Health Benefits Of Milk

Is milk healthy? There are many differing opinions and recommendations regarding dairy consumption. While previous advice has praised dairy consumption, many modern recommendations suggest limiting dairy intake and advise against excessive consumption.

Health benefits of milk

Milk consumption offers a wide range of health benefits. The health benefits of this nutrient-rich beverage vary depending on the type of cow’s milk. For example, full-fat milk contains more saturated fat and calories than skimmed milk. Detailed below are some health benefits of milk.

Strong bones and teeth

The most well-known health benefit of milk is that it helps to maintain strong and healthy bones and teeth.¹ The high protein and calcium contents of cow's milk are thought to be the two reasons why cow's milk is associated with higher bone density.² However, the evidence can be contradictory, with some studies not recognising the association between milk consumption and bone density.^3,4

Muscle and weight gain

Due to milk's high protein content, milk is excellent for muscle growth and the prevention of sarcopenia, which is the loss of muscle mass due to old age.⁵ Dairy products can also assist in weight management due to their high protein content, making them very filling. It is recommended that older adults consume 1.2 grams of protein per kilogram of body weight, while healthy young adults consume 0.75 grams of protein per kilogram of body weight.⁶

Heart health

One of the key health benefits of milk is the positive effect that milk can have on heart health. A study by the British Journal of Nutrition found that men who consumed fermented dairy products regularly had a lower risk of coronary disease than men who ate smaller quantities of these dairy products.⁷ Other studies have suggested similar recommendations to regularly consume fermented dairy products due to their positive impact on blood lipid levels.⁷ Dairy products have also been linked to reducing high blood pressure due to their potassium, calcium, and magnesium content and the formation of antihypertensive peptides during milk digestion.^8,9 However, the consumption of extremely large quantities of milk could be related to an increased risk of cardiovascular disease.¹⁰

Nutrients we can get from milk

There are numerous nutrients available in milk, which makes it a crucial component of a healthy diet. Milk is full of nutrients such as vitamin B12, potassium, phosphorus, riboflavin, niacin, vitamin D, calcium, magnesium, vitamin A, and zinc.^1,11 Many milk products are also fortified with vitamin D.¹²

Calcium

Milk is famously known to be an excellent source of calcium, which is an essential nutrient required for maintaining bone density.² Adults younger than 50 require 1000 mg of calcium each day, with women over 50 and men over 70 requiring up to 1200 mg each day.¹³ 

Fat

Milk is also high in fat. Whole milk has approximately 3.7% fat and contains roughly 400 types of fatty acids, with most of the fats being saturated fats.¹⁴ Fat-free and low-fat milk are still recommended to adults, however, full-fat milk does not seem to have a major impact on health. 

Carbohydrates

Milk contains approximately 5% carbohydrates in the form of the sugar lactose, which is then broken down into glucose and galactose. The glucose and galactose are absorbed into the bloodstream where galactose is converted into glucose by the liver.

Protein

Milk contains two types of proteins: casein and whey. Casein provides most of milk’s protein composition and is an insoluble milk protein.¹⁵ It has been found to increase mineral absorption of key nutrients such as phosphorus and calcium. Whey is a small component of milk and contains branched-chain amino acids that are key amino acids for the body.¹⁵ Whey offers numerous health benefits and has been found to reduce blood pressure and improve immunity.¹⁵ Whey and casein are often isolated, sold, and consumed as high-protein supplements. 

Hormones

Milk is also full of natural hormones that assist with growth and development. Insulin-like growth factor-1 is one hormone that has been found to have an impact on humans and assists with regeneration and growth.¹⁶ Another hormone found in small quantities is bovine growth hormone but that has been found to have no known effect on humans and is only biologically active in cows.

Ways to include milk in our diet

While milk can be enjoyed as a beverage by itself, many people are not fond of the taste or find it difficult to consume enough milk to get its health benefits. Fortunately, there are many ways to incorporate milk into your diet. Milk can be added to other beverages, for example, coffee and tea. Flavoured milk such as chocolate milk is a popular way to enjoy milk as a drink and is even recommended to athletes after exercise as a recovery drink to improve their time to exhaustion.

If cow’s milk isn’t an option, there are many different types of milk to try. Different types of milk will have differing fat, taste, and nutrient compositions. Goat milk is a popular alternative that has a tangier taste than cow's milk. 

