Our immune system protects our body from foreign enemies. It is a mechanism that usually fights viruses and pathogens. However, it can also hurt our body in response to something that should be harmless to the body. Among such reactions, the reaction to food is called “food allergy”. Foods served for school lunches has brought allergic reactions to children, for instance. Food allergies in babies and children have been increasing in recent years and became a serious problem in Japan. Currently, the top three main causes of food allergies in infants and children are chicken eggs milk and wheat. In the past, “soybeans” were often the main cause of allergies, but dietary changes have provided an opportunity to replace soybeans for wheat. An increase of a bread-centered diet is thought to be the cause of the growth of wheat allergies. Experts point out that the increased frequency of use of simple meals such as fast food and sweet buns and the increasing opportunities for children to eat alone contributed to the cause.

Food allergies decrease as the child grows because their digestive functions usually improve. However, it has been noted that the symptoms of feeling dull and unwell after growing into an adult may be related to food allergies. There are immediate and non-immediate food allergies. Both types are closely related to the intestine and immunity. The immediate type appears 1-2 hours after eating causative foods. Since it is relatively easy to determine what you have eaten, you can avoid having allergic reactions without eating the causative foods. On the other hand, the non-immediate type develops symptoms after hours to days. Among these two types, non-immediate food allergies can be involved in bad conditions.

Many bacteria cover the surface of our intestines. The surface is covered with a mucosal barrier. A healthy intestine breaks down food proteins with digestive enzymes. Therefore, a food allergic reaction does not occur, and the digested protein is smoothly absorbed into the body as a nutrient. However, when bacteria are damaged due to stress, malnutrition, or imbalance of intestinal bacteria, food proteins are not properly digested and pass through the intestines as they are. When this happens, immune cells are activated and detect food as a foreign substance. This action further damages the intestines. The intestine is an important organ that absorbs nutrients and also sends signals to the brain. Some non-immediate food 

allergies cause severe symptoms that can threaten our life. Even without serious symptoms, experts suggest that eating only the same food or the reduction of the number of good bacteria in the intestines can lead to continuous mild allergic reactions. Non-immediate food allergies resulting from imbalance of intestinal bacteria may be the cause of bad conditions.

Previously, measures such as “food restrictions during pregnancy and lactation” and “delaying the time to give highly allergic foods as baby food.” were considered to be a prevention against food allergies. However, a new large-scale study has announced worldwide that these attempts are not preventive. Studies have shown that the onset of food allergies is not only due to food intake through the mouth, but also from the skin. It has been suggested that protecting the skin is also important for preventing food allergies, based on the research reporting that moisturizing skin from early infancy can prevent the onset of atopic dermatitis.

The relationship between skin and food allergies in adulthood is also drawing attention. A few years ago, a major case occurred in Japan where the wheat protein presented in the soap containing hydrolyzed wheat entered through the skin and subsequent exercise caused anaphylactic shock. This case has demonstrated that optimal skin care is indispensable as a countermeasure against allergies.

As with optimal skin care, balancing the intestines, which are at the forefront of immunity, is important. The intestinal bacteria produce digestive enzymes and break down food proteins. In addition, the compounds produced by bifidobacteria have the effect of repairing intestinal cells. Increasing the good bacteria is essential to achieve the intestinal environment that can be protective against allergies.

Due to the complexity of the path of food allergy, there is no reliable cure yet. It is dangerous to take extreme measures at your own discretion. If you continue to have eczema or diarrhea, you should consult a specialist as soon as possible.