Western diet makes the immune system hyperactive: vascular diseases are promoted
The immune system reacts to a high-fat and high-calorie diet in a similar way to a bacterial infection. Your body's defenses remain hyperactive long after you switch to a healthy diet. This is shown by a current study led by the University of Bonn. The scientists put mice on a so-called Western diet for a month: a lot of fat, a lot of sugar, little fiber. The animals then developed massive inflammation - almost like after infection by dangerous bacteria.
“The unhealthy diet has led to an unexpected rise in some immune cells in the blood. This was an indication of the involvement of progenitor cells in the bone marrow in the inflammatory process, »said Anette Christ from the Institute for Innate Immunity at the University of Bonn. Blood-circulating immune cells develop from these precursor cells.
One speaks here of a genetic reprogramming of the innate immune system: »Genomic studies show that a large number of genes are activated in the progenitor cells by the Western diet. The unhealthy diet means that the body quickly and excessively recruits a huge, powerful combat force, «explains Professor Joachim Schultze from the Life & Medical Sciences Institute (LIMES) at the University of Bonn.
This "fighting force" - actually important for the defense against bacteria and viruses - can drastically accelerate the development of vascular diseases: In arteriosclerosis, the typical vascular deposits, the plaques, consist largely of fats and immune cells. The inflammatory response contributes directly to their growth; because new activated immune cells constantly migrate into the changed vessel walls. If the plaques become too large, they burst open, are carried away by the blood stream and can clog other vessels. Possible consequences are stroke and heart attack.
Particularly fatal: If the scientists now offered the rodents typical cereal food for a further four weeks, the acute inflammation disappeared, but not the genetic reprogramming of the immune cells: even after these four weeks, many of the genes that were active in the »Fastfood -Phase «had been switched on. Professor Eicke Latz, head of the Institute for Innate Immunity at the University of Bonn and scientist at the German Center for Neurodegenerative Diseases (DZNE): “We have only recently learned that the innate immune system has a memory. After an infection, the body's defenses remain in a kind of alarm state so that they can then react more quickly to a new attack. «In the mice, this process was not triggered by microorganisms, but by an unhealthy diet.
The scientists then developed a cell culture system with isolated immune cells from human blood. They were even able to identify the "fast food sensor" in the immune cells. They were able to demonstrate that a change in the genetic code - caused by certain food ingredients - has an impact on memory development and the associated excessive immune response.
Malnutrition can have dramatic consequences. Over the past few centuries, average life expectancy in Western countries has risen steadily. This trend is being broken for the first time: Those who are born today will probably live on average shorter than their parents. Wrong food and too little exercise should play a decisive role in this. Rüdiger Lobitz, resp