Some people, both diabetics and non-diabetics, are lactose-intolerant and/or have an allergy to casein, proteins commonly found in mammalian dairy products. Lactose intolerance can cause symptoms like gas, bloating, and diarrhea. Some lactose-intolerant diabetics, eat dietary vegan, with no dairy products.

References

Ratini, Melinda, DO, MS, reviewed by. “What is lactose intolerance?” WebMD (June 19, 2019). http://www.webmd.com/digestive-disorders/tc/lactose-intolerance-topic-overview#1 (accessed on 8/2/2020).

Felson, Sabrina, MD, reviewed by. “Casein Allergy Overview,” WebMD (June 12, 2020). https://www.webmd.com/allergies/casein-allergy-overview#1 (accessed on 8/2/2020).

Montgomery, Bridget. “The Dairy Connection: Type 2 Diabetes and Lactose,” The Diabetes Council (updated June 3, 2020). https://www.thediabetescouncil.com/the-dairy-connection-type-2-diabetes-and-lactose/ (accessed on 8/2/2020).

Welch, Mark E., AS, CPhT. “Diabetes and Lactose Intolerance,” The Diabetic Friend, n.d. http://www.thediabeticfriend.org/diabetes-and-lactose-intolerance/ (accessed on 8/2/2020).