Donkey Milk Alpha-Lactalbumin

Donkey milk alpha-lactalbumin is a key whey protein that plays an essential role in lactose synthesis and contributes to the unique nutritional and functional properties of donkey milk.

 With a whey protein profile that more closely resembles human milk—marked by higher levels of alpha-lactalbumin and lower levels of the allergenic beta-lactoglobulin—donkey milk is increasingly considered a hypoallergenic alternative for individuals with cow milk protein allergy and others seeking alternative dairy options.

What Is Donkey Milk Alpha-Lactalbumin?

Alpha-lactalbumin is a major whey protein found in the milk of most mammals, which plays an important role in lactose synthesis. 

Donkey milk's whey protein profile contains alpha-lactalbumin, which contributes to its potential nutritional and functional properties. Given the structural similarities between donkey milk and human milk, some individuals seek it as an alternative to cow's milk, particularly in cases of cow milk protein allergy (CMPA).

Beta-lactoglobulin, a major whey protein and common allergen in cow milk, is present in significantly lower amounts in donkey milk. This may contribute to its hypoallergenic properties and better tolerability for individuals with cow milk protein allergy.

How Does Donkey Milk Differ From Other Milks?

Donkey milk has a unique composition compared to cow milk and human milk. Key characteristics include:

• Lower fat content than cow and human milk.
• Higher lactose content, making it more similar to human milk.
• A whey protein composition closer to human milk, including alpha-lactalbumin as a dominant whey protein.

Donkey milk is low in fat-soluble vitamins (A, D, E, K) compared to cow milk (but higher in vitamin D than human milk) while also being higher in water-soluble vitamins (B-complex and vitamin C) than cow milk.

Donkey Milk Supplementation in Children

Donkey milk is low in fat, cholesterol, total protein, and casein, but high in lactose, whey proteins, calcium, selenium, and vitamin D3, making it nutritionally closer to human milk than cow milk. 

However, due to its low fat content, donkey milk must be supplemented with additional fat if used as part of a child's diet to ensure adequate caloric intake for growth and development.

Specific Properties of Donkey Milk Alpha-Lactalbumin

The following properties are associated with donkey milk alpha-lactalbumin:

Structural Characteristics

Alpha-lactalbumin in donkey milk shares similarities with human alpha-lactalbumin, which may influence its digestibility and potential benefits.

Bioactive Peptides

Donkey milk contains bioactive proteins, including alpha-lactalbumin, lysozyme, and lactoferrin, which have antimicrobial, anti-inflammatory, and potential antitumor properties. 

Alpha-lactalbumin in donkey milk shares similarities with human alpha-lactalbumin, which in complex with oleic acid (called HAMLET, or Human Alpha-lactalbumin Made Lethal to Tumor cells) has shown tumor-selective apoptotic activity. 

Additionally, lysozyme and lactoferrin contribute to donkey milk’s antimicrobial effects, supporting gut health and immune function.

Who Might Consume Donkey Milk Containing Alpha-Lactalbumin?

The following people might benefit from choosing donkey milk:

Individuals with Cow Milk Protein Allergy (CMPA)

Some individuals with CMPA may tolerate donkey milk due to its different protein profile, though medical supervision is essential. Cross-reactivity can still occur, and not all individuals with CMPA will tolerate donkey milk proteins.

Individuals Seeking Alternative Milk Sources

Donkey milk may be used as an alternative to cow milk for those looking for a different taste, perceived health benefits, or a more digestible protein profile.

Infants (Under Medical Supervision Only)

In rare cases, donkey milk has been used as an alternative for infants when standard formulas or breastfeeding are not options. However, it lacks some essential nutrients found in infant formulas, so it should only be used under strict medical guidance.

Donkey Milk Alpha-Lactalbumin: Nutritional Component, Not a Biomarker

Alpha-lactalbumin in donkey milk is not a biomarker for any disease or physiological condition. Instead, it is a nutritional protein that plays a crucial role in lactose synthesis and provides bioactive properties that may influence digestion, immune function, and gut health. 

While alpha-lactalbumin has been studied for its structural similarities to human milk proteins, it does not serve as a diagnostic marker for milk allergies, intolerances, or any other medical condition.

Potential Health Benefits of Donkey Milk

Donkey milk provides a hypoallergenic alternative to cow milk with lower beta-lactoglobulin levels, immune-boosting bioactive peptides, high lactose content aiding calcium absorption, and a rich supply of water-soluble vitamins (B-complex and vitamin C), though it is lower in fat-soluble vitamins (A, D, E, and K).

When to Consider Donkey Milk as an Alternative

Donkey milk may be an option for some individuals with Cow Milk Protein Allergy (CMPA) under medical supervision, infants unable to tolerate breast milk or formula (with supplementation and under medical guidance only), those with mild digestive sensitivities (excluding lactose intolerance), and elderly or immune-compromised individuals seeking additional nutritional support.

Final Considerations

While donkey milk shows nutritional promise, its use as a widespread milk alternative is limited by availability, cost, and the need for supplementation to meet essential dietary needs. 

Research continues into its functional food applications, particularly in pediatric and geriatric nutrition. However, it should not be assumed to be a universally tolerated alternative, and allergy testing or medical guidance is recommended for individuals with a history of dairy allergies.