Mammary glands in mammals produce milk, which is highly nutritious and can be used to nourish newborns for the first few months of their lives.
This article is about cow’s milk.
Many food products made from cow’s dairy include cream, butter, cheese and yogurt.
These foods are known as dairy products or milk products, and they are an important part of modern diet.
This article will tell you everything you need about cow’s milk.
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Milk’s nutritional content is complex. It has almost every nutrient your body requires.
One cup (249.5 grams) whole cow’s milk containing 3.25% fat ( 1Trusted source)
- Calories: 152
- Water: 88%
- Protein: 8.14 grams
- Carbs 12 Grams
- Sugar: 12 Grams
- Fiber: 0.
- Fat 8 Grams
Milk is rich in protein – approximately one gram per fluid ounce (30mL) or 8.14 grams per cup (249g) ( 1Trusted Source).
Two groups can be made of proteins in milk based on how water soluble they are:
- Insoluble milk protein are known as casein.
- Soluble Milk Proteins are also known as whey protein.
Both milk proteins can be considered excellent quality because they contain high levels of essential amino acids. They are also easy to digest.
Casein is the main protein in milk, accounting for 80% of it.
It is actually a group of proteins with alpha-casein as the most common.
One of the most important properties of caseinis its ability to increase absorption of minerals such as calcium, phosphorous ( 2Trusted Source).
It can also lower blood pressure ( 3Trusted Source, 4Trusted Source).
Whey makes up 20% of milk’s protein content.
It is particularly rich in branched chain amino acids (BCAAs), such as leucine and isoleucine.
Whey proteins have been shown to have many health benefits. These include lower blood pressure and better mood during stressful times ( 5Trusted source).
Whey protein is great for building and maintaining muscle mass. Whey protein is a popular supplement for athletes and bodybuilders ( 6Trusted Source).
Whole milk straight from cows contains around 4% fat
Many countries base milk marketing primarily on its fat content. The United States has three types of milk: whole milk, reduced-fat milk, and low-fat milk.
Milk fat is one the most complex natural fats. It contains about 400 types of fatty acids ( 7Trusted Source).
saturated fats make up around 70% of whole milk’s fatty acid content.
The total fat content of polyunsaturated fats is only 2.3%.
The rest, or 28%, is made up of monounsaturated fats.
Dairy products also contain trans fats.
Contrary to transfats found in processed foods, milk trans fats (also called ruminant fats) are beneficial for your health.
Milk contains very little trans fats such as vaccenic and conjugated Linoleic acids (CLA). ( 7Trusted Source).
CLA has received a lot of attention because of its potential health benefits. However, evidence is still lacking ( 8, 9Trusted Source and 10Trusted Source).
Some studies suggest that CLA supplements could harm metabolism ( 11, 12Trusted Source).
Carbs found in milk come mainly as simple sugar lactose ( 13Trusted source).
Your digestive system breaks down lactose into glucose and galactose. These substances are absorbed into the bloodstream where your liver converts galactose to glucose.
Some people do not have the enzyme necessary to break down lactose. This is known as lactose intolerance, which will be discussed later.
High-quality protein and other fats are excellent sources of milk. Around 5% of milk is made up of carbs. This is mainly because of lactose which some people are unable to digest.
Vitamins & minerals
All the vitamins and minerals needed to support growth and development of a young calf in its first month of life are found in milk.
It is also a good source of almost all the nutrients that are required by our bodies, making it one among the most nutritious foods.
These vitamins and minerals can be found in large quantities in milk.
- Vitamins B12 Only foods of animal origin contain this vital vitamin. Milk has a high level of B12 ( 1Trusted Source, 14Trusted Source).
- Calcium. Dairy is one of the most nutritious sources of calcium. 15Trusted source
- Riboflavin. Dairy products make up the largest source of riboflavin, also known as vitamin A2, in the Western diet ( 16TrustedSource).
- Phosphorus. Dairy products can be a good source phosphorus. This mineral plays an important role in many biological processes.
Sometimes, vitamin D is added to the diet.
Fortification refers to the addition of vitamins or minerals to food products.
Fortifying milk products in vitamin E is a common public health strategy ( 17Trusted source).
The daily value of vitamin D-fortified milk in the United States may be 12%. ( 18Trusted source, 19Trusted source).
Milk is a good source of vitamin B12 and other minerals like calcium, riboflavin and phosphorous. Milk is often supplemented with vitamin D and other vitamins.
There are more than 50 hormones that are naturally found in cow’s milk. These hormones are vital for the development and growth of a newborn calf ( 20).
Except for insulin-like growth factor-1, (IGF-1), no known effects of cow milk hormones on humans have been observed.
IGF-1 can also be found in breast milk. It is the only hormone that has been proven to be absorbed from cows’ milk. It is involved in growth and renewal ( 21Trusted source).
Bovine growth hormone, another hormone found naturally in milk in small amounts, is also present in small quantities. It is only biologically active in cows, and does not have any effect on people.
There are many hormones in milk that support the development of the newborn calves. One of these hormones, insulin-like growth factors 1 (IGF-1), has potential health consequences for people.
Health benefits from milk
Milk is one of your most nutritious foods.
It has been extensively studied and appears to offer many important health benefits.
Particularly, cow’s milk can positively impact your bones and blood pressure.
Bone health, osteoporosis
Osteoporosis is a condition that causes a decline in bone density and is the leading risk factor for fractures among older adults ( 22).
One function of cow’s milk in young calves is to encourage bone growth.
Cow’s milk appears to have similar effects on people ( 15Trusted source). This effect is believed to be due to the high calcium and protein levels in milk ( 23Trusted source, 24-Trusted source).
