
The evidentiary standard for a mandatory declaration is also necessarily higher than for a research classification. A regulation that mandates disclosure of an allergen on the basis of sensitisation data alone — without challenge-confirmed allergy at meaningful scale — risks requiring declarations for foods that carry negligible clinical risk in practice, which dilutes the signal value of the mandatory list for consumers and manufacturers alike. The regulatory instinct to wait for confirmed data before acting is not conservatism for its own sake; it is the same instinct that makes the list meaningful when it does require something.
International alignment adds a further dimension. India’s participation in Codex and its WTO commitments create a shared interest in regulatory coherence across borders — both for consumer protection and for the practical functioning of food trade. Moving significantly ahead of or behind international standards has consequences that extend beyond the immediate safety question. The Codex process itself reflects this: the 2024 revision that added sesame and reclassified soy took years of evidence review and member state consultation before it was adopted. That pace is not a failure of urgency — it is what thorough cross-jurisdictional alignment requires.
None of this means the FSSAI list is final. It means the list reflects what was possible to establish, mandate, and enforce at the time it was written, under the conditions that existed. The divergence between the list and the clinical literature documented in §4.4 is not a gap that went unnoticed — it is a gap that the regulatory process has not yet closed, for reasons that are themselves part of the record.
5 5. Limitations
The limitations of this review are the limitations of the underlying evidence base.
Geographic coverage: All EuroPrevall-INCO data comes from Mysore and Bengaluru. Most clinic-based studies are from Delhi or Kolkata. No systematic food allergy data from Northeast India, rural India, coastal fishing communities, tribal populations, or most of North India is available in the reviewed literature.27
27 India’s dietary diversity means that allergen exposure varies considerably by region — a coastal community in Kerala will have systematically different fish and shellfish exposure than an inland population in Rajasthan. A sensitisation pattern that holds in urban Karnataka may not hold elsewhere. The geographic concentration of the available data is not a minor caveat; it means the review describes what is known about food allergy in a specific part of India, not India as a whole.
Study design: Most sensitisation data comes from allergy clinic patients, not general population cohorts. Patients attending allergy clinics are a selected population — higher pre-test probability of sensitisation than the general population. Rates from these studies are expected to exceed true population prevalence.
Diagnostic method: The 0.14% (children) and 1.2% (adults) figures use the EuroPrevall probable food allergy definition — reported symptoms within two hours combined with positive sIgE or SPT. This is not OFC-confirmed diagnosis. DBPCFC-confirmed data exists only for rice (6/16), black gram (4/14), and chickpea (31/41), each from single-centre clinic cohorts.
Eggplant confound: Stored eggplant accumulates histamine at levels that can produce false-positive SPT results. Eggplant sensitisation rates from SPT-based studies should be interpreted with this confound in mind (Bhattacharya et al. 2018). The LTP characterisation from (Bhattacharya et al. 2018) provides molecular evidence independent of SPT.
Cross-reactivity vs primary sensitisation: Some sensitisation data, particularly for legumes, may reflect cross-reactivity with a primary sensitiser rather than independent sensitisation to the food tested. The Indian legume complex has documented cross-reactive epitopes (Bhattacharya et al. 2018; Milana et al. 2025). A patient with primary sensitisation to black gram may test positive for lentil, pea, and faba bean without independent primary sensitisation to those foods.28
28 This complicates the interpretation of sensitisation rates for individual legumes. If a significant fraction of lentil-positive results in Indian clinic studies reflect cross-reactivity with black gram rather than primary lentil sensitisation, the true lentil-specific sensitisation rate would be lower than reported. Disentangling primary sensitisation from cross-reactivity requires molecular testing — component-resolved diagnostics — which is not available in most Indian clinical settings.
Trajectory uncertainty: India’s food allergy landscape is not static. Urbanisation is consistently associated with higher food allergy rates in Asia-Pacific data (Leung et al. 2024), and India is urbanising rapidly. Current prevalence figures from 2006–2020 studies may not reflect the position in five or ten years. The allergen list derived from this review reflects evidence available through early 2026.
FSSAI update status: Whether FSSAI intends to align with the Codex 2024 revision is not known at the time of writing.
6 6. An extended allergen recognition list for Indian food systems
A mandatory labelling regulation and a research classification are doing different things. A regulation sets a legal threshold — what manufacturers must declare, with consequences for non-compliance. A classification organises information for researchers, analysts, and developers working with ingredient data. A higher evidentiary bar is appropriate for a legal mandate than for a classification flag.29
29 This distinction matters because it explains why the list below includes foods that FSSAI does not mandate. The question being asked is different: not “what is confirmed enough to require by law” but “what is documented enough in Indian-specific evidence to warrant flagging as allergen-relevant.” The two questions have different answers.
The list has three tiers.
