When today's moms were kids, a tall glass of milk was considered the ultimate health drink. It still is, but now parents are looking for something extra: the "USDA organic" stamp. Many shoppers are switching to organic because they fear exposure to harmful chemicals and hormones—especially for their kids. "Children are particularly vulnerable because their immune systems, brains, and organs are still developing," says Aaron Bernstein, M.D., of the Center for Health and the Global Environment at the Harvard School of Public Health. He adds that though levels of these substances in conventional milk may be within accepted limits, we don't have good answers yet about how repeated small exposures to hormone-like substances in milk and soy, along with chemicals like bisphenol A in plastics, add up over time. Due in part to these concerns, sales of organic dairy products have grown from $1.15 billion in 2002 to $4.57 billion in 2012—a 300% increase. But with an average price of $7 per gallon ($2.54 more than nonorganic), is it worth the extra bite out of your grocery budget?
What makes milk organic?
It's all about how the cows are fed and treated: They must graze in pastures and can never be injected with growth hormones or fed antibiotics, which conventional farms often give cows to promote growth and milk production. The cows must also be fed an organic diet, rather than conventional feed, which often contains genetically modified corn and soy, points out John Robbins, founder of Food Revolution Network.
Is organic more nutritious?
Organic and conventional milk provide equal boosts of vitamin D, potassium, and calcium, says Bernstein. Studies generally show that organic milk contains more heart-healthy omega-3 fatty acids than conventional milk—important for children's developing brains—and may contain less saturated fat. Those differences can vary from herd to herd, however, based on things like where the cows grazed and when they were milked.
What are people's worries about conventional milk?
Bovine growth hormone: Some nonorganic dairies give their animals the growth hormone rBGH. There's been concern that this hormone may be linked to the rising rates of early puberty in girls, but Bernstein points out that rBGH works only in cows—humans don't even have the hormone receptors it requires to boost growth. And pasteurization destroys 90% of any growth hormone left in the milk, while the acid in your stomach breaks down the rest. Hormones frequently cause cows to develop mastitis, however, says Robbins, requiring them to be given antibiotics.
Antibiotics: Cows raised on conventional farms are more likely to harbor antibiotic-resistant staphylococcus and salmonella bacteria compared with cattle on organic farms. These bacteria are not hiding in the milk in your supermarket—pasteurization kills them off—but buying organic milk does help support farmers who don't use antibiotics at all. And that matters, because if antibiotics lose their power to kill bacteria, simple childhood maladies like strep throat could become much harder to cure.
Pesticide residue: The toxic chemicals farmers use to kill pests can linger in food, but that's more likely in produce than milk, says Bernstein. While a 2008 USDA analysis found potentially worrisome levels of the pesticide residue DDE in both conventional and organic milk, more recent tests found pesticides in only 0.5% of the samples tested.
What's right for you?
Milk is healthy for you and your child; organic and conventional offer similar nutrition, and there's no strong evidence that hormones given to cows on conventional farms will cause harm. But organic farming is better for the animals and the earth, and if you're concerned about the overall effect of toxins in your child's environment and yours, serving organic milk is one way to buy some peace of mind.
"Raw milk" advocates claim that pasteurization neutralizes important proteins and enzymes—and leads to asthma, allergies, and lactose intolerance. They prefer to drink milk the way it comes out of the cow. But know the risks: Skipping pasteurization can expose drinkers to life-threatening infections from pathogens like E. coli and campylobacter. In fact, the Centers for Disease Control and Prevention estimates that you're 150 times more likely to get sick from raw milk than from pasteurized milk; in December the American Academy of Pediatrics issued a statement warning parents against serving it to their children.
This story originally appeared in the March/April 2014 issue of Dr. Oz The Good Life.