Researchers have found that the immune system has been shown to react to fast foods containing excess salt and calories and this activation of the immune system to fast foods is similar to its reaction to bacterial infections. The study findings reported in the latest issue of the journal Cell.

The researchers noted that the body responds aggressively to bacterial infections and acts in a similar manner with fast food consumption. The defences become more aggressive with time when a person takes fast foods. The problem remains even after the body has switched over to healthier diets, the researchers find.

The stimulation of the immune system and inflammatory reactions have been linked to several diseases such as arteriosclerosis and diabetes. For this study, the team of researchers placed some lab mice on a western diet or a diet of fast food with excess fat, sugar and salt and low amounts of fibre.

The team noted that the mice showed increased inflammatory reactions within their bodies. The inflammation was similar to a response to a bacterial infection. The unhealthy diet was responsible for producing certain immune cells (granulocytes and monocytes) in the mice’ blood, the researchers said.

The bone marrows of the mice that produced the immune cells seemed to have been stimulated by the diet. The team analyzed the changes in the bone marrow of the mice of the healthy diet and those on the western diet. The functions of the bone marrow, as well as their activation states, were noted.

The bone marrows were subjected to genomic tests to look at the genes that had been activated by the inflammatory status. The results indeed revealed that the genes of the bone marrow had been altered to produce more immune cells. The fast food stimulates the early and rapid maturation of the immune cells.

Hence, an army of white blood cells is created within a short period of time within the body in response to fast foods. The researchers then withdrew the unhealthy diet in the mice and gave them a normal healthy cereal diet. The blood levels of the immune cells reduced and became normalized.

The genetic reprogramming of the bone marrow that the initial inflammation had already caused was not changed. Four weeks of healthy diet failed to change the alertness of the immune system or the overdrive on inflammation they concluded. The researchers called this an immune system memory.

Further, the scientists checked on humans from the blood cells of 120 participants. They noted that some of these persons were genetically programmed to have the immune system memory that could be triggered by the unhealthy diet. The actual molecular mechanisms are being explored.

Experts tem this “innate immune training” where the body is alert for new infections or attacks. In this case the process was not stimulated by a bacterial infection but an unhealthy diet. The study cleared that this state of inflammation overdrive can lead to health problems such as diabetes and atherosclerosis leading to heart attacks and strokes.