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Introduction to Lactose

Lactose is a disaccharide sugar which is slightly-sweet and is found in milk and dairy. It is made up of 2 monosaccharides, naming glucose sugar and galactose. Lactose can be broken down into monosaccharides by the use of the enzyme lactase, which is produced in the digestive tract in humans. When the lactose is broken down, it can be absorbed into the bloodstream from the small intestine.

Lactose is made from whey which is a waste product in the cheese-making process. As lactose is really cheap, it is used in a lot of ways and products in the food industry. Lactose brings a bit of pleasant sweetness when added to products. So Commercial bakers sprinkle some lactose on the tops of bread and other foods to do caramelization. It adds both taste and texture to foods without affecting the primary flavor of the food.

It is also used in the medical industry as thousands of prescribed medications have lactose in them as a part of their formulations. Medicines are bitter, so to balance out the bitterness, a tiny amount of lactose is added to them.Human milk contains about 7.5 g per 100 mL of lactose, whereas, in cow's milk and other mammalian milk, the ratio of lactose is about 5 g per 100 ml. During infancy, lactose also plays a role in the absorption of calcium and other minerals such as copper and zinc.

What is lactose intolerance?

Lactose or dairy intolerance is the inability of the body to break down a type of natural sugar called lactose.

During the digestion process, the lactose in milk and dairy products is broken down into glucose and galactose for proper absorption. This process occurs in the small intestine by an enzyme known as Lactase. People who inherently have or develop a shortage of lactase are therefore unable to properly digest all or some of the lactose they consume. The unabsorbed lactose then goes into the colon where it causes various problems for our body.

How many People are Lactose Intolerant?

The exact number of humans with lactose intolerance is unknown, but one estimation puts the average at 65% of the global population to be lactose intolerant. The Rates of lactose-intolerant people vary between regions, ranging from less than 10% in Northern Europe to around 95% in parts of Asia and Africa.

How can you Develop Lactose Intolerance?

As we have already discussed above that lactose intolerance could be by birth, or it may happen at any time. There are three types of lactose intolerance a person may have:


  • Secondary Lactose Intolerance:


It develops when the production of lactase decreases in the small intestine due to any injury, surgery, or illness that involves the small intestine. The diseases related to this kind of lactose intolerance are bacterial overgrowth, Acute Gastroenteritis, celiac disease, Cohn’s disease, Cancer, and Chemotherapy. By getting treatment for the causal disorder, it can restore the lactase levels and improve health.


  • Primary Lactose Intolerance:


The most common way to develop lactose intolerance is called primary lactose intolerance. People who develop primary lactose intolerance get it from a natural and gradual decrease in lactase activity after stopping. In primary lactose intolerance, the production of lactase declines below normal at some point in life, and the reasons for it are unclear. The Symptoms might develop as early as 5, and can worsen with age. Some people may face a complete loss of lactase, but, most people almost retain 10-30% of their initial level of the lactase activity.


  • Congenital or Developmental Lactose Intolerance


In the above two cases, the lactose intolerance occurs later in life, but there are rare cases when babies are born with lactose intolerance caused by a complete absence of lactase enzyme. This usually happens when the disorder is passed from generation to generation. This is called autosomal recessive. Some kids who are born prematurely may also have lactose intolerance due to insufficient lactase level.

Lactose Intolerance Symptoms

The symptoms widely vary from person to person, as it depends upon how much he or she is lactose intolerant. It can range from mild, to uncomfortable and to severe. The most common indications of lactose intolerance are:

  • Nausea
  • Diarrhea
  • Flatulence or gas
  • Abdominal Pain
  • Abdominal Cramps
  • Intestinal Bloating
  • Borborygmi (gurgling or rumbling sounds in the stomach)

Dairy intolerance symptoms can typically emerge from about 30 minutes to 2 hours after ingesting foods containing lactose.

How to Tell if You are Lactose Intolerant?

