What Is Lactose

Lactose is a type of sugar found in mammal milk, and it's the reason that milk tastes sweet. Additionally, the sugar makes up 2% to 8% of the content of milk.

Lactose is a sugar that is made from glucose and galactose. Before the body can use sugar, it has to be broken down, and that is the job of the enzyme called lactase.

How The Body Digests Lactose

After consuming dairy products, the lactose then travels to the small intestines. The lactase then splits the lactose into glucose and galactose, in which the enzyme can now be absorbed into the blood stream.

The glucose and galactose each have their own roles in the body. Glucose is used for energy, while galactose is used as a part of structures like glycolipids and glycoproteins. The process of breaking down lactose smoothly happens with lactase and is hindered without it.

When do we start making lactase?

Even before we are born, we start making lactase. It can be found in fetal intestinal lining by the 8th week of gestation and is usually at its highest levels by 34 weeks.

Things change right after being born. Starting about one month after birth, levels of lactase may begin to decline. This is called lactase non-persistence. This phenomenon varies from person to person, but the decline continues for many from childhood into adulthood.

About 30% of the world’s population can continue to make lactase after weaning. Because of this, they can eat dairy foods into adulthood without issue.

What does the lactase enzyme do?

The lactase enzyme is controlled by LCT gene, and its function is to break the sugar lactose into its two components: glucose and galactose.

The LCT gene is controlled by the MCM6 gene. Because of this, some people have a variant of MCM6 which allows for lactose to be digested into adulthood, while others do not have this and lose the ability to digest lactose after weaning.

When undigested lactose is present in the intestine, it draws water in, moving to the large intestine (colon) in where it is fermented by intestinal bacteria. Symptoms can include abdominal pain, diarrhoea, and excessive intestinal gas.

What Is Lactose Intolerance?

Lactose intolerance is a condition in which the enzyme lactase is absent or present in insufficient quantities, making the digestion of lactose difficult. It is important to clarify that this is not an allergy, but a digestive issue that makes the consumption of dairy uncomfortable.

The most frequent iteration of this condition is referred to as hypomastia which is when the production of lactase diminishes after childhood. This tends to start between the ages of six or seven and progresses with age. It can also affect a significant amount of the elderly population, over the age of 65.

Remaining lactase levels can vary among different individuals and ethnic groups, However, even 50 percent of the lactase enzyme is often able to enough to assist the digestive process involving the consumption of dairy.

With the increased studies on digestive health, and the consumption of dairy alternatives, it can be seen in the market. GMI Research states that the lactose market within Japan will increase over the next 5 years at a rapid rate in correlation with the projected trends until 2032.

Types of Lactose Intolerance You Should Know

Congenital Lactose Intolerance

This is also genetic, but far rarer. Congenital lactose intolerance arises when both parents of a child have the same genetic defect in the LCT gene. Symptoms of the child appear immediately after their first exposure to milk, typically resulting in violent diarrhea.

As this child will permanently be unable to tolerate any lactose, they will not be able to breast feed, and will have to subsist only on lactose-free formulas. This is a lifelong condition, and the child will need to completely avoid all lactose in order to avoid severe dehydration, nutrient deficiencies, and growing short for their age.

Primary Lactose Intolerance

This is the most common of all types of lactose intolerance. This is a normal and natural condition of the human body, and is caused by the body decreasing lactase production over time. Many lactase deficiency cases exist all over the world, and developing them is carried on a genetic basis.

There is a genetic correlation to it, with this condition being connected to the LCT gene. People with the Genotype have extremely low lactase levels. In contrast, those with the TT genotype typically and will produce lactase over time. Therefore, those with the CT genotype typically fall between the two extremes.