回复: 关于牛奶有危害的说法是谣言
Bovine growth hormone supplementation
Since November 1993, with FDA approval,[108] Monsanto has been selling recombinant bovine somatotropin (rbST), also called rBGH, to dairy farmers. Cows produce bovine growth hormone naturally, but some producers administer an additional recombinant version of BGH which is produced through a genetically engineered E. coli because it increases milk production. Bovine growth hormone also stimulates liver production of insulin-like growth factor 1 (IGF1). Monsanto has stated that both of these compounds are harmless given the levels found in milk and the effects of pasteurization.[109]
On June 9, 2006, the largest milk processor in the world and the two largest supermarkets in the United States – Dean Foods, Wal-Mart, and Kroger – announced that they are "on a nationwide search for rBGH-free milk."[110] Milk from cows given rBST may be sold in the United States, and the FDA stated that no significant difference has been shown between milk derived from rBST-treated and that from non-rBST-treated cows.[111] Milk that advertises that it comes from cows not treated with rBST, is required to state this finding on its label.
Cows receiving rBGH supplements may more frequently contract an udder infection known as mastitis.[112] Problems with mastitis have led to Canada, Australia, New Zealand, and Japan banning milk from rBST treated cows. Mastitis, among other diseases, may be responsible for the fact that levels of white blood cells in milk vary naturally.[113][114]
rBGH is also banned in the European Union.[115]
Criticism
Vegans and some other vegetarians do not consume milk for reasons mostly related to animal rights and environmental concerns. They may object to features of dairy farming including the necessity of keeping dairy cows pregnant, the killing of almost all the male offspring of dairy cows (either by disposal soon after birth, for veal production, or for beef), the routine separation of mother and calf soon after birth, other perceived inhumane treatment of dairy cattle, and culling of cows after their productive lives.[116]
Some have criticized the American government's promotion of Milk consumption. The United States government administers the popular Got Milk? and milk mustache advertising campaigns, which cost roughly $180 million per year and make the milk industry millions of dollars. The main concern is the financial interest that the American government has taken in the dairy industry, promoting milk as the best source of calcium. All United States schools that are a part of the federally funded National School Lunch Act are required by the federal government to provide milk for all students. The Office of Dietary Supplements recommends that healthy adults between ages 19 and 50 get about 1,000 mg of calcium per day,[117] but studies show that the human body can only retain about 550 mg of calcium per day. Milk also contains more excess calories, sugar, and fat than many other sources of calcium.
There is also some skepticism of the idea that large doses of calcium provide for healthier bones and teeth. This is a commonly held belief, but there have been some studies that show there is "no connection between the intake of calcium (in any form) and the reduced risk of bone fractures in women aged 34-71 years".[118] Another study suggests that calcium supplements do not contribute to bone gain when you surpass a daily intake of 800 mg.
Varieties and brands
