Health-minded consumers are increasingly vocal about their basic right to know what's in their food -- and with good reason.

Case in point: synthetic hormones in milk. Fourteen years after a highly contentious Food and Drug Administration decision allowing milk and dairy products from cows injected with Monsanto's genetically engineered bovine growth hormone -- often called rBGH, also recombinant bovine somatotropin, or rBST -- the controversy continues.

As scientists and consumer advocates warned at the start, revving up cows with a synthetic hormone to force them to produce about 15 percent more milk is a terrible idea.

Recombinant bovine growth hormone is bad for cows, burning them out in three or four years, causing terrible stress and a long list of medical problems including reproductive complications, lameness, pus in the milk and higher rates of udder infections that are treated with powerful antibiotics.

Even more worrisome, rBGH is likely hazardous for humans because milk from injected cows contains significantly higher levels -- from 18 percent to 106 percent -- of a potent cancer-tumor promoter called insulinlike growth factor 1, or IGF-1.

A number of studies have indicated that people with higher levels of IGF-1 in their bodies suffer higher rates of colon and breast cancer. In addition, Monsanto's rBGH is also more immunogenic -- it stimulates the immune system more -- than the nongenetically engineered growth hormone produced naturally by a cow's pituitary gland.

Finally, rBGH is bad for family farmers because it artificially increases the supply of milk on the market, driving down prices paid to smaller farmers and giving large, intensive-confinement dairy farms a competitive advantage.

Since 1994, government officials have been aware that Americans are wary of rBGH and genetically engineered foods in general. Polls consistently show that 80 percent to 95 percent of consumers want mandatory labels on rBGH-derived dairy products -- mainly so they can avoid buying them.

Acknowledging significant concerns over rBGH-tainted milk, the FDA -- ignoring legal precedent -- declared in 1993 that it would not require labeling, thus keeping consumers in the dark.

In response, activists dumped rBGH-tainted milk outside supermarkets across the nation. Several hundred dairies declared that they would not use the drug and would label their products "rBGH-free," which the FDA reluctantly agreed would be allowed.

Beginning in the late 1990s, the controversy over rBGH spread globally. Europe, Canada, Japan, New Zealand, Australia and other industrialized nations banned the use of rBGH on animal- and human-health grounds and began requiring labels on genetically engineered foods.

Today, millions of health-minded consumers are buying organic or rBGH-free milk. Natural food stores sales are booming.

In response, major dairy processors such as Kraft and Dean Foods, supermarket chains such as Kroger, coffeehouses including Starbucks and restaurant chains such as Chipotle have begun requiring that their suppliers stop using rBGH.

As a result, only 17 percent of America's dairy cows are being injected with the drug. Monsanto's response to widespread consumer rejection of rBGH has been to lobby the federal government to allow rBGH and genetic engineering in organics -- and, more recently, to outlaw rBGH-free labels.

Rebuffed last year by the FDA and the Federal Trade Commission in its efforts to ban rBGH-free labels, Monsanto has now turned to lobbying state legislatures in Ohio, Pennsylvania and other states. But thousands of calls and e-mails from consumers have prompted state legislators to back off, most recently in Pennsylvania.

Consumers want to know what's in their food and will respond to truthful labels such as organic and rBGH-free by voting with their dollars for safe, natural and humanely raised products.

The final step to consumer satisfaction is requiring dairy producers to label all of their products that contain synthetic hormones such as rBGH.

Ronnie Cummins is the national director of the Organic Consumers Association. Readers may write him at OCA, 6771 S. Silver Hill Dr., Finland, Minn. 55603. Distributed by McClatchy-Tribune Information Services.