Food Allergies: How to Build an Athlete's Diet

A food allergy does not prohibit playing sports, but it requires more careful meal planning: products that usually provide protein, calcium, iodine or omega-3 fatty acids drop out of the diet. The editors examined how to build a complete diet for an athlete with an allergy without losing either performance or safety.

Allergy, intolerance and "fashionable" restrictions

A food allergy is a reaction of the immune system to a food protein. Most often it is mediated by antibodies of the IgE class: within minutes or hours of contact with the allergen, hives, swelling, itching in the mouth, vomiting and difficulty breathing occur, and in the most severe cases - anaphylaxis. There are also non-IgE-mediated forms, which develop more slowly and more often affect the digestive tract.

Food intolerance is a fundamentally different phenomenon. The best-known example is lactase deficiency: a person lacks the enzyme to break down milk sugar, and an excess of lactose causes bloating and diarrhea. This is unpleasant but not life-threatening, and small amounts of the product are often tolerated well. For an athlete the difference is critical: with an allergy even a trace amount matters, with intolerance the dose does.

The third category is self-imposed restrictions without a medical diagnosis. Giving up gluten "for better well-being" is common among athletes. A study by Lis and colleagues showed that a significant proportion of athletes without celiac disease follow a gluten-free diet, although there is no convincing evidence of improved results in them. Such restrictions also narrow the diet and may mask the real cause of complaints.

Therefore the first step is to confirm the diagnosis with an allergist. Skin tests and specific IgE testing show only sensitization; the doctor assesses clinical significance taking the history into account, and if necessary with a supervised challenge test. The EAACI recommendations stress: unjustified exclusion of foods on the basis of tests alone leads to unnecessary deficiencies.

Separately worth mentioning is oral allergy syndrome: itching in the mouth from raw apples, pears or nuts in people allergic to birch pollen. Heat treatment often destroys the responsible proteins, so a baked apple may be entirely safe. Such nuances make it possible not to strike whole food groups from the menu.

Main allergens and risks to the diet

EU legislation (Regulation No 1169/2011) defines 14 allergens whose presence a manufacturer is obliged to declare on the label: gluten-containing cereals, crustaceans, eggs, fish, peanuts, soy, milk, nuts, celery, mustard, sesame, sulfites, lupin and mollusks. As Ukraine adapts its food legislation, it is moving toward the same requirements.

For an athlete, what matters is not only the fact of exclusion but also what "job" the product did in the diet. Milk is protein, calcium, iodine and vitamin B2. Eggs are a convenient complete protein and choline. Fish is the main source of EPA/DHA and vitamin D. Wheat is a significant share of carbohydrates and fiber. When several such products are excluded at once, the risk of deficiencies rises substantially.

One must remember cross-reactions. A person allergic to cow's milk often reacts to goat's milk as well; with a peanut allergy a reaction to lupin sometimes occurs; crustaceans and mollusks can cross-react with each other. These details are determined by an allergist, not by a table on the internet.

Finally, in children an allergy to milk and eggs often resolves with age, whereas an allergy to peanuts, nuts, fish and crustaceans more often persists for life. So an adult athlete who was diagnosed in childhood should be re-examined: perhaps some of the restrictions can already be lifted.

How to meet protein and micronutrient needs

The general needs of an athlete with an allergy are the same as those of other athletes. The position statement of the Academy of Nutrition and Dietetics, Dietitians of Canada and the ACSM recommends 1.2-2.0 g of protein per kilogram of body weight per day for most trained people, distributed over several meals. Carbohydrates are dosed depending on the volume of exertion. The task is to assemble these figures from permitted products.

With a milk allergy the main problem is calcium. It can be obtained from fortified plant drinks (choose those marked as calcium-added), canned fish with bones (if there is no fish allergy), broccoli, almonds (if there is no nut allergy), mineral waters with a high calcium content. If it is impossible to meet the requirement through food, a doctor may prescribe a supplement.

With a fish allergy, omega-3 fatty acids need separate attention. Plant alpha-linolenic acid from flax or walnuts is converted to EPA and DHA in small amounts, so a more practical alternative is microalgae oil - the primary source of DHA in the food chain. It is also worth monitoring vitamin D levels, especially in winter.

On a gluten-free diet an athlete can easily fall short on carbohydrates: bread and pasta disappear, and substitutes are not always at hand. Rice, potatoes, sweet potatoes, buckwheat, corn grits and fruit fully cover the needs even during high-volume training blocks. The only important thing is to plan snacks in advance, so as not to be left without fuel while away.

