Is Cow’s Milk Good for You? Pros and Cons of Drinking Cow’s Milk

People have been drinking cow’s milk for the past 8,500 years—even before many of us developed the gene to properly digest it—making it a dietary staple in many countries and cultures around the world.^1,2

What used to be undisputed as a healthy beverage has now come under scrutiny, with many debates trying to answer the question, “Is cow’s milk good for you?” 

Keep reading to learn more about the pros and cons of drinking milk, including a look at the different types of cow’s milk you might consume and their nutritional qualities. 

Cow’s Milk Nutrition

Choosing what type of milk you’re going to add to your morning coffee or cereal is no longer as simple as just grabbing a gallon off the shelf.

In addition to the myriad plant-based milk alternatives lining the shelves, we also have plenty of choices in cow’s milk alone, including non-fat, 1%, 2%, whole, organic, grass-fed, lactose-free, A2, and (in some areas) raw milk. 

Nutritional differences arise between non-fat, low-fat (1%, meaning 1% of its total weight is milkfat), reduced-fat (2%), and whole milk (3.25%), which we’ll highlight here, including some of the prominent micronutrients found in milk.

*Based on an 8oz (1-cup) serving

Additionally, milk from grass-fed cows provides omega-3 fatty acids and conjugated linoleic acid (CLA)—two healthy fats linked to heart and metabolic health. Each 100-gram serving (about 3.5oz) of grass-fed whole milk provides 50mg of omega-3s, compared to 20mg in conventional milk.³

Pros of Cow’s Milk

1. Nutrient-Dense

As far as beverages go, milk is about as nutrient-dense as you can get, containing 8 grams of protein per cup, several micronutrients (vitamins A, D, B12, calcium, phosphorus, and zinc), and, in the case of grass-fed milk, omega-3 fatty acids and CLA. 

Whole milk contains natural vitamin A in the form of retinol, while reduced-fat milk has synthetic vitamin A added back in after the retinol-containing fat is removed. Most types of milk (of all fat levels) in the United States are fortified with vitamin D.

2. May Support Bone Health

Cow’s milk contains about 300mg of calcium per cup. The RDA (Recommended Dietary Allowance) for calcium ranges from 1,000-1,300mg per day, depending on age and sex, meaning that a cup of milk provides 23-30% of your daily needs for calcium. 

Calcium is well-known for its role in supporting healthy bones, but milk also has other nutrients that help our bones, including phosphorus, vitamin D, and protein. 

Calcium and phosphorus combine into hydroxyapatite crystals that form and strengthen bones, while we need vitamin D to absorb calcium properly. Without enough dietary calcium, your body will take it from your bones to use in other, more important places (like the heart, muscles, and nerves), leading to a decline in bone density and, eventually, osteoporosis. 

One study found that bone mineral content was reduced by 5.6% in 20-49-year-old women who consumed less than one serving of milk weekly during childhood compared to women who drank more than one serving.⁴

Another showed that men, but not women, who consumed more milk and dairy products had increased bone mineral density in their spines.⁵

That said, not all studies support the theory that drinking milk reduces the risk of bone fractures or osteoporosis (despite what the pervasive “Got Milk?” Ads of the 1990s told us).⁶ 

3. Dental Health

Like bones, calcium and phosphorus are also needed to remineralize tooth enamel, supporting better dental health and stronger teeth. 

Casein—one of the main proteins in milk—also helps our teeth by forming a protective film on them, protecting them from acids produced by bacteria in the mouth.

Multiple studies have shown that children who drink more regular milk (not chocolate milk!) have a reduced risk of dental caries (cavities).⁷

4. Increased Satiety

Due to its balanced macronutrient profile, whole milk is satiating and can help with appetite control. 

A meta-analysis of 13 clinical trials found that consuming more than 500mL of dairy had significantly increased satiety (feelings of fullness after eating).⁸

Skim or non-fat milk does not appear to have the same satiating effects. One study of schoolchildren with obesity (aged 10-12) found that those who drank whole milk had decreased appetite and increased satiety compared to those drinking skim milk or apple juice. However, caloric intake at the next meal was not affected.⁹

5. May Help With Weight Management

Although the research is far from conclusive, some studies show that drinking milk can help with weight management. Interestingly, whole or full-fat dairy is more often associated with healthier body weights. This may be because of the satiating nature of the fats in whole milk. A meta-analysis of 42 studies showed that each 200-gram/day increase in milk consumption or total dairy intake reduced the risk of overweight or obesity by 12% and 25%, respectively.¹⁰

6. May Help Heart Health

Milk may also benefit heart and vascular health, likely due to the minerals calcium, potassium, and magnesium that help regulate blood pressure.

