In a new study, researchers found that additives common to processed foods can damage the tight junctions that protect the intestinal mucosa, and which are essential to the intestinal tolerance and immunity balance that works to prevent autoimmune diseases such as multiple sclerosis (MS). The article, titled “Changes in intestinal tight junction permeability associated with industrial food additives explain the rising incidence of autoimmune disease,” was published in the journal Autoimmunity Reviews.

Worldwide, but especially in the West, the incidence of autoimmune disease is increasing, a trend accompanied by the development of the processed food and food additives industries. This steady rise in autoimmunity is also seen in MS, a debilitating disease whose cause is still not fully known, but is suspected to be an interaction of genetic, immunologic and environmental factors.

“In recent decades there has been a decrease in incidence of infectious diseases, but at the same time there has been an increase in the incidence of allergic diseases, cancer and autoimmune diseases,” Professor Aaron Lerner, from the Technion Faculty of Medicine and Carmel Medical Center, Haifa, Israel, and a study lead author, said in a press release. “Since the weight of genetic changes is insignificant in such a short period, the scientific community is searching for the causes at the environmental level.”

Recent research has focused on the role of the intestinal epithelial barrier in maintaining the equilibrium of the immune system response to non-self and self-antigens. The permeability of this barrier is controlled by intracellular tight junctions, a complex network of proteins that regulates trafficking of macromolecules between the environment and the host, and that protects the intestine against colonization by foreign microorganisms. Tight junctions play a crucial role in the equilibrium and balance of the immune response — and tight junction dysfunction leads to a barrier more permeable to bacteria, toxins, allergens, and carcinogens. Tight junction dysfunction is the subject of several research studies, especially in regard to autoimmune disease, where it has been found to be commonly present.

Researchers investigated the correlation between autoimmunity and industrial food additives, used in processed foods to improve such things as taste, smell, texture, and shelf life. They found that the additives glucose (sugars), sodium (salt), fat solvents (emulsifiers), organic acids, gluten, microbial enzyme transglutaminase, and nanometric particles all weakened tight junctions, leading to a more permeable intestinal mucosa, a key factor in autoimmunity. With all the information gathered on this subject, researchers recommend that autoimmune disease patients, and their family members, avoid processed foods as much as possible.

“Control and enforcement agencies such as the FDA stringently supervise the pharmaceutical industry, but the food additive market remains unsupervised enough. We hope this study and similar studies increase awareness about the dangers inherent in industrial food additives, and raise awareness about the need for control over them,” Professor Lerner concluded.