Recent evidence is contradictory. However, some studies have not shown a link between dairy intake and osteoporosis ( 25, 26,Trusted Source and 27TrustedSource).
High blood pressure is a risk factor for developing heart disease.
A lower risk of high blood pressure has been shown to be linked to dairy products ( 28Trusted source, 29Trusted source).
This effect is thought to be due to the unique combination of calcium and potassium as well as magnesium in milk ( 30Trusted source, 31Trusted source).
Other factors could also be important, like peptides formed during casein digestion ( 3Trusted source, 4Trusted source).
Milk, a rich source calcium, may increase bone mineral density and reduce your risk of developing osteoporosis. Reduced blood pressure has also been linked with milk and its products.
Possible adverse effects
Complex health effects of milk can be found — some components may have beneficial effects, while others could cause harm.
The main carbohydrate in milk is lactose or milk sugar.
It is broken down into its components — glucose and galactose – in your digestive system.
Some people may not be able to digest lactose properly after childhood, a condition called lactose intolerance.
A staggering 75% of the world’s population is lactose-intolerant, but the percentage varies depending on the genetic makeup ( 32).
Most people are affected by lactose intolerance in Asia, Africa, South America. It is estimated that 65-95% of the population has it ( 33Trusted source).
The prevalence in Europe is estimated to be between 5-15%. Northern Europe is the most affected ( 33Trusted source).
People with lactose intolerance may not absorb all of the lactose. Some or all of the lactose passes down to their colons, where bacteria begin fermenting it.
This fermentation process results in the formation of short-chain fat acids (SCFAs), and gas such as methane or carbon dioxide.
Many unpleasant symptoms of lactose intolerance include gas, bloating and abdominal cramps.
It is uncommon for adults to have milk allergy, but it is more common in children younger than 35 ( 34Trusted source).
Although allergic reactions are most often caused by alpha-lactoglobulin or beta-lactoglobulin in the whey protein, they can also occur due to caseins ( 35Trusted Source ).
Milk allergy symptoms include skin rash, swelling and breathing problems.
Milk consumption has been linked with acne — a common skin condition characterised by pimples on the back, face, and chest ( 37TrustedSource, 38TrustedSource, 39TrustedSource).
Consuming high amounts of milk is known to raise insulin-like growth factor-1 levels (IGF-1), which is thought to play a role in acne. ( 39Trusted source, 40Trusted source and 41Trusted source).
Milk and cancer
Numerous observational studies have examined the relationship between milk consumption and the risk of developing cancer.
The evidence is mixed and it’s difficult to draw any conclusions from it.
A fair amount of research has shown that men who consume dairy may be at greater risk for prostate cancer ( 42Trusted source, 43Trusted source).
Numerous studies have shown a link between dairy intake and lower colorectal cancer risk ( 44Trusted source, 45Trusted source, 46Trusted source).
It is a good idea to avoid excessive milk consumption. Moderation is the key.
Nearly all the milk sold for human use is processed in some manner.
This is done in order to improve the shelf life and safety of milk products.
Pasteurization refers to heating milk to kill potentially harmful bacteria found in raw milk ( 47Trusted Source).
Heat destroys both beneficial and harmful bacteria, yeasts, as well as molds.
Pasteurization doesn’t make milk sterile. To prevent any bacteria from multiplying, the milk must be quickly cooled after heating.
Pasteurization can cause a slight loss in vitamins from their heat sensitivity, but it doesn’t have any significant effect on milk’s nutritional values ( 48).
Milk fat is composed of many particles or globules of various sizes.
These fat globules in raw milk have a tendency not to stick to each other and float to surface.
Homogenization refers to the breaking down of fat globules in smaller units.
This is accomplished by heating the milk, then pumping it through narrow pipes at high tension.
Homogenization is used to prolong the shelf life of milk, give it a richer flavor and make it whiter.
Most milk products are made from homogenized milk. cheese is an exception, as it is often made from unhomogenized milk.
The effects of homogenization on nutrition quality are not harmful ( 49Trusted source).
Pasteurized milk vs. Raw
Raw milk refers to milk that has not yet been pasteurized.
Pasteurization refers to heating milk to extend shelf life and reduce the risk of infection from harmful microorganisms found in raw milk.
Heating can cause a slight drop in vitamins but it is not harmful for your health ( 50 51TrustedSource, 52).
Homogenization, which is the process of breaking down fat globules found in milk into smaller units, has no known adverse effects on health ( 49Trusted source).
Raw milk consumption is associated with lower rates of allergies, asthma, and eczema in children. This association is not fully understood ( 53Trusted source).
Raw milk is safer than processed milk.
Milk does not contain bacteria in healthy cows. The milk becomes contaminated by bacteria either from the cow or the environment during the processing of milking, transport or storage.
These bacteria are generally harmless and may even be beneficial. However, occasionally milk can become contaminated with bacteria that could cause disease.
Even though the risk of becoming ill from raw milk consumption is low, one milk-borne illness could have severe consequences.
Most people are quick to heal, but people with weak immune systems (e.g. older adults or very young kids) are more vulnerable to serious illness.
Public health advocates are unanimous in their belief that raw milk has no health benefits and could pose health risks due to contamination by harmful bacteria ( 54).
The bottom line
Milk is one the most nutritious beverages in the world.
It is rich in high-quality proteins and an excellent source for vitamins and minerals like calcium and vitamin B12 as well as riboflavin.
It may also reduce your risk of developing osteoporosis or blood pressure.
Some people may be allergic to milk proteins, or intotolerant to milk sugar (lactose). A link between milk and acne, as well as an increased risk for prostate cancer, has been established.
Moderate consumption of cow’s dairy milk is good for the majority of people, but it should not be consumed in excess.