Another option beyond drinking milk is to incorporate other dairy products such as cottage cheese, yoghurt, and cheese that can be easily included in balanced meals. Dairy products are often traditionally included in numerous delicious meals and can be easily added to basic snacks such as oatmeal or smoothies.

How much is enough?

Milk offers a wide range of health benefits but too much can have a negative impact on the body, particularly if you are lactose intolerant. Common symptoms of excessive dairy consumption are nausea, bloating, and acne. You should aim to drink milk in moderation to avoid any negative side effects.

Drinking raw, unpasteurised milk is particularly dangerous and can expose you to a plethora of harmful microorganisms. Milk is pasteurised to destroy any bacteria, yeasts, and moulds that are hazardous to human health.

Other potential negative impacts of milk are:

Acne 

Acne is a potential consequence of heavy dairy consumption, documented in multiple studies.¹⁷ Dairy products are known to contain growth and milk-production regulating hormones that can disrupt insulin regulation in people to trigger acne.¹⁶

Weight gain

Weight gain is another negative effect of excessive milk intake due to the high calories of full-fat dairy products. Weight gain can easily occur as people don't realise how many calories they're drinking as they usually don't feel full after a beverage. There are many low-fat alternative milk and dairy products that are lower-calorie alternatives for those focused on weight management.

Cancer

Large quantities of dairy have also been linked to certain forms of cancer, such as prostate or breast cancer. However, the scientific evidence is not conclusive, with another study finding dairy reduces the risk of other forms of cancer, such as colon cancer.¹⁸

Lactose Intolerance and Cow’s milk allergy

Lactose intolerance

Lactose intolerance is when people do not have the ability to digest lactose, the main carbohydrate in milk. Within a few hours of consuming dairy, it is common to experience diarrhoea, stomach cramps, flatulence, nausea, and severe bloating. Lactase enzyme is necessary to break down lactose into glucose and galactose, however, some people do not produce enough lactase. In this situation, lactose is not broken down and becomes fermented and produces gases and short-chain fatty acids.¹⁹ 

While 65% of adults have some type of lactose intolerance, it is especially common in those of African-Caribbean or Asian descent.¹⁹ A person's genetics has a large impact on the incidence of lactose intolerance. Approximately 65-95% of the populations in Asia, South America, and Africa are thought to have lactose intolerance. In comparison, only 5-15% of the European population is thought to have lactose intolerance.¹⁹ It is important to note that lactose intolerance can develop at any age.¹⁹

Milk allergy

It is also possible for people to have a milk allergy, which is more common in infants and children than adults.²⁰ This allergy, in most cases, is due to a reaction to casein and the whey proteins: beta-lactoglobulin and alpha-lactoglobulin.²⁰ The allergic reaction will lead to the person experiencing swelling, rash, breathing difficulties, and bloody stool.²⁰ It is advised to strictly eliminate milk and milk-containing food from the diet for cow’s milk allergy. 

While there is no cure for lactose intolerance, symptoms can be alleviated by reducing dairy consumption or using lactose substitutes. Those with lactose intolerance may find it difficult to consume the recommended minerals and vitamins that are found in large abundance in milk. 

Potential conditions caused by a lack of the key nutrients found in milk are as follows: 

• Malnutrition: With a lack of the necessary nutrients, it is easier to become malnourished, with wounds taking longer to heal, and experiencing fatigue and depression
• Osteoporosis: Bones become thinner and weaker, making you susceptible to fractures and breaks. The decrease in bone density can be a major risk for older adults.

Alternatives to milk

While milk can be used to create a wide range of dairy products such as yoghurt, butter, cheese, and cream, there are many ways to enjoy milk without consuming dairy. Soy milk is often recommended as it has the most similar protein content to dairy milk. However, these milk alternatives differ in their nutrient composition and may not offer the same health benefits as dairy milk. Other popular alternatives include oat milk, coconut milk, almond milk, and hemp milk. It is important to note that many of these milk alternatives are heavily processed and may contain added sugars and additives. Therefore, it is important to read their nutrition labels carefully.

Summary

Milk is a high-protein drink that contains a range of key nutrients including vitamins and minerals. It offers a wide range of health benefits including improving bone density and muscle mass and has a positive impact on heart health. However, despite these benefits, milk consumption has been linked to weight gain and acne, as well as having a severe impact on those with lactose intolerance. It is recommended to enjoy milk and other dairy products in moderation.