Milk contains essential vitamins and minerals and provides several health benefits as part of a nutritious diet. Humans have drunk cow’s milk throughout history, with studies tracing its consumption back to the Middle Neolithic, about 6,000 years ago. But drinking milk can also have harmful effects for some people.
Cow’s milk is not ideal for everyone. This article explains the pros and cons of dairy in your diet and who should stick to dairy-free alternatives.
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Milk Nutrition Facts
Milk is rich in protein and contains 18 of the 22 essential nutrients, making it often recommended as part of a balanced diet.
The nutrients in milk
According to the United States Department of Agriculture (USDA), a glass of reduced-fat milk (2%) contains:
Calories
The amount of calories per serving of milk depends on the fat content. Eight ounces of whole milk contains 146 calories, compared to 83.6 calories in skim milk. Milk is a good source of energy.
Carbohydrates
The lactose in milk makes it a rich source of carbohydrates. The body breaks this down into glucose (blood sugar), which it converts into energy. Some dairy products have added sugars, which increases the carbohydrate content.
Egg white
Milk is also high in protein, making it a good source of this essential nutrient. About 20% of the protein in milk is whey, a soluble protein that the body digests more quickly. The remaining 80% is casein protein, an insoluble protein. Dairy protein contains all nine essential amino acids, which aid in the production of proteins, neurotransmitters (brain chemicals) and hormone production.
Fats
Milk is categorized by its fat content, so it’s easy to figure out which type will contain more or less of this nutrient. Whole milk contains 7.8 g per 8-ounce serving, while skim milk contains only trace amounts. About 70% is saturated fat (which can build up in your arteries if consumed in excess), and the rest is unsaturated.
Vitamins and minerals
Milk is an important source of several essential vitamins and minerals, including:
Benefits of milk
There’s a reason you may remember public health campaigns encouraging people to drink milk. Researchers have found that dairy consumption offers numerous health benefits.
Appetite control
Research shows that milk’s high protein, lactose and fat content keeps you full longer and can help control appetite. A 2018 study of obese children found that whole milk suppressed hunger for up to four hours.
Bone development
Milk contains many vitamins and minerals necessary for bone formation and growth, including protein, calcium, phosphorus, magnesium, manganese and zinc, as well as vitamins D and K. In children and adolescents, studies have linked dairy intake to healthier bone development .
Rich in proteins
Milk is a rich source of protein and contains approximately 8 grams per serving. This results in several health benefits, including:
- Bone density: Researchers found that proteins interact with other minerals in milk to maintain bone density as adults age.
- Healthy teeth: Casein, which makes up 80% of dairy’s protein content, can protect your teeth, and studies have linked milk consumption in children to fewer cavities.
- Muscle development: Milk protein can also help build and maintain muscle; researchers found that drinking milk after resistance training stimulates anabolism, the process of repairing and building muscle tissue.
Bone and dental health
There is something to the public health campaigns that linked milk to strong teeth and bones. Research has shown that nutrients in milk, including phosphorus, vitamin D, calcium, magnesium and protein, play a role in bone development in both children and adolescents. There is also some evidence that it helps adults in this regard too.
Milk and smile
There is considerable evidence that drinking milk promotes dental health. The calcium and phosphate content of milk helps teeth maintain strength and protects them from cavities.
Heart health
The relationship between milk consumption and heart health is complicated, with positive and negative effects. Some studies have consistently linked low-fat dairy products high in calcium to lower blood pressure. This reduces the risk of hypertension (high blood pressure) and protects the body against heart problems and strokes (a dangerous interruption of blood flow in the brain).
Diabetes prevention and management
In several ways, drinking milk can help the body fight diabetes, a chronic inability to metabolize sugar effectively. Research has shown that high dairy consumption reduces the risk of developing obesity in children (overweight), an important risk factor for diabetes. Additionally, researchers have noted that consuming milk during a calorie-restricted diet can help facilitate weight loss, which helps manage diabetes.
Negative side effects of milk
Although drinking milk can have many positive health consequences, it can also come with potential disadvantages. Some people are allergic or intolerant to dairy. Dairy consumption is also linked to certain conditions.
Acne
Acne (acne vulgaris) occurs when the hair follicles become clogged with oil or dead skin, causing pimples or bumps to form on the skin. An extensive overview of data from more than 78,000 children and adults aged 7 to 30 shows that consuming dairy (drinking milk and eating cheese) increases the risk of pimples. Researchers aren’t sure why this happens, but think an inflammatory (immune) response to dairy may be the cause.