• Make a list of "basic" safe products in each group: protein, carbohydrates, fats, vegetables.
• Plan the menu for the week and prepare portions in advance - this reduces the risk of accidental contact with the allergen.
• Once a year, assess your nutritional status together with a doctor: ferritin, vitamin D, and if needed calcium and B12.
• Work with a sports dietitian if two or more main products are excluded.

Sports nutrition and labeling

Protein powders are one of the riskiest categories for people with an allergy. Whey and casein protein are milk proteins, so with a milk allergy they are contraindicated, even if the product is low in lactose. A whey isolate solves the lactose problem but not the allergy: the allergenic proteins do not go anywhere.

An alternative is beef, egg (if there is no egg allergy), pea, rice or a combined plant protein. It should be borne in mind that plant sources have less leucine, so it is useful to combine different proteins or slightly increase the serving. Soy isolate is a complete protein source, but soy itself is on the list of main allergens.

Read the label carefully: under EU requirements, allergens are highlighted in the ingredients. The phrase "may contain traces of..." means that the corresponding raw material is used at the facility and cross-contamination cannot be ruled out. For a person with a severe allergy, such a product is better not bought, even if the allergen itself is not listed in the composition.

Bars, gainers and "sports baked goods" often contain peanuts, nuts, milk proteins, soy and gluten all at once. Energy gels and isotonic drinks are usually simpler in composition, but they too should be checked, especially flavored variants. A useful habit is to bring your own verified food supply to a competition and not rely on feed stations.

For athletes competing in official events, one more requirement is relevant - to choose supplements that have passed independent testing for banned substances. This has nothing to do with allergy, but combining the two criteria narrows the choice even further, so the assortment should be assembled in advance.

Exercise-associated anaphylaxis

There is a special form of allergy that concerns athletes specifically - food-dependent exercise-induced anaphylaxis. A person may calmly eat a product at rest and calmly train on an empty stomach, but the combination of these two factors within a few hours causes a severe reaction. Wheat, in particular the protein omega-5-gliadin, is most often described as the trigger.

It is believed that exertion enhances the absorption of the allergen from the intestine, changes blood flow and lowers the threshold for activation of immune cells. Additional cofactors are non-steroidal anti-inflammatory drugs, alcohol, sleep deprivation, heat, menstruation. That is why the reaction may not occur every time, which complicates diagnosis.

The practical recommendations described in the literature come down to avoiding the trigger product for a few hours before training, refraining from NSAIDs before exertion, and training in company. People with diagnosed anaphylaxis are prescribed an adrenaline auto-injector by a doctor, which should always be carried - in the sports bag, not in the locker room.

Coaches and teammates should know about the diagnosis and be able to recognize the first signs: itching, redness, swelling of the lips, hoarseness, dizziness. Anaphylaxis is an emergency: adrenaline is administered immediately, and then an ambulance is called even if the condition improves.

For teams that travel to training camps, it is useful to have a written action plan for an allergic reaction and to agree the menu with the venue's kitchen in advance. This is a simple organizational thing that genuinely saves lives.

Editorial conclusions

A food allergy is not a death sentence for an athletic career. The key is a clear diagnosis, an understanding of which nutrients the excluded product "takes away," and a well-thought-out system of substitutions.

The most vulnerable spots of the diet are protein and calcium with a milk allergy, omega-3 and vitamin D with a fish allergy, carbohydrates on a gluten-free diet. All of them are covered by ordinary foods if meals are planned in advance.

Sports nutrition requires meticulous label reading, and exercise-associated anaphylaxis requires a separate safety plan and constant access to adrenaline as prescribed by a doctor.

The editors also recommend reading our materials on choosing a plant protein, on vitamin D in athletes and on nutrition before competition.

References

1. Muraro A, Werfel T, Hoffmann-Sommergruber K, et al. EAACI food allergy and anaphylaxis guidelines: diagnosis and management of food allergy. Allergy. 2014;69(8):1008–1025.
2. Sicherer SH, Sampson HA. Food allergy: a review and update on epidemiology, pathogenesis, diagnosis, prevention, and management. J Allergy Clin Immunol. 2018;141(1):41–58.
3. Thomas DT, Erdman KA, Burke LM. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: nutrition and athletic performance. J Acad Nutr Diet. 2016;116(3):501–528.
4. Lis DM, Stellingwerff T, Shing CM, et al. Exploring the popularity, experiences, and beliefs surrounding gluten-free diets in nonceliac athletes. Int J Sport Nutr Exerc Metab. 2015;25(1):37–45.
5. Feldweg AM. Food-dependent, exercise-induced anaphylaxis: diagnosis and management in the outpatient setting. J Allergy Clin Immunol Pract. 2017;5(2):283–288.
6. Regulation (EU) No 1169/2011 of the European Parliament and of the Council on the provision of food information to consumers. Official Journal of the European Union. 2011;L304:18–63.