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Milk contains essential vitamins and minerals and provides a number of health benefits as part of a nutritious diet. Humans have been drinking cow’s milk throughout history, with studies tracing consumption back to the Middle Neolithic period, around 6,000 years ago. But drinking milk can also have harmful effects for some people.
Cow’s milk is not suitable 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 out of 22 essential nutrients, so it is often recommended as part of a balanced diet.
The Nutrients in Milk
According to the United States Department of Agriculture (USDA), there are:
Calories
The amount of calories per serving of milk depends on its fat content. Eight ounces of full-fat milk has 146 calories compared to 83.6 calories in non-fat. Milk is a good source of energy.
Carbohydrates
The lactose in milk makes it a rich source of carbohydrates. The body breaks these down into glucose (blood sugar), which it converts into energy. Some dairy products have added sugars, increasing their carb content.
Protein
Milk also contains high levels of 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 faster. The other 80% is casein protein, an insoluble protein. Dairy protein contains all nine essential amino acids, which help with protein, neurotransmitters (brain chemicals), and hormone production.
Fats
Milk is categorized by fat content, so it’s easy to determine which type will have more or less of this nutrient. Full-fat milk has 7.8 g per 8 oz, while non-fat milk has only trace amounts. About 70% fat is saturated (which can build up in your bloodstream when consumed in excess), and the rest is unsaturated.
Vitamins and Minerals
Milk is a significant source of several essential vitamins and minerals, including:
Benefits of Milk
There’s a reason you remember public health campaigns encouraging people to drink milk. Researchers have found that dairy consumption offers numerous health benefits.
Appetite Control
Studies suggest that milk’s high protein, lactose and fat content keeps you full longer and may help control appetite. In a 2018 study of obese children, full-fat milk was found to suppress hunger for up to four hours.
Bone Development
Milk contains many vitamins and minerals essential for bone formation and growth, including protein, calcium, phosphorus, magnesium, manganese, and zinc, as well as vitamins D and K. In children and adolescents, dairy intake is linked in studies to healthier bone development.
High in Protein
Milk is a rich source of protein, containing about 8 g per one-cup (8-ounce) serving. This leads to a number of health benefits, including:
- Bone density: Researchers found that protein interacts with other minerals in milk to preserve bone density as adults age.
- Healthy teeth: Containing 80% of dairy protein content, casein can protect your teeth, and studies have linked milk consumption in children with fewer cavities.
- Muscle development: Milk protein can also help build and maintain muscles; the 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 found that nutrients in milk, including phosphorus, vitamin D, calcium, magnesium, and protein, play a role in bone development for both children and teenagers. Some evidence also shows that it helps adults in this regard as well.
Milk and Smiles
There is significant evidence that drinking milk promotes dental health. Milk’s calcium and phosphate content helps teeth maintain strength and protect them from cavities.
Heart Health
The relationship between milk consumption and heart health is complex, with both positive and negative effects. Several studies have consistently linked low-fat, high-calcium dairy products to lowering blood pressure. This reduces the risk of hypertension (high blood pressure), protecting the body from heart issues and stroke (dangerous interruption of blood flow in the brain).
Prevention and Management of Diabetes
In several ways, drinking milk can help the body fight diabetes, a chronic inability to metabolize sugar effectively. Studies have found that high dairy consumption reduces the chance of developing childhood obesity (overweight), a significant risk factor for diabetes. In addition, researchers have noted that drinking milk on a calorie-restricted diet can help facilitate weight loss, which helps manage diabetes.
The Negative Side Effects of Milk
Although drinking milk can have many positive health effects, there may also be disadvantages. Some people are allergic or intolerant to dairy. Dairy consumption is also linked to certain conditions.
Acne
Acne (acne vulgaris) occurs when hair follicles are plugged up with oil or dead skin, and causes pimples or bumps on the skin. In a wide-ranging review of data from more than 78,000 children and adults aged 7-30, drinking dairy – drinking milk and eating cheese – increased the risk of breakouts. Researchers aren’t sure why this happens but believe an inflammatory (immune) response to dairy may be to blame.
