Processed foods are defined by the US Food and Drug Administration (FDA) as "any food other than a raw agricultural commodity and includes any raw agricultural commodity that has been subject to processing, such as canning, cooking, freezing, dehydration or milling."
This means that cheese, breakfast cereals, canned fruits and vegetables, bread, savory snacks and meats such as bacon and sausages are also examples of foods that have been subject to some form of processing.
A number of studies have reported the negative health effects of consuming some processed foods, including increased risk of weight gain and heart disease. And last October, the World Health Organization (WHO) concluded that eating processed meats can cause colorectal cancer.
Now, Prof. Aaron Lerner, of the Technion-Israel Institute of Technology in Haifa, Israel, and Dr. Torsten Matthias, of the Aesku-Kipp Institute in Germany, suggest the consumption of processed foods may be associated with development of autoimmune diseases.
An autoimmune disease occurs when the immune system attacks healthy cells in the body, mistaking them for foreign invaders. This can lead to destruction of body tissue and abnormal organ growth and function.
There are more than 100 types of autoimmune disorders. Some of the more common forms include celiac disease, type 1 diabetes, multiple sclerosis (MS), Crohn's disease and rheumatoid arthritis.
Prof. Lerner and Dr. Matthias note that there has been a rise in both the prevalence of autoimmune diseases and consumption of processed foods in recent years. For their study, they set out to determine whether there is a link between the two.
Specifically, the researchers looked at how certain additives in processed foods - used to improve the taste, texture, smell and shelf life - affect the intestines and the development of autoimmune diseases.
The team explains that many autoimmune diseases are triggered by dysfunction of "tight junctions" in the intestine, which are sealants between epithelial cells that protect the mucosa - the lining of the gastrointestinal tract that helps food pass through.
Normal-functioning tight junctions help protect the immune system from bacteria and other foreign bodies, but any damage to the tight junctions can lead to what is called "leaky gut" - in which toxins can enter the bloodstream, potentially leading to the development of autoimmune diseases.
In their study, the researchers identified at least seven common food additives - including glucose, gluten, sodium, fat solvents, organic acids, nanometric particles and microbial transglutaminase (an enzyme used as a food protein "glue") - that weakened tight junctions in the intestine.
Based on their findings, the researchers suggest that consumption of processed foods may increase the risk for autoimmune diseases. They note that the food additive market is not highly regulated, making such findings a cause for concern.
Source: Medical News Today