Lactose tolerance in infants

Lactose is actually a disaccharide composed of glucose and galactose, but the human body cannot absorb lactose directly. Lactose needs to be diluted by lactase before the human body can absorb nutrients. Once the body lacks lactase and lactose is eaten at the same time, the lactose will not be diluted and will pass directly to the large intestine. The large intestine will be irritated, leading to symptoms such as diarrhea and stomach pain, collectively known as lactose intolerance.

Biological Principles

After weaning, mammalian babies begin to gradually reduce the synthesis of lactase. Human infants typically lose 90% of their ability to digest lactose by the age of four years[1], but this varies greatly from person to person. Some ethnic groups have a gene mutation on chromosome 2 that causes a reduction in the production of lactase, so these people can digest lactose throughout their lives.

There is no scientific consensus on when and where this variant appeared. Some people believe that it appeared independently in Sweden and the Arabian Peninsula around 4000 BC and gradually merged during the expansion, while others believe that it appeared in the Middle East around 4500 BC and then expanded to other places. Others believe that the mutation appeared independently at a later time among the Tutsi people in East Africa. The current situation is that most people of Western European ancestry have this mutation in their genes (meaning they can digest lactose throughout their lives), while most East Asians, sub-Saharan Africans, and indigenous peoples of the Americas and Oceania do not have this mutation (meaning they will become lactose intolerant in adulthood) [1]. On average, 75% of people worldwide experience symptoms by adulthood, so it is more appropriate to call it a natural condition rather than a disease.

People with lactose intolerance do not experience symptoms such as diarrhea immediately after ingesting a small amount of lactose, but only after ingesting more than a certain amount. So most people with lactose intolerance can still drink milk, just not in excess. For example, although more than 90% of Japanese people are lactose intolerant, most people can drink 200 ml of milk every day without any discomfort.

symptom

Unabsorbed or unbroken lactose can cause symptoms such as intestinal rumbling, abdominal bloating, abdominal pain, flatulence, discomfort, diarrhea, etc. Some people may also experience belching, nausea, etc. These symptoms are called lactose intolerance. Symptoms of lactose intolerance vary greatly from person to person. Severe lactose intolerance usually occurs within 30 minutes to several hours after consuming a certain amount of lactose.

Lactose intolerance has a greater impact on infants and young children, and is accompanied by diaper rash, vomiting, slowed growth and development, etc. Adults sometimes experience nausea. The number and severity of intolerance symptoms are related to many factors, such as lactase activity in the small intestine, the amount of lactose ingested, and whether other types of food are ingested at the same time.

prevention

1. Consume dairy products in small amounts and frequently. Even individuals with lactase deficiency can tolerate small amounts of milk (120ml to 240ml) without experiencing intolerance symptoms. Limit the total amount of lactose consumed in a day. The general lactose limit is 12 grams. Eating small amounts frequently can also reduce lactose intolerance reactions. The amount consumed at one time should not exceed 250 ml. As long as you can grasp the reasonable interval time and total daily milk intake when drinking milk, you can avoid symptoms of lactose intolerance. Please note that infants and young children who are allergic to cow's milk should choose goat's milk or other dairy products.

2. It is not advisable to drink milk on an empty stomach. People with lactose intolerance should not drink milk on an empty stomach in the early morning. Drinking milk while eating other foods, such as dairy products with meat and fatty foods, can reduce or eliminate lactose intolerance symptoms.

3. Use fermented milk (especially yogurt) instead of fresh milk first. 20% to 30% of the lactose in fermented milk has been degraded, making it easy to digest and absorb. Eating yogurt can also improve lactose malabsorption and lactose intolerance, and it is also very convenient to eat.

4. Drink goat milk. The lactose content in goat milk is lower than that in cow milk, and it is rich in ATP (adenosine triphosphate), which can promote the decomposition and conversion of lactose. Therefore, it is not easy to develop "lactose intolerance" after drinking it. For the baby's digestive system, it is recommended to drink goat milk. Goat milk is more stomach-friendly than cow milk, and its rich nutrition is relatively higher than cow milk.