Organic vs. Regular Milk: What's the Difference?

Studies show that organic milk has a slightly higher concentration of vitamin E, iron, and the polyunsaturated fatty acids omega-3 and omega-6. These nutrients are important for brain function, vision, and children’s growth and development (1, 3, 4, 5).

However, these differences may only be marginal and not offer more nutritional benefits than conventional milk (1, 4).

Other reviews suggest that farming practices that allow cows to graze and forage — rather than organic farming itself — may be responsible for the improved fatty acid content of organic milk (1, 3).

Furthermore, organic milk is lower in iodine and selenium, two nutrients that are important for thyroid health (1, 6).

Organic and conventional milk have similar levels of essential minerals, such as calcium, potassium, and sodium.

Conventional milk has slightly fewer calories and less saturated fat and protein than organic milk.

One cup (240 mL) of each type of milk contains:

Summary

Organic cow’s milk is higher in polyunsaturated fatty acids than conventional milk, although both have comparable levels of calcium, potassium, and sodium. Organic milk is lower in iodine and selenium and slightly higher in calories.

The U.S. Department of Agriculture’s (USDA) guidelines for organic dairy livestock prohibit the general use of antibiotics (9).

However, in emergencies — for example, if an animal’s life is in danger — a veterinarian may administer antibiotics. The use of antibiotics must be reported to the USDA, and the cow must be segregated and sold to a nonorganic farm (9).

Conventional dairy farms, on the other hand, use an array of antibiotics on cows. The medicine is often used to treat mastitis, an inflammation of the mammary glands (10, 11).

Antibiotics, such as beta-lactams, may then be found in the final milk product — albeit in safe levels, according to the U.S. Food and Drug Administration (FDA) (10, 11, 12, 13).

Drug residue refers to small amounts of drugs found in milk products after they’re used to treat animals during rearing. These can include antibiotics or growth hormones (10).

The FDA has established safe levels for drug residues in milk and meat. Drug residue levels above the FDA’s limit are illegal (10, 12).

A recent study found that, compared with regular milk, levels of antibiotics and pesticides in organic milk were undetectable (14).

This is partly because many medicines are banned on organic farms. Animals on these farms are often treated with alternative therapies, including botanicals, vitamin supplements, and homeopathic therapy (15).

Additionally, when approved drugs are used on organic farms, the farms must adhere to withdrawal periods. For instance, when a cow receives the opioid butorphanol, it cannot be slaughtered for meat for 42 days, and its milk must be discarded for 8 days (16).

Cows naturally produce bovine growth hormone — also called bovine somatotropin (bST) — to regulate milk production. Many conventional dairy farms administer a synthetic version to produce milk at a lower cost (14).

The FDA has determined that bST is safe for humans. The agency approved the use of bST under the trade name Posilac^TM in the 1990s (17).

This means that milk and meat from cows treated with Posilac^TM are safe for human consumption (17).

A recent study found that regular milk has higher levels of bST than organic milk (14).

Given that lactating cows naturally have high levels of bST and the natural and synthetic bST compounds are so similar, the FDA has not established a limit for the amount of bST in cow’s milk (10).

Organic cow’s milk lasts longer than regular milk — 40–60 days unopened compared with 15–17 days for conventional milk — due to ultra-high temperature processing (UHT) (18).

Typically, pasteurizing cow’s milk involves heating it to 161° F (71.7° C) for 15 seconds. This process protects the vitamins and organic compounds in milk (18, 19).

UHT, on the other hand, heats milk to 280° F (137.8° C) for 2 seconds and offers greater protection against bacterial growth. That’s important on organic farms, as the cows do not take antibiotics (18).

Not all organic milk will undergo UHT, so shelf life may vary among organic dairy products (18).

Summary

Regular milk has higher — albeit safe — levels of drug residues, including antibiotics and growth hormones, than organic milk. Organic milk has a longer shelf life due to the pasteurization processes it undergoes.

Consumers are conscious of the environmental impact of conventional farming and more likely to support farming practices that are sustainable for the environment (20, 21, 22).

Although long-term studies are scant, organic farming may be more environmentally friendly than conventional farming. It’s characterized by higher soil quality and lower nutrient losses (23, 24).

However, there is conflicting information regarding nitrous oxide, carbon, and ammonia emissions. Organic farms may produce higher levels of these emissions, but more research is needed (23, 24).

Regardless, organic milks come at a slightly higher price than regular options. A gallon of organic whole fat milk from Whole Foods costs $5.99, compared with $4.09 for a gallon of regular whole fat milk (25, 26).

Summary

Organic farming practices may have more positive environmental outcomes than conventional farming practices, but organic milk products often come with higher price tags.

Organic milk has a more desirable fatty acid composition than regular milk, although it’s lower in iodine and selenium — two nutrients essential to thyroid health.

It also has undetectable levels of antibiotics and growth hormone, likely due to a combination of alternative therapies, such as botanicals, vitamin supplements, and homeopathy.

Overall, organic milk has a nutritional profile similar to that of regular milk but lower levels of drug residues. Some studies also suggest that organic farming may be more sustainable for the environment, but more research is needed.