This video from Dr. John McDougall provides a clear explanation of how and why dairy products are thought to trigger type 1 diabetes in children and young adults, in addition to allergies, asthma, and other autoimmune diseases.

Mothers’ milk is species specific: the composition of each animal’s milk has evolved over millions of years to perfectly meet the unique nutritional needs of the young of that species exclusively. Since a calf doubles its birth weight nearly four times faster than a human infant does, the concentration of protein in cows’ milk is 3 to 4 times higher than that found in human breast milk, and whereas breast milk contains just the right ratio of fatty acids, lactose, vitamins and amino acids for human digestion, brain development, and growth, cows’ milk contains these things in concentrations designed to turn an 80-pound calf into an 800-pound cow by 1 year of age. Because human bodies are not designed to consume it, cows’ milk is a major cause of childhood allergies, asthma, ear infections, skin rashes, and a host of other maladies; causes premature cholesterol build-up in arteries, the main precursor to heart disease; and is consistently linked to several cancers and other serious illnesses later in life.

Dairy consumption not only causes completely unnecessary suffering and death for millions of cows every year in the U.S. alone, but it’s also harmful for the humans who consume it. Ditching dairy doesn’t have to be difficult; for tips on tons of delicious plant-based milks, creams, cheeses, yogurts and more, check out our Guide to Going Dairy Free. For a look at peer-reviewed scientific studies that highlight the link between cows’ milk consumption and incidence of type 1 diabetes in children, see the following summaries:

Nutritional factors and worldwide incidence of childhood type 1 diabetes.

Early introduction of dairy products associated with increased risk of IDDM in Finnish children.

Early exposure to cows’ milk raises risk of diabetes in high risk children



Cow’s milk exposure and type I diabetes mellitus. A critical overview of the clinical literature.

Cow’s milk diabetes evidence mounts.

Ischaemic heart disease, Type 1 diabetes, and cow milk A1 beta-casein.

Learn more about the many harms of dairy at our Dairy Facts page.