Milk has always been considered ideal food for infants and children and a good supplementary food for adults.  There can not be any substitute for milk.  What is a balanced diet?  Balanced diet is defined as one which contains a variety of foods in such quantities & proportions that the n maintaining health vitality & general well being & also makes a small provision for extra nutrients to withstand short duration of leanness. 

Milk is a fine blend of all the nutrients necessary for growth and development of young once, it’s a good source of protein fats sugar vitamins and minerals. 

Cows milk is an integral part of balanced diet due to following reasons:- 

1. Availability: 

Dietary pattern varies widely in different parts of world depending upon socio economic status, customs, taboos etc. but milk surpasses all these barriers as it is the only food widely available and acceptable. 

2. Nutritive value: 

Lets compare the nutritive value of cows milk and buffaloes milk.  All values are per 100 ml of milk 

CALORIES AND PROTEINS: 

Cow’s milk provides 67kcl and buffalo milk provides 117kcl of energy per 100 ml.  The protein content of cows and buffalo milk is about 3.2gm and 4.25gm per 100ml respectively.  The milk proteins mainly consist of casein (about 80%) and whey (about 20%).  The proteins of milk are of a high biological value.  This low content of protein cows milk from buffalo milk makes it ideal for infants and people with renal disorders.  Milk proteins have excellent nutritional quality in terms of their constituent amino acids. 

The use of milk proteins as nutritional supplements to enhance dietary protein quality is very feasible as they can provide lysine and tryptophan, the limiting amino acids of wheat and maize proteins. 

FAT CONTENT 

Cow’s milk contains practically half the fat content of buffalo milk.  This reduces the risk of coronary heart diseases.  Milk Fat – It’s Good for You!  Parodi (1997) succinctly summarized the contribution of cow’s milk fat components as potential anticarcinogenic agents.  The best-characterized anticarcinogenic agent presently is conjugated.  Iinoleic acid- In mouse models, dietary CLA has been shown to protect against the induction end proliferation of chemically-induced skin, for estomach, colon, prostate and mammary tumors.  CLA has drawn a great deal of attention among dairy, medical and nutrition scientists, other components of milk fat also have biological effects with anti-cancer properties.  Among these, sphingomeyelin, a component of the milk fat globule membrane, and thus particularly rich in buttermilk, contains the biologically-active components ceramide and sphingosine CLA fed before puberty may impart long-lasting protection against induction and proliferation of tumors. 

Research suggests that CLA can decrease the amount of fat in the blood the amount stored in the body. 

These effects coculd help in the fight against two other major killers, heart disease and obesity. 

CARBOHYDRATES 

The main sugar present in milk is lactose.  It is less sweet than cane sugar.  Lactose favours the absorption of calcium and phosphorous and the synthesis of some B complex vitamins in the small intestine. 

VITAMINS 

Milk has got valuable amounts of vitamin A, thiamine, riboflavin and nicotinic acid but is a poor source of vitamin C and E.  It also contain vitamin 812 which is absent in vegetarian food items.  Cows milk has more carotene than buffaloes milk.  It is very important for vision.  FOLIC ACID PREVENTS ANEAMIA AND NEURAL TUBE DEFECTS IN NEWBORN.  A distinct advantage of cows milk over human milk is that it’s a better source of vitamin K which prevents hemorrhagic disease of newborn. 

MINERALS 

The important minerals of milk are calcium, phosphorous, sodium and potassium.  It is a poor source of iron.  Less phosphorous content of cows milk allows better absorption of calcium.  It is a good source of zinc which is required for synthesis of insulin by the pancreas and for immunity function.  While calcium has been the main nutrient of interest in relation to milk and milk products and their effects on bone growth there is also the possibility that other nutrients which are found in milk may be important.  Energy and protein modulate bone growth and micro nutrients such as zinc may also have an effect.  The form of calcium salt may also be important.  It has been prposed that the calcium phosphate in milk may have different mechanistic effects on bone compared to other calcium salts. 

Studies show that milk and products may decrease the risk of osteoporosis through their effects on growth. 

WATER 

Milk contains about 85% water.  It thus supplies both food and fluid.
 

VARIOUS FORMS IN WHICH MILK CAN BE CONSUMED 

Unfermented Products: 

Skimmed milk is deficient in fats and fat soluble vitamins but the protein, sugar, minerals and vitamin B factors (except pyrodoxine) are well preserved.  If skimmed milk power is supplemented with vitamin A, D and pyri doxine, it is a comparatively cheap food of high nutritive value.  It is useful for the treatment of malnutrition, the nephritic syndrome and the cirrhosis of liver.  The addition of about 6 tablespoons of skimmed milk power during the preparation of chapattis, custard, curd, etc will supply an additional 35 gms of protein. 

Toned milk: This is prepared by mixing equal parts of fresh buffalo milk (rich in fats) and reconstituted skimmed milk power.  The fat, protein, carbohydrate, vitamin and mineral contents – and thus the nutritive value – are the same as fresh cow’s milk.  It is a useful source of proteins for malnourished children and pregnant women. 

Double toned milk contains only 1.5% fat. 

Khoa (Mava) is milk in which the water content is reduced to between 20% and 25%.  It is prepared by vigorously boiling milk, and stirring it continuously to avoid burning at the bottom or overflowing at the top.  When cooled, khoa forms a uniform mass, containing fats, heat-coagulated proteins and lactose.  Khoa supplies 82 kcal (344 KJ) per table spoon. 

Chhana (cottage cheese) is prepared by adding lemon juice to boiling milk; this precipitates casein, lactalbumin and fat.  The liquid part (whey) is strained through a cloth and chhana is collected. 

Whey is a byproduct of butter and cheese production and is frequently discarded.  However, when dried it can be preserved, and forms a good source of nutrition in poorer countries. 

Fermented Products: 

Dahi (Curd)  The mode of preparation of dahi varies considerably, as does its flavour.  The flavour depends upon the type of lactic acid organisms predominant in the starter.  It has same calorie value as that of milk from which it has been prepared. 

Yoghurt is the name given to milk cuddled by a specific type of lactic acid bacillus called Lactobacillus bulgaricus.  

Lassi (Butter milk) When dahi is churned with water and fat is removed, the residual acid buttermilk is called lassi.  Dahi and lassi can be prepared from whole or skimmed milk. 

Ghee (Clarifled butter: Butter-fat)  The composition of cow and buffalo ghee is similar: 99% fat, mostly saturated; about 1114 microgms (3800 iu) vitamin A per 100 gms, varying with the exposure of cattle to the sunshine. 

Cheese Cottage cheese is an unfermented milk product, but cheese produced commercially in the west is a fermented product.  There are over 400 varieties of cheese. 

MYTHS ABOUT MILK:- 

IS MILK PROTEIN, CASEIN, DIFFICULT TO DIGEST? 

When cow’s milk is heated (as in pasteurization), homogenized or acidified to produce a softer curd, the protein is used by infants as efficiently as is the protein of human milk. 

IS MILK FAT DIFFICULT TO DIGEST?

Milk fat is considered to be the most complex of all of the common fats and exhibits unique physical, chemical and biological properties not easily duplicated by other fats.  It is though that this arrangement contributes to the ease of digestibility of milk fat compared with other fats.

To summarize cows milk is best source nutrition and every effort must be made to channelise the available milk to vulnerable groups like young infants   preschool children, pregnant and lactating women.

Dietician

Guru Nanak Eye Centre, New Delhi.