Milk is a widely consumed food in America. With the greater presence of organic food products in the supermarket aisles, should you be choosing organic milk? Learn more about the differences between organic milk and conventional milk from a registered dietitian.
The milk is poured into a ceramic jug into a glass on a natural background
Credit: Getty Images / krisanapong detraphiphat

The demand for organic food has increased over the years. More people choose organic food, such as organic milk, for various reasons, including health, the environment and animal welfare. In 2020, organic food sales soared to $56 billion in the United States, with organic dairy products as the second-largest organic food group behind organic produce. Organic milk, which at one point was made for specific groups of consumers, has gradually become a mainstream product.

So, what is the difference between organic milk and regular milk? Is organic milk better? Should you choose organic milk over conventional milk? Let's take a deep dive to explore their similarities and differences from an agricultural and nutritional perspective.

Organic Milk vs. Regular Milk: what's the difference?

Organic milk and regular (also known as conventional) milk have some similarities and differences. The stark difference between the two types of milk lies within the agricultural practices used in milk production.

In the U.S., conventional farmers may use pesticides to control the growth of weeds with their crops. Cattle farmers could also use synthetic bovine growth hormone, a Food and Drug Administration (FDA)-approved drug to increase milk production, and antibiotics to reduce the risk of infection in cattle when needed.

On the other hand, organic milk producers must abide by the USDA organic guidelines. According to the standards, cattle farmers who want to produce organic milk must manage their herd as organic at least one year before milk production. The cows must be fed with certified organic feed and are not allowed to be injected with growth hormones nor given antibiotics.

Is conventional milk safe to consume?

Because pesticides, synthetic growth hormones and antibiotics may be used in conventional milk production, residues of these substances could potentially be present in the milk sold to consumers. Some research studies suggest that dairy cows injected with synthetic growth hormones may raise humans' insulin-like growth-factor-1 level (IGF-1).

Under normal circumstances, IGF-1 is a growth hormone promoting bone and tissue growth and development. However, several studies noted that increased levels of IGF-1 might increase one's risk for colorectal, prostate and breast cancers and influence the growth and development in children.

Dairy cattle injected with synthetic growth hormones may also be more prone to infections, increasing their need for antibiotics, thereby raising conventional milk consumers' risk to greater exposure to antibiotics and antibiotics resistance.

While consuming conventional milk may pose some health risks for certain individuals, the evidence is mixed and more research is needed to determine their long-term health effects.

That said, conventional milk is still safe to consume. This is in large part thanks to the FDA, which sets limits on the amount of trace antibiotics that could be present. The FDA also works closely with the USDA's Food Safety and Inspection Service and state regulators to ensure unapproved and unsafe drugs are not used for milk production.

On the contrary, organic milk is free of pesticides, synthetic hormones and antibiotics due to the farming standards farmers adhered. You can also be assured that the organic milk you purchased is truly organic by seeing the USDA green and white certified organic symbol stated on the packaging.

Are there nutritional differences between conventional and organic milk?

Both conventional milk and organic milk provide 16 essential nutrients, including protein, calcium, phosphorus, vitamin A, vitamin B12 and vitamin D, making them highly nutritious. While both have similar nutrition profiles, some research studies suggest organic milk has higher fat levels, including omega-3 and polyunsaturated fats.

One study has found that two cups of organic full-fat milk consist of 14 mg more omega-3 fats than the conventional full-fat variety for the same amount of milk. This slightly higher amount of omega-3 fats present may be due to the feed provided by the farmers.

According to the same study, organic farmers offer more fresh forage to the cattle. Feeding the dairy cows with fresh forage may be one of the reasons for organic milk having a more favorable fatty acid composition than conventional milk. The season of the year of milk production may also contribute to the varying levels of fatty acid present between regular milk and organic milk, despite the type of farming method used.

Another possible difference between organic milk and conventional milk is the higher concentration of conjugated linoleic acid (CLA) present in the organic variety. CLA is a type of fat found in dairy and beef that may be associated with supporting a healthy immune system and reducing the risk of heart disease, cancer, obesity, osteoporosis.

So, is organic milk better for you? While there are some studies about the difference between organic and conventional milk, more research is needed to clarify their long-term effects on health. The greater amount of fatty acids present in organic milk is not convincing enough for the scientific community to recommend choosing organic milk over conventional milk. The overall nutritional profile is relatively similar between the two types of milk, resulting in the lack of concrete evidence to suggest that organic milk, and organic foods in general, are significantly more nutritious than their conventional counterparts.

Why does organic milk last longer?

While organic milk and regular milk have similar nutrition and serve the same purpose, organic milk last substantially longer than conventional milk. Organic milk undergoes a process called "ultra-pasteurization" where it is heated to 280°F for 2 seconds, rather than 161°F for 15 seconds like conventional milk. This allows it to last for 40 to 60 days after opening, compared to 15 to 17 days for conventional milk that is pasteurized at a lower temperature. So, if you run into problems with your milk going bad before you can finish it, organic milk might be something worth trying.

Should you choose organic versus conventional or vice versa?

What type of milk you choose is ultimately a personal choice. You may lean towards choosing organic food over its conventional counterparts for various reasons.

Conventional dairy farmers must follow strict regulations about what is given to their cows. However, if you are still highly concerned about being potentially exposed to trace amounts of pesticides, antibiotics, and synthetic growth hormones in conventional milk, you may want to consider organic milk.

Food products that are produced organically require a bigger time commitment and financial investment from the farmers and producers. That said, organic foods are generally pricier than conventional choices. If you are on a budget, conventional milk might be a better choice. Since milk is a nutritious and affordable food, choosing conventional milk is better than avoiding milk altogether if you can't justify buying organic.

From a registered dietitian's perspective, both conventional milk and organic milk are highly nutritious and can be a part of your diet.

Bottom Line

The main difference between organic and conventional milk is in the way that milk is produced. Both organic milk and conventional milk are nutritious, provide similar nutritional qualities and can be part of a healthy meal pattern. Whether you choose organic milk or conventional milk is a personal preference. While there are some studies about the difference between organic and conventional milk, more research is needed to clarify their long-term effects on health.