Other Skin Conditions
High dairy consumption is also associated with inflammatory skin conditions. In some people, dairy consumption may trigger attacks of eczema (titchy, flaky) and rosacea (red, flushed skin). Even among those without a complete allergy, researchers have noted that consumption can cause this response.
allergies
Researchers estimate that up to 3% of toddlers and infants under the age of 3 have some form of milk allergy. This decreases with time, and 80% of children with milk allergies become allergic by the age of 16. These allergies develop as dairy triggers inflammatory responses. An allergic reaction to exhaustion can cause:
- Hives or bumps developing on the skin
- Stomach ache
- Vomiting and nausea
- Bloody stool
- Anaphylaxis (a rare and serious systemic shock that causes breathing difficulties)
Lactose intolerance
Up to 68% of people have lactose malabsorption and lactose intolerance. These are problems with digestion and the breakdown of lactose (milk sugar). Lactose intolerance can cause bloating, nausea, diarrhea, gas, abdominal pain, stomach grumbling, and vomiting.
Bone Fracture
Although milk consumption is involved in the development and maintenance of bones, it may increase the risk of breaking your bones. In a large-scale study that evaluated data from over 100,000 participants, researchers found that increased intake in women aged 39 to 79 years resulted in a higher incidence of bone fractures.
Cancers
The evidence regarding milk consumption and cancers is mixed, and some studies have found it to be protective against colorectal cancer. In some 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 more studies are needed to confirm this.
Heart disease
Although dairy intake has been linked to reducing high blood pressure and boosting heart health, there may also be negative side effects. Full-fat milk can cause spikes in low-density lipoprotein (LDL, or “bad”) cholesterol, which increases the risk of heart disease. However, studies have not consistently linked increased dairy consumption to this issue.
How Much Milk Should You Drink a Day?
To prevent milk allergy or lactose intolerance, most nutritional 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 servings for children aged 9–18 years
- Up to 2.5 servings for toddlers and infants under 2
However, all this comes with some controversy. Citing possible links to disease and the disproportionate intolerance of lactose among non-white populations, the American Medical Association (AMA) urged the USDA to revise these guidelines and make it clear that dairy is optional.
Who Should Avoid Cow’s Milk?
As much as dairy products can be part of a nutritious diet, they are not right for everyone. Those with milk allergies or showing signs of milk allergies – especially infants and young children – should avoid milk. Another reason to avoid dairy products is lactose intolerance. Compared to White people, this issue is more common among African Americans, Native Americans, Asian Americans, and Hispanic Americans.
Talk to a health care provider if you or your child is experiencing digestive symptoms or hives after drinking milk. They can determine if you have lactose intolerance or a dairy allergy.
Alternatives to Cow’s Milk
If cow’s milk isn’t a good choice for you, there are plenty of plant-based alternatives. These come from four different sources:
- Grain milk such as oat or rice milk
- Legume milk, such as soy or pea milk
- Similar to almond milk, cashew, and coconut milk
- Seed-based milk, such as hemp or flax milk
However, it is important to remember that the nutritional content of soy, almond, oat, and other dairy options varies and may not be the same as milk. Of 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 milk’s nutrition facts label. Look for alternatives that are high in protein and low in saturated fat and do not contain added sugars or saturated fat. If you’re on a diet, be aware that some plant-based milks have more calories than low-fat or skimmed milk.
Summary
Although not suitable for everyone, milk can be a healthy, nutritious part of your diet. Dairy products are rich in essential vitamins and minerals and are good sources of protein, offering many health benefits. However, some people are allergic to milk or lactose intolerant, and consuming milk can lead to specific health problems. Other plant-based alternatives, such as soya milk, may not have the same nutritional content as milk. Talk to a health care provider about whether to include milk in your diet.
