Milk is one of the most popular food items consumed worldwide. Milk products are used in many countries around the world including India, China, Japan, Mexico and other parts of Europe. Milk is a very important source of protein and carbohydrates for humans. Humans cannot produce their own insulin; instead they get it from foods such as milk or other dairy products (1). Milk provides energy and nutrients to the body which helps maintain normal growth, development, mental health and immune system function (2).
The human body needs carbohydrates to perform its functions properly. Carbohydrates provide fuel for the brain, muscles and other organs of the body. When there is not enough carbohydrate available in the diet, the body will turn to stored fat stores for energy (3). Milk contains high amounts of both glucose and fructose.
These sugars are broken down into simple sugars (glucose) and then absorbed into the bloodstream where they can be utilized by the body (4).
Glucose is a type of sugar that your body uses to make energy. Glucose enters the cells in two ways: through the action of enzymes called glycolysis and by using another molecule called glycogen. When there is a surplus of glucose in the blood, the excess gets converted to glycogen and stored in the liver and muscles for future use (5). If there is a drop in blood sugar levels, such as after a high-intensity workout or when you haven’t eaten in a while, glycogen is broken down, releasing glucose into the bloodstream so that your cells have the energy they need.
Your cells then utilize this glucose to do their job (6).
Fructose is another type of sugar found in many fruits, vegetables and in some root crops. Fructose gets absorbed by the intestines into the bloodstream more quickly than glucose but it doesn’t trigger the release of insulin (3). Because of this, large amounts of fructose can affect blood sugar levels leading to an increase in fat production and storage. Fructose has a tendency to turn to fat more quickly than other types of sugars.
Even though milk contains much less fructose than the amount found in fruit, it is still not a good idea to over consume it (4).
The liver is the organ that processes and metabolizes the sugars in milk. When you drink products containing milk, the liver has to instantly produce more of the enzymes needed to handle the sudden increase in sugar. The liver can only process a limited amount of sugars at any given time. If the liver is busy processing sugars from milk, it won’t be able to process other foods that you eat (4).
In addition to the sugar in milk, there is another substance known as galactose. Galactose is a type of sugar that doesn’t get metabolized or utilized by the body in any way. Milk contains a combination of both glucose and galactose. When both sugars enter the liver at the same time, they can cause oxidative stress within the organ.
The oxidative stress weakens the liver cell membranes, making them prone to damage and death. The death of liver cells can lead to a condition known as fatty liver disease (7).
The gastrointestinal tract is lined with small hairs and cells known as exocrine glands. These act together to help break down food so that it can easily be absorbed into the body. When you consume milk and its sugar, changes start occurring in these cells. The cells develop unnatural holes in them and they lose their ability to contract and expand.
This leads to a decreased ability to absorb nutrients, but an increased ability to absorb fat (3).
The digestive system is crucial for the body’s ability to get energy from food. When the digestive system doesn’t work properly, all aspects of the body suffer. Consuming milk and its sugars can cause stomach problems and contribute to chronic diarrhea.
Sources & references used in this article:
Consumer risk perception and recombinant bovine growth hormone: The case for labeling dairy products made from untreated herd milk by RN Mayer, DL Scammon… – Journal of Public Policy …, 1995 – journals.sagepub.com
Understanding the dairy cow by G Taubes – 2008 – Anchor
Baby Food Matters: What science says about how to give your child healthy eating habits for life by J Webster – 2020 – books.google.com
Dairy Pros and Cons by C Llewellyn, H Syrad – 2018 – books.google.com