Nutritional value of milk & Facts

nutritional value of milk:

Milk is an essential part of our food culture. Milk is a fluid which is made up of almost 88 % water and the remaining 11 to 12 % consists of all the other constituents. It performs the role of an essential beverage which supplies macronutrients and many micronutrients.

Milk is also used to make several other products such as cream, butter, curd/yogurt, ghee, kefir and cheese which are consumed all over the world. Before we know the nutritional value of milk, let’s explore the different components present:

Composition of milk

The major component of milk is water which is about 88 %. Milk also contains protein 3.15 %, lipids 3.25 % and carbohydrates 4.8 % (1). nutritional value of milk is high owing to it being a good source of several minerals such as calcium, phosphorous and vitamins like vitamin A, vitamin D, choline and vitamin B₁₂.

nutritional value of milk:

Protein in milk

Like all the other animal source proteins milk protein is also a complete protein that is it has all the essential amino acids required by us. Milk contains two major proteins casein and whey. Casein accounts for 80 % of milk protein and whey accounts for about 20 % of milk protein (2).

Milk is good quality and complete protein source. Milk proteins are known not only for their nutritional value of milk but also for their biological properties (2).

Lipids in milk

Milk has 3.25 % fats. 1.8 % is saturated fatty acids, 0.2 % polyunsaturated fatty acids and 0.8 % monounsaturated fatty acids. nutritional value of milk has a good proportion of saturated fat. Milk also contains 10 mg of cholesterol in 100 ml of milk.

Carbohydrates in milk 

Milk has 4.8 % of carbohydrates. The carbohydrate present in milk is in the form of disaccharide lactose, adding to the nutritional value of milk.

Energy from milk

A cup of milk if it is 200 ml it gives 122 kcal. That is 100 ml milk has the calorific value of 61 kcals. The calorie value may change if the fat content is altered like making low fat or skim milk adding to the nutritional value of milk.

Minerals from milk

Milk 100 ml provides 113 mg of calcium, 84 mg phosphorous, 132 mg of potassium, 43 mg of sodium and 3.7 mg of selenium.

For bone health calcium and phosphorous are essential and milk provides both these elements. Calcium bioavailability from dairy products is quite good compared to plant sources (3).

Vitamins from milk

Vitamins present in milk are vitamin A 46 µg, vitamin D 1.3 µg, vitamin B₁₂ 0.45 µg and 14 mg of choline. Milk is a good source of vitamin A. It is one of the few sources of vitamin D and only source of vitamin B₁₂ for vegetarians.

Health facts & nutritional value of milk

Milk and body weight

From the results of a study it was seen that milk and milk products have a positive effect on abdominal obesity that is they contribute towards reduction of waist circumference which is a significant predictor of metabolic syndrome (4).

A diet containing milk and milk products reduces the risk of childhood obesity and dairy products also improve the body composition in adults. Overweight and obesity are risk factors for developing type 2 diabetes hence increase the nutritional value of milk (5).

In a meta-analysis of work done on dairy products and weight loss they concluded unless calories are restricted there is not much effect of dairy products on weight loss. And on restricted-calorie diet they have a modest effect on facilitating weight loss (6).

Milk may or may not help reduce weight as the results available till now are not consistent but it definitely is a good source of essential nutrients making the nutritional value of milk rich.

Milk and heart health

Saturated fat content of the diet is a major risk factor for heart problems. Milk fat major constituent is saturated fat. And milk also contains cholesterol, adding to the nutritional value of milk.

A literature review concluded that evidence indicates a higher consumption of milk and dairy products around 200 to 300 ml per day does not increase the risk of any cardiovascular disease. And the review also concluded that there is an inverse association with hypertension and stroke (5).

Milk and bone health

Milk is a good source of calcium and phosphorous both of which are required for strengthening bones. adding to nutritional value of milk. A review of the evidence suggested that there is a positive effect of milk and dairy products consumption on bone health during childhood and adolescence (5).

Milk and cancer

According to a review of literature milk and dairy products consumption may protect against certain types of cancers such as colorectal cancer, bladder cancer, gastric cancer, and breast cancer (5).

Lactose intolerance

Lactose intolerance is the inability of the body to metabolize lactose due to the lack of enzyme lactase in the digestive system. It could be congenital lactase deficiency in infants who cannot tolerate lactose due to the absence of the enzyme lactase in the intestinal mucosa.

In the absence of the enzyme, lactose cannot be hydrolysed to glucose and galactose and there is an accumulation of free lactose in the intestines that leads to abdominal discomfort.

Treatment of lactose intolerance may include taking a reduced amount of lactose and lactase enzyme replacement (7).

Final word on nutritional value of milk:

Milk and milk products are sources of some of the essential nutrients and at the same time have the ability to reduce the risk of some chronic diseases. There may be some people who may not be able to consume milk because of problems such as lactose intolerance but others only benefit from consuming milk.

Take milk in moderation as food that supplies many important nutrients and at the same time promotes our health given the nutritional value of milk. Incorporate milk and milk products into your balanced diet regularly.

References:

1. United States Department of Agriculture, USDA Food Composition Databases.
   https://ndb.nal.usda.gov/ndb/search/list

2. Davoodi, S. H., Shahbazi, R., Esmaeili, S., Sohrabvandi, S., Mortazavian, A., Jazayeri, S. and Taslimi, A. (2016) Health-Related Aspects of Milk Proteins, Iranian journal of pharmaceutical research: IJPR. Vol. 15(3).
   https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5149046/

3. Dairy nutrition. Calcium and Bioavailability
   https://www.dairynutrition.ca/nutrients-in-milk-products/calcium/calcium-and-bioavailability

4. Romaguera, D., Ängquist, L., Du, H., Jakobsen, M.U., Forouhi, N.G., Halkjær J, Feskens, E. J. M., Van der, D. L. A., Masala, G., Steffen, A., Palli, D., Wareham, N.J., Overvad, K., Tjønneland, A., Boeing, H., Riboli, E. and Sørensen, T.I. (2010) Dietary determinants of changes in waist circumference adjusted for body mass index – a proxy measure of visceral adiposity, PloS one. Vol. 5(7).
   https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2904387/

5. Thorning, T. K., Raben, A., Tholstrup, T., Soedamah-Muthu, S. S., Givens, I. and Astrup, A. (2016) Milk and dairy products: good or bad for human health? An assessment of the totality of scientific evidence, Food & nutrition research. Vol. 60.
   https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5122229/

6. Chen, M., Pan, A., Malik, V. S. and Hu, F. B. (2012) Effects of dairy intake on body weight and fat: a meta-analysis of randomized controlled trials, The American journal of clinical nutrition. Vol. 96(4).
   https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3441106/

7. Deng, Y., Misselwitz, B., Dai, N. and Fox, M. (2015) Lactose Intolerance in Adults: Biological Mechanism and Dietary Management, Nutrients. Vol.7 (9).
   https://www.ncbi.nlm.nih.gov/pubmed/26393648