The most serious threat to the human body caused by lactose deficiency is the impact on nutritional status, especially for young children and the elderly. The investigation found that lactose deficiency, the height, and weight of young children are significantly lower than normal children, and the prevalence of rickets and anemia is significantly higher than normal children.
Also, lactase deficiency can not or less take calcium from milk, lower bone density, and increase the prevalence of osteoporosis. Therefore, to understand the cause of lactase deficiency, it is of great significance to pay attention to its correct diagnosis.
Lactose deficiency and classification
Lactose, also known as B-galactosidase, is present on the surface of the small intestinal mucosa. It is encoded by the lactose gene of about 50b on the long arm of chromosome 2 and has two enzyme activities: lactose and phloridzin. The expression of lactose is restricted by the intestinal epithelial cells or absorptive cells to the distal end of the duodenum and the jejunum, and the duodenum proximal and ileum has the lowest activity.
Factors associated with lactose deficiency
Racial factors have been reported to have the highest incidence of lactose deficiency in African American and Asian ethnic groups, close to 10%; blacks and Nordic Jews are 60%-80%; Mexico, Spain and South Africa are 50%-80%, and Caucasians are only 2%-15%. The incidence of LD in Han Chinese adults is 75%-95%, and 76.4%-95.5% in ethnic minorities.
The study found that the adult type lactose deficiency is related to the single nucleotide polymorphisms C/T13910 and C/A22018 located at the 14M and 22b positions upstream of the lactose gene, respectively. Among them, LCr13910c/ is closely related to lactose deficiency. The study also found that genotype C/C13910 was negatively correlated with lactose activity and genotypes CT3910 and Tr13910 with lactose
The activity was positively correlated.
The closer the geographical location in Europe to the south and east, the higher the incidence of lactose deficiency from 2% in Scandinavia to 70% in Sicily. India also has an increase in the incidence from north to south. However, the incidence of lactase deficiency in residents in the same area is higher than that of herders. Whether this difference is related to the eating habits of herders remains to be studied.
Relevant data show that lactose activity continues to decline with age, with 90%-95% of people losing their original lactose activity in early childhood. The activity of lactose in the body is increased from the late gestation period to the mid-neonatal level and begins to decline at the age of 2-15 years. So far, the body begins to express lactose into lactose intolerance. However, 45% of lactose-intolerant women will be able to recover lactose deficiency in children aged 0-6 years in Shanghai, such as the ability to recapture lactose during pregnancy.
The incidence of lactase deficiency was found to be 474% and with age. Increase and rise. A survey of children in four cities in Beijing, Shanghai, Guangzhou, and Hahn showed that the incidence of lactase deficiency in children aged 3-5 years and 7-8 was 38.5% and 82.6%. The specific age at which the activity begins to decline depends to a large extent on the ethnic, cultural background, especially the development of the dairy industry. The decline in lactase activity in China begins with 3-5 years old. But some scholars believe that it started at 7-8 years old.
With the increasing consumption of milk and dairy products, the high incidence of lactose deficiency in the population has gradually increased the problems associated with lactose absorption. The research on lactose deficiency has also received increasing attention, and new diagnostics and treatments are constantly being made. The method came out.
With the deepening of the research on the level of lactose gene, the method of genetic testing is gradually improved, and the method of improving lactose deficiency is also expected to increase. At present, no matter which kind of detection or treatment method has its drawbacks, it is believed that with the joint efforts of many scholars, there will be breakthroughs in the detection and treatment of lactose.