A most straightforward method to check either you are lactose intolerant or not is called the milk challenge. Simply, drink a glass of milk after consuming any type of dairy products for several days, if you experience the symptoms mentioned above, you are likely to have the condition.

But before reaching any conclusion, visit a doctor. As a doctor has several tests to check if you are lactose intolerant or not, these tests include:

  • Genetic analysis
  • Intestinal biopsy
  • Stool acidity test
  • Hydrogen breath test
  • Lactose intolerance blood test

Lactose Intolerance can Develop at Any Age

Lactose intolerance is not a disease; it’s just a type of allergy that can develop at any age. Some kids are born with lactose intolerance, and many people become lactose intolerant later in life. This may be caused due to another medical condition, such as Cohn’s disease or sometimes it develops without any specific underlying cause.

Lactose Intolerance Treatment

If your doctor confirms you that you are lactose intolerant, there are several things you can do to control lactose intolerance.

The first step is to know which foods and drinks contain lactose. It is preferred to ask a nutritionist about it. The second step is when you purchase food items, try to pay attention to food labels or ingredients written at the packs. Food label lists will tell you all of the ingredients in order of the amount. So, you can decide either you should have it or not.

Another way is to plan your food by starting with small portions of dairy foods and gradually increase it over time. In this way, you will be able to figure out how much lactose your body can handle. Also, try to combine dairy foods with non-dairy foods. Because it will slow the release of lactose into the body and will make it easier for your body to breakdown the lactose.

Most importantly eat dairy foods that are naturally lower in lactose. For example, cheese and yogurt have less lactose than milk. Specifically, aged cheeses like parmesan, swiss, and brie tend to have low lactose. 

Lactose-Containing Foods

Apart from milk and all its types, including evaporated and condensed, there are many other foods that commonly contain lactose. For example, butter, heavy or light, whipping and sour creams, whey, cheese, and its types, yogurt, sherbet, ice cream, and kefir. The amount of lactose varies among these products, which makes some products more tolerant or intolerant than others.

Other than dairy or milk-based products, many processed foods also contain lactose in them like, bread and baked goods, store brought mixes of pancakes, biscuits and cakes, snack food and candies, cereals and margarine, frozen dinners and instant soups, dressings and creamy sauces.

Make sure to check the ingredient list before you eat. Remember that some non-dairy products can contain milk derivatives, most popular is sodium casein-ate, which may have low levels of lactose.

The Lactose Intolerant Diet

It is imperative to make sure you maintain a nutritionally well-balanced diet. As milk contains various vital nutrients that include calcium, protein, and vitamins A, B12, and D. So, it is crucial to make sure to supplement your diet with foods enriched with these nutrients. Because lactose free-diet can cause you to develop osteoporosis later in life.

To sustain healthy bones, children and adults approximately require 1000 to 1300 milligrams of calcium depending on age and gender. There are several "lactose-free" products that are good sources of calcium and vitamin D. These includes Soy, rice, almond, coconut milk, Collard greens, Kale, Broccoli, Spinach, Sardines, Fatty fishes like tuna, mackerel, and salmon, fish liver oil and Calcium-fortified orange juice, etc.

If you’re not sure either you are getting enough nutrients, then visit a dietician. He will plan the diet according to your level of intolerance to lactose. Also, dietary supplements can help you to get the standard recommended amount of nutrients.

Other Names for This Condition

There are other names that are also associated with lactose intolerance. Such as:

    • Alactasia
    • Hypolactasia
    • Lactose malabsorption
    • Milk sugar intolerance
    • Dairy product intolerance
    • Dairy intolerance


  • Milk and other dairy products have a sugar called lactose.
  • To digest lactose, our body contains an enzyme called lactase.
  • A lot of us don't have enough of this lactase enzyme in our body, which makes us lactose intolerant.
  • When we use milk and consume dairy products, it leads to bloating, flatulence, nausea, etc.
  • So, use Lactose-free dairy products. They have lactase in them that break down lactose for you.