In observational studies both across countries and within single populations, higher dairy intake has been linked to increased risk of prostate cancer (cited in [2]).

Observational cohort studies have shown higher dairy intake is linked to higher ovarian cancer risk (cited in [2]).

Cow’s milk protein may play a role in triggering type 1 diabetes through a process called molecular mimicry[3].

Across countries, populations that consume more dairy have higher rates of multiple sclerosis[4].

In interventional animal experiments and human studies, dairy protein has been shown to increase IGF-1 (Insulin-like Growth Factor-1) levels. Increased levels of IGF-1 has now been implicated in several cancers[5].

In interventional animal experiments[6] and human experiments[7], dairy protein has been shown to promote increased cholesterol levels (in the human studies and animal studies) and atherosclerosis (in the animal studies).

The primary milk protein (casein) promotes cancer initiated by a carcinogen in experimental animal studies[8].

D-galactose has been found to be pro-inflammatory and actually is given to create animal models of aging[1].

Higher milk intake is linked to acne[9].

Milk intake has been implicated in constipation[10] and ear infections (cited in [2]).

Milk is perhaps the most common self-reported food allergen in the world[11].

Much of the world’s population cannot adequately digest milk due to lactose intolerance.