Other skin conditions
High dairy consumption has also been linked to inflammatory skin conditions. In some people, consuming dairy can trigger attacks of eczema (itchy, flaky skin) and rosacea (red, red skin). Even in those who don’t have an outright allergy, researchers noted that consumption can trigger this reaction.
allergies
Researchers estimate that up to 3% of toddlers and infants under the age of 3 have some form of milk allergy. This decreases over time and 80% of children with a milk allergy outgrow it by the age of 16. These allergies occur because dairy triggers inflammatory responses. An allergic reaction to consuming can lead to:
- Hives or bumps that develop on the skin
- Stomach complaints
- Vomiting and nausea
- Bloody stools
- Anaphylaxis (a rare and severe systemic shock causing breathing difficulties)
Lactose intolerance
As many as 68% of people have lactose malabsorption and lactose intolerance. These are problems with digesting and breaking down lactose (milk sugar). Lactose intolerance can cause bloating, nausea, diarrhea, gas, abdominal pain, a growling stomach and vomiting.
Broken bones
Although milk consumption has been linked to bone development and maintenance, it can also increase the risk of bone fractures. In a comprehensive study that reviewed data from more than 100,000 participants, researchers found that increased intake in women between the ages of 39 and 79 led to a higher incidence of bone fractures.
Cancers
The evidence regarding milk consumption and cancer is mixed, with some studies finding it to be protective against colorectal cancer. In several studies, dairy intake increased the risk of prostate cancer in men and ovarian cancer in women. Researchers have also linked dairy consumption to an increased risk of breast cancer, although further research to confirm this remains necessary.
Heart disease
Although dairy intake has been linked to lowering high blood pressure and improving heart health, it can also cause negative side effects. Whole milk can cause spikes in low-density lipoprotein (LDL, or “bad”) cholesterol, which increases the risk of cardiovascular disease. However, studies have still not consistently linked increased dairy consumption to this problem.
How much milk should you drink per day?
Barring a milk allergy or lactose intolerance, most dietary guidelines recommend regularly including dairy in your diet. It is an excellent source of animal fats, calcium and vitamin D, among other nutrients. According to the USDA, the recommended daily amounts are:
- Three servings (3 cups milk or yogurt; 3 ounces cheese) for adults
- Three portions for children aged 9–18 years
- Maximum 2.5 servings for toddlers and babies under 2 years
However, all this brings with it some controversy. Citing possible links to disease and the disproportionate lactose intolerance among non-white populations, the American Medical Association (AMA) has urged the USDA to revise these guidelines to indicate that dairy is optional.
Who should avoid cow’s milk?
Although dairy products can be part of a nutritious diet, they are not suitable for everyone. Those who have milk allergies or exhibit symptoms of milk allergies – especially infants and toddlers – should avoid milk. Another reason to avoid dairy products is lactose intolerance. Compared to white people, this problem is more common among African Americans, Native Americans, Asian Americans, and Hispanic Americans.
Contact a healthcare provider if you or your child experience digestive upset or hives after drinking milk. They can determine whether you have lactose intolerance or a dairy allergy.
Alternatives to cow’s milk
If cow’s milk isn’t a good option for you, many plant-based alternatives exist. These come from four different sources:
- Grain milk such as oat or rice milk
- Legume milk, such as soy or pea milk
- Nut milks such as almond, cashew and coconut milk
- Seed-based milk, such as hemp or flax milk
However, it is important to remember that the nutritional value of soy, almond, oat and other dairy alternatives varies and may not match that of milk. Of all the possible types of milk, only soy milk fortified with calcium, vitamin D and vitamin A is considered comparable to dairy milk in the USDA dietary guidelines.
When choosing alternatives to cow’s milk, check the label for the milk’s nutritional content. Look for other options that are high in protein, low in saturated fats and do not contain added sugars or saturated fats. If you’re on a diet, keep in mind that some plant-based milks contain more calories than low-fat or low-fat milk.
Resume
While it’s not for everyone, milk can be a healthy and nutritious part of your diet. Rich in necessary vitamins and minerals, dairy products are good sources of protein and offer many health benefits. However, some people are allergic to milk or have lactose intolerance, and consuming milk can lead to specific health problems. Plant-based alternatives, such as soy milk, may not have the same nutritional value as milk. Talk to a healthcare provider about whether you should include milk in your diet.