Side effects of egg protein
Egg protein is considered one of the safest protein sources, but it too can cause adverse reactions — from unpleasant bloating to a serious allergy. Our editorial team examined which side effects are actually described, why they occur, and how to avoid them.
General safety profile
Egg protein is dried and pasteurized egg white, that is, a product that humanity has consumed for thousands of years in ordinary food. Therefore, for most people it is safe, and its side effects mostly come down to digestive reactions and, less often, allergy.
At the same time, the concentrated form changes the picture: a serving of powder can contain as much protein as 6–8 egg whites and is consumed quickly. This increases the likelihood of GI discomfort and makes allergic reactions in sensitive people potentially stronger.
Our editorial team examines the side effects in order from the most common to the most serious, and also explains who should be especially attentive to this product.
The diagram shows: the most common reactions are digestive and mild, while the most serious — allergic — occur less often but require the greatest attention.
Digestive reactions: bloating, gas, nausea
The most common complaints about egg protein are bloating, increased gas formation, and a feeling of heaviness. Egg white is rich in the sulfur-containing amino acids methionine and cysteine. The portion of them not absorbed in the small intestine is fermented by the microflora of the large intestine with the formation of sulfur compounds, which give the gas its characteristic unpleasant smell.
The intensity of these symptoms depends on the dose per intake, the speed of consumption, and the overall composition of the diet. A large portion of protein drunk on an empty stomach in a minute more often causes discomfort than the same amount spread across meals.
Another cause of digestive complaints is not the protein itself but the additives in the product: sugar alcohols (erythritol, sorbitol, maltitol), thickeners, inulin. They can cause bloating and looser stools, especially in people with irritable bowel syndrome.
Some users note nausea associated with the specific taste and smell of egg protein. Here it helps to choose products with quality flavorings or to use the powder in dishes — pancakes, omelets, baked goods.
Egg allergy: the main serious risk
Egg allergy is one of the most common food allergies in children; in most of them it resolves with age, but in some it persists into adulthood (Caubet, Wang, 2011). The main allergens are contained precisely in egg white: ovomucoid, ovalbumin, ovotransferrin, and lysozyme.
Ovomucoid is especially important: it is resistant to heat and digestive enzymes. Therefore pasteurization, which makes egg protein safer microbiologically, does not eliminate its allergenicity. For people with an egg allergy, egg protein is contraindicated.
Manifestations of allergy vary from mild — itching in the mouth, hives, a runny nose — to severe: laryngeal edema, bronchospasm, a drop in blood pressure, anaphylaxis. Severe reactions require emergency medical care.
For people who have atopic dermatitis, asthma, or other allergies, our editorial team advises trying a new protein with caution: start with a small amount and monitor the reaction. If there was ever a reaction to eggs in childhood, it is worth consulting an allergist before taking it.
| Allergen | Feature | Significance for the powder |
|---|---|---|
| Ovomucoid | Heat-stable, resistant to enzymes | Retains allergenicity after pasteurization |
| Ovalbumin | The most common protein | Partly changed by heating |
| Ovotransferrin | Binds iron | Can be an allergen in sensitive people |
| Lysozyme | Also used as a food additive | May be present in other products too |
Other possible risks
Biotin and avidin.Raw egg white contains avidin, which binds biotin (vitamin B7) and can cause its deficiency with prolonged consumption of large amounts of raw whites. Pasteurization and heating largely inactivate avidin, so for a quality powder this risk is minimal.
Microbiological safety.Raw eggs can be a source of salmonella. Pasteurized powder from a reliable manufacturer practically eliminates this risk. In contrast, a “homemade” replacement of protein with raw eggs is dangerous and less effective: the digestibility of raw white is much lower (Evenepoel et al., 1998).
Kidneys.The systematic review and meta-analysis by Devries and colleagues (2018) found no deterioration of kidney function in healthy adults on a high-protein diet. However, for people with chronic kidney disease the amount of protein is limited by a doctor, and any protein without their agreement is undesirable.
Sodium.Dried egg white contains a noticeable amount of sodium. People with hypertension or on salt restriction should take this into account in their daily diet.
Cholesterol.Whole-egg products contain yolk cholesterol. For most people dietary cholesterol is less important than saturated fats, but patients with hypercholesterolemia had better discuss their diet with a doctor.
How to reduce the likelihood of side effects
Most troubles with egg protein can be prevented by simple steps:
- start with half a serving and gradually increase;
- split the daily amount into several intakes of 20–30 g;
- mix with water or a plant-based drink and drink slowly;
- choose products without sugar alcohols if you are prone to bloating;
- buy only pasteurized products with a transparent composition and allergen labeling;
- at any signs of allergy, stop taking it immediately.
It is also useful to monitor the overall diet: an adequate amount of fiber, fluid, and varied protein sources reduces the load on the intestine.
If bloating persists even at small doses, you can try another protein source — whey isolate, hydrolysate, or plant proteins.
In case of chronic kidney, liver, or cardiovascular diseases, it is worth consulting a doctor before taking it.
Editorial conclusions
Egg protein is safe for most healthy people. The most common side effects — bloating, gas, and nausea — are dose-dependent and usually easily corrected.
The main serious risk is egg allergy. Heat-stable ovomucoid is not destroyed by pasteurization, so the product is contraindicated for people with an allergy.
For healthy kidneys, a high-protein diet is not harmful according to the available data, but in chronic kidney disease the amount of protein is determined by a doctor.
Also read our articles “Egg protein: what it is and how it works,” “How to take egg protein,” and “The benefits of egg protein for athletes.”
References
- Caubet JC, Wang J. Current understanding of egg allergy. Pediatr Clin North Am. 2011;58(2):427–443.
- Evenepoel P, Geypens B, Luypaerts A, Hiele M, Ghoos Y, Rutgeerts P. Digestibility of cooked and raw egg protein in humans as assessed by stable isotope techniques. J Nutr. 1998;128(10):1716–1722.
- Devries MC, Sithamparapillai A, Brimble KS, Banfield L, Morton RW, Phillips SM. Changes in kidney function do not differ between healthy adults consuming higher- compared with lower- or normal-protein diets: a systematic review and meta-analysis. J Nutr. 2018;148(11):1760–1775.
- Jäger R, Kerksick CM, Campbell BI, et al. International Society of Sports Nutrition position stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20.
- Schaafsma G. The protein digestibility-corrected amino acid score. J Nutr. 2000;130(7):1865S–1867S.
- Morton RW, Murphy KT, McKellar SR, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med. 2018;52(6):376–384.
Andriy Melnyk
A strength-sports coach and author of programs for beginner and intermediate levels. Writes about training planning.