In the previously mentioned meta-analysis of 42 studies, each 200-g/day increase in milk was associated with a 6% reduction in rates of hypertension.¹⁰

It’s been previously thought that the higher saturated fat content of whole milk negatively impacts cardiovascular disease. However, recent research has shown that milk (full-fat or otherwise) has a neutral relationship with heart disease, meaning it neither increases nor decreases its risk—despite its saturated fat content.¹¹

Downsides of Cow’s Milk

Many ethical and environmental issues are associated with dairy farming, but we’re just going to talk about potential health consequences here. 

1. Lactose Intolerance and Allergies

One of the most widespread downsides of dairy milk is the fact that 68% of the population cannot properly digest it.¹² 

All humans can digest milk in infancy due to the presence of the enzyme lactase (which breaks down lactose, the sugar in milk). However, the adult’s ability to digest milk is a relatively recent evolutionary adaptation (in the grand scheme of human life).

About 6,000 years ago, pastoral cultures herded and domesticated animals like cows, sheep, or goats—and, as a result, developed lactase persistence that allows for the lactase gene to remain through adulthood to digest milk.

But, not all cultures were pastoral societies, meaning that many areas of the world did not evolve to digest milk in adulthood.

The main cultures that have lactase persistence are found in Northern Europe, some regions of Africa, some regions of South Asia, and the Middle East. Populations that are known to have higher rates of lactose intolerance include those of East Asian, West African, Arab, Jewish, Greek, and Italian descent.

Milk allergies are also prevalent, with an allergy to cow’s milk being the most common food allergy in young children. Many children can outgrow a milk allergy, but adults can also be diagnosed later in life.

2. Linked to Acne and Eczema

Dairy products are one of the most well-known foods associated with acne. This is because milk contains IGF-1 (insulin-like growth factor), a protein that increases sebum (oil) production in the skin. IGF-1 also stimulates keratin production in the skin (“hyperkeratinization”), which causes a buildup of keratin in the hair follicle on the skin and clogs pores. 

While IGF-1 is a beneficial growth factor for children and teens, it can also lead to breakouts when elevated in acne-prone people. 

One study involving over 78,000 adolescents, teenagers, and young adults found that drinking any type of milk increased the odds of having acne by 28%. When comparing fat levels, whole milk increased the odds by 22%, and low-fat or skim milk increased the odds by 32%.¹³

The researchers also looked at the frequency of milk consumption. Compared to those drinking milk rarely, the odds of acne increased by 24% for those drinking 2-4 glasses per week, 41% for drinking 1 glass per day, and 43% for those drinking over 2 daily glasses. 

Milk intake may also trigger symptoms of other skin conditions, including eczema and rosacea. 

3. Linked to Increased Risk of Certain Cancers

Dairy milk consumption has been found to increase the risk of some types of cancer. A meta-analysis of 34 studies showed that cow’s milk consumption was linked to an increased risk of ovarian cancer by 32%, prostate cancer by 23%, and liver cancer by 13%.¹⁴

The consumption of whole-fat milk but not low-fat milk was associated with increased cancer mortality—especially in females. However, fermented milk consumption (like kefir) reduced cancer mortality risk. 

According to the National Breast Cancer Foundation, there is limited evidence that links milk intake to breast cancer, although studies are not conclusive.¹⁵

One reason for these associations may be the IGF-1 content in milk. As a growth hormone, IGF-1 may also promote the growth of cancer cells. 

However, other research has shown that dairy consumption reduces the risk of breast and colorectal cancers. Overall, more research is needed on the link between milk and cancer.^16,17

The Bottom Line

Moderate cow’s milk consumption is likely healthy for most people—unless you are allergic or intolerant to it, that is. The available research suggests that milk may support bone and tooth strength, satiety and weight management, and possibly aspects of heart health. However, dairy milk is also linked to acne and other skin conditions and an increased risk of certain cancers.

In my opinion, as a Registered Dietitian, if you want to consume cow’s milk, the healthiest type is organic, grass-fed, full-fat cow’s milk from a dairy farm that promotes the ethical and humane treatment of cows. If you have issues with acne or skin health or experience digestive, joint, or inflammatory issues from drinking milk, consider switching to plant-based milk alternatives.

Is Cow’s Milk Good for You? FAQs