(The Gist of Science Reporter) All You Wanted to Know About Lactose Intolerance [JANUARY-2019]

(The Gist of Science Reporter) All You Wanted to Know About Lactose Intolerance

The fist nourishment a newborn receives is milk. In mammals, milk production originates in the mammary glands of the female, with which the mother suckles the young one.
Colostrum is the first milk produced soon after the baby is born. It contains dense nutrients like proteins, sugars (including lactose), water and is rich in antibodies to provide immunity to the baby.
Milk including that of humans contains a disaccharide called Lactose. This complex sugar in its nascent form is not readily absorbed in the body and hence needs to break down into simpler components. This breaking down is an enzymatic process involving the enzyme lactase-phlorizin hydrolase encoded as LCT and commonly known as Lactase. Lactase converts lactose to galactose and glucose which are easier to absorb.

Cow milk is the most widely used milk, while buffalo, goat, sheep, camel and yak milk too are consumed in different regions of the world.
Milk is mostly water with dissolved carbohydrates and has a pH of 6.4 to 6.8.
Lactose contributes to the sweetness of milk and the calorie content of milk.
Complex phospholipids make up the main fat composition of milk called Butterfat. These lipids also contain fat soluble vitamins like A, D, E and K along with essential fatty acids.
Casein is the chief protein constituent while water-soluble lactoglobulina make up the whey protein.
Milk is also a rich source of salts, vitamins A, B-group, C, D, K, E, thiamine, niacin, biotin, riboflavin, folates, and pantothenic acid and essential minerals like calcium, phosphate, magnesium, sodium, potassium, citrate, and chloride.

Intolerance to milk has been baffling scientists who until the sixties believed that the inability to assimilate milk was a deficiency disorder. They thought that those with this anomaly lacked lactase production in their body and hence developed the condition, naming it as Lactose Intolerance.
However, studies in the past few decades revealed startling results which called for an overhaul of understanding milk assimilation.

As seen, intolerance to milk could stem out of a natural process and should not be confused with an allergic reaction to specific dairy products. For example, allergy to cow’s milk is triggered by the immune system while intolerance is the result of the response of the digestive system.
In the case of LNP, the lactose remains undigested in the stomach and begins to decompose due to the action of gut bacteria. There is an increase in lactic acid, gas and fatty acids which can be easily detected.
Lactose intolerance can occur due to secondary reasons like an underlying medical condition such as celiac disease, irritable bowel syndrome, or intestinal infection. In such instances, the person is unable to digest milk until remedial action is taken for the cause. By eliminating the reason, lactase activity returns.
Very often intolerance to dairy is mistakenly self-diagnosed leading to nutritional deficiency. Determining lactose intolerance is best done by medical experts. Physicians usually ask:
To maintain a food diary.
To avoid lactose in the diet for a specified period and at the end of it reassess the symptoms.
For a fasting blood sugar test. Then, the person is given a glass of milk or a lactose solution. If there is no change in the blood sugar level, then it indicates LNP as lactose was not assimilated.
A few other determining tests like the hydrogen breath test, stool acidity test, and in rare cases invasive test such as a stool bowel biopsy.

Birds produce milk too! Some birds like pigeons, doves, flamingos and penguins have extended muscular pouches under their throats called crop. This bag-like addition is an extension of their oesophagus which plays a significant role in nestling young ones.
The crop produces a thick, cheese-like substance, which the bird regurgitates to feed their hatchlings.
The substance is called crop-milk and is high in proteins, fat, antibodies and antioxidants to nourish the young ones.
Just like in mammals, the hormone prolactin governs the production of crop-milk.
Crop-milk begins to produce a week before the eggs hatch. At this time the parent bird stops feeding to ensure the crop-milk is not contaminated by indigestible elements.
The hatchlings depend entirely on crop-milk for nourishment for about two weeks, by the end of which the little birds begin to slowly wean away from crop milk and survive on adult bird food.