Critics of the United Kingdom's school milk program are becoming more vocal, challenging the widespread national assumption that drinking milk is good for children.

"From Winston Churchill's wartime order to keep the milk flowing, which was formalized under the 1946 School Milk Act ... the idea that it is natural, healthy and an essential part of a good diet has been unchallenged," writes Andrew Marszal in The Telegraph.

That consensus is wavering. Recently, junior health minister Anne Milton suggested that the national program to provide free milk for children under five should abolished. And research continues to emerge that milk is neither an essential nor healthy part of the human diet.

As Marszal notes, milk contains no nutrient that cannot be found in a balanced, dairy-free diet. Although milk is high in calcium, most of this nutrient cannot actually be absorbed by the human body, making green leafy vegetables a much more effective source. Cow milk, designed for calves, also contains more fat and protein than the human body needs -- which is unsurprising considering that while it takes a human infant 180 days to double its birth weight, it takes a newborn cow only 47 days.

Much of the concern over milk comes from the hormones and antibiotics inserted into it by modern factory farming. In the book Alternative Cures, author Bill Gottlieb quotes cancer specialist Elizabeth Ann Lowenthal as saying, "All dairy products, even those such as fat-free milk, contain potential tumor-promoting growth hormones that are fed to cows to improve their milk production."

Yet even organic milk has more than 30 proteins that can produce adverse reactions in the body, such that 7.5 percent of British children suffer from dairy allergies. Milk may also produce eczema, constipation, lingering ear infections and frequent colds. In addition, as many as 75 percent of adults may be lactose intolerant.

More recent research has also linked milk consumption to an increased risk of prostate cancer and both Type 1 and Type 2 diabetes.