6.1 Tier 1 — FSSAI core 8
These eight allergen groups are mandatory declarations under FSSAI Regulation 5(14) (Food Safety and Standards Authority of India 2022). Adopted unchanged.
| # | Allergen group | FSSAI reference | Indian evidence summary |
|---|---|---|---|
| 1 | Gluten-containing cereals | Reg 5(14)(i) | Wheat: 6.7–11.93% sIgE; 0–0.02% probable FA in children |
| 2 | Crustaceans | Reg 5(14)(ii) | Prawn: 10.3–53.5% sensitisation; Pen i 1 India’s only IUIS-registered food allergen |
| 3 | Milk | Reg 5(14)(iii) | 1.35–20.5% sensitisation; 0.5% probable FA in children’s probable FA subset |
| 4 | Egg | Reg 5(14)(iv) | 6.9–34.9% sensitisation; 0.05% probable FA in children |
| 5 | Fish | Reg 5(14)(v) | Heat-stable allergens in bhetki and mackerel; heat-labile in hilsha and pomfret |
| 6 | Peanuts and tree nuts | Reg 5(14)(vi) | Peanut: 6.3–19.6% sensitisation; ~0.03% probable FA |
| 7 | Soybeans | Reg 5(14)(vii) | Limited India-specific data; Codex 2024 reclassified as recommended |
| 8 | Sulphites (≥10 mg/kg) | Reg 5(14)(viii) | Chemical sensitivity; not a protein allergen |
6.2 Tier 2 — Literature additions
These nine allergen groups are absent from FSSAI 2020 but have supporting evidence from Indian clinical or epidemiological literature. The type and strength of evidence is noted for each.
| # | Allergen | Evidence | Sources |
|---|---|---|---|
| 9 | Sesame | 8.0% sIgE in EuroPrevall India children; Codex 2024 added as mandatory; US and EU both include sesame | (Mahesh et al. 2023; Codex Alimentarius Commission 2024) |
| 10 | Black gram (Vigna mungo) | DBPCFC 4 of 14 confirmed; 28-kDa Vig m; resistant to pepsin digestion; cross-reacts with lentil, faba bean, lima bean, pea | (Krishna et al. 2020; Bhattacharya et al. 2018; Milana et al. 2025) |
| 11 | Chickpea (Cicer arietinum) | DBPCFC 31 of 41 confirmed; anaphylaxis documented; 26-kDa albumin cross-reacts with peanut IgE | (Devdas et al. 2018; Krishna et al. 2020; Bhattacharya et al. 2018) |
| 12 | Kidney bean (Phaseolus vulgaris) | 22% sensitisation in Delhi food-allergic population; 31-kDa allergen stable to pepsin; cross-reacts with peanut, black gram, lentil, pea | (Bhattacharya et al. 2018) |
| 13 | Lentil (Lens culinaris) | 5.5–9.7% sensitisation (Delhi, N=216–1,860); cross-reacts with black gram, kidney bean, pea | (Krishna et al. 2020; Milana et al. 2025) |
| 14 | Rice (Oryza sativa) | DBPCFC 6 of 16 confirmed; 12% SPT positive in food-allergic population; 24-kDa chitinase as major allergen | (Bhattacharya et al. 2018; Mahesh et al. 2023) |
| 15 | Eggplant (Solanum melongena) | Named among five primary Indian food allergens; 4.3% SPT-confirmed community study (N=741); LTP in peel and seeds; SPT figures carry histamine confound | (Bhattacharya et al. 2018; Krishna et al. 2020) |
| 16 | Mustard (Brassica spp.) | Mandatory in EU; widely used in Indian cooking; FAO/WHO threshold assessment ongoing; no India-specific clinical data in reviewed literature | (Food Safety and Standards Authority of India 2022; Codex Alimentarius Commission 2024) |
| 17 | Pigeon pea / red gram (Cajanus cajan) | Novel allergens identified via Indian patient sera; 12.6% sIgE in Karnataka population study (N=2,219) | (Bhattacharya et al. 2018; Krishna et al. 2020) |
6.3 Tier 3 — Flagged; insufficient evidence for inclusion
These foods have some Indian relevance but insufficient evidence to include in Tier 1 or Tier 2. Documented here for transparency and future review.
| Allergen | Available evidence | What is missing |
|---|---|---|
| Mung bean (Vigna radiata) | IUIS allergens Vig r1–r6 characterised; 12.5% sIgE in one Karnataka study; LTPs cross-reactive with peanut, soy, lentil, strawberry, apple, peach (Milana et al. 2025) | India-specific OFC or DBPCFC data; cross-reactivity with black gram may explain observed sensitisation |
| Banana | 3.6–40.6% sensitisation range across Indian studies | OFC data; wide range suggests heterogeneous testing and possible cross-reactivity |
| Betel leaf (Piper betle) | Widely used in Indian food culture; reported as an exposure of concern in community settings | No molecular characterisation or clinical allergy data |