My out-of-print book, Living with Food Allergy, is now grossly out-of-date in most respects, but there is an appendix in it on Food Families which remains relevant and may be useful to many, and which I thought I’d make available on the Allergy Insight website for the first time.
Cross-reactions often occur between closely related foods — if you’re diagnosed allergic to one, you may also react to one of its close siblings or cousins.
The following can give an indication of those you might potentially react to should you be allergic to one or more of its family members, although there is unlikely to be any reason to avoid a food you presently consume without problem.
Use this list with discretion and caution, then, for instance to identify a potential source of a reaction you can’t otherwise explain — but not to unnecessarily restrict your diet further without good reason.
Always confirm a suspicion with your consultant, who can facilitate testing, if needs be.
Any not categorised below are likely to form one-member groups, with no common close edible relatives — examples include amaranth, bananas (including plantains), capers, coffee, elderberry, linseed, ginkgo biloba, ginseng, grapes, kiwi, lychee, olives, papaya, peppercorns, persimmon, pineapple, poppy seed, sesame, sweet potato, tea and vanilla, as well as many of the tree nuts.
However, being an ‘only child’ is not necessarily predictive of a food’s reactive potential — kiwis are commonly allergenic, for instance, while tea is not.
Besides, cross-reactions are also possible between unrelated foods. The tree nuts are a case in point. Although many are individualists, they often cross-react with one another, and with peanut, a legume, and almond, a rose member. It’s a similar picture with many seeds.
People with Pollen Food Syndrome / Oral Allergy Syndrome may especially find the following useful.
Angelica, aniseed, caraway, carrot, celeriac, celery, chervil, coriander, cumin, dill, fennel, lovage, parsley, parsnip.
Bergamot, grapefruit, lemon, lime, kumquat, orange, tangerine, and hybrids such as clementine and ugli.
Artichoke (globe and Jerusalem), burdock, camomile, cardoon, chicory, dandelion, echinacea, endive, feverfew, lettuce, milk thistle, salsify, safflower, sunflower, tarragon.
Beetroot, chard, spinach, sugar beet; also, but more distantly, quinoa.
A large family providing many edible grains. As far as cross-reactions go, the following sub-families are more relevant:
- Barley, Kamut, rye, spelt, triticale, wheat; also, but more distantly, oats;
- Corn / maize, millet, sorghum, sweetcorn;
- Rice, wild rice.
Alfalfa, beans (such as broad, butter, haricot, kidney, mung, runner, soya — but not cocoa), carob (locust bean), chickpea, fenugreek, lentil, liquorice, lupin, mangetout, pea, peanut, tamarind — and any edible sprouts, such as beansprouts or peanut shoots. Also, legumes used to make additive gums or supplements — acacia, clover, guar, senna, tara, tragacanth.
Aloe vera, asparagus, chives, garlic, leek, onion, shallot, spring onion.
Cucumber, courgette, marrow, melon (all varieties, including honeydew and watermelon), pumpkin, squash.
Broccoli, Brussels sprouts, cabbages, cauliflower, Chinese leaf, collard greens, cress, horseradish, kale, kohlrabi, mustard, pak choi, radish, rape (canola), rocket, swede (rutabaga), turnip, watercress.
Peppers (capsicum and chilli, as well as paprika), physalis (cape gooseberry), potato, tomato; also aubergine, but cross-reactions with it seem rare.
A large family that gives us many fruits. With regard to cross-reactions, these subdivisions are more pertinent:
- apricot, cherry, damson, greengage, nectarine, peach, plum/prune, sloe — also almond;
- apple, pear, quince;
- blackberry, boysenberry, loganberry, raspberry.
All the above families appear to be the most relevant in food allergic reactions, especially when sensitivity to pollen is involved. The following appear less so, and their members may be less likely to cross-react. This is especially true when different parts of the plants are used as food — as with the laurels, where fruits (avocado), leaves (bay) and bark (cinnamon) are consumed.
- cashew family (cashew, mango, pistachio);
- currant family (blackcurrant, gooseberry, redcurrant);
- deadnettle family (basil, lavender, mint, marjoram, oregano, rosemary, sage, thyme);
- ginger family (cardamom, ginger, turmeric);
- knotweed family (buckwheat, rhubarb, sorrel);
- laurel family (avocado, bay, camphor, cinnamon);
- mulberry family (breadfruit, fig, jackfruit, mulberry);
- myrtle family (allspice, clove, eucalyptus, guava);
- palm family (coconut, date, palm, saw palmetto).
These divide into three distinct categories — fish, crustaceans and molluscs — the first and third being sub-divided further.
In general, the closer related any two sea animals are, the more likely you will experience cross-reactions between them — in the case of fish, cross-reactions between bony fish and cartilagenous fish are the least likely.
Crustaceans and molluscs are often grouped together colloquially as ‘shellfish’. There is some evidence that the likelihood of cross-reactions between these two groups is higher than that between either group and fish.
Cartilagenous fish form one class — members are monkfish, ray, shark and skate.
Bony fish form a numerically dominant class, and can be divided into a number of orders, the following of which are the most important:
- clupeiformes — anchovy, herring, pilchard/sardine, sprat;
- gadiformes — cod, haddock, hake, whiting;
- perciformes — bass, bream, mackerel, perch, red mullet, snapper, swordfish, tuna, yellowtail;
- pleuronectiformes — flounder, halibut, plaice, sole, turbot;
- salmoniformes — pike, salmon, trout, whitefish.
Crab, crayfish, langouste, lobster, prawn, shrimp.
- bivalves — clam, cockle, mussel, oyster, scallop, whelk;
- cephalopods — cuttlefish, octopus, squid;
- gastropods — abalone, limpet, periwinkle, snail.