Fast food found to make the immune system more aggressive in the long term

636513502017470287immuneshieldweb.jpg

12 Jan 2018 --- The immune system reacts similarly to a high fat and high-calorie diet as to a bacterial infection, according to a study by the University of Bonn. What is particularly disturbing is that unhealthy food seems to make the body's defenses more aggressive in the long term. Even long after switching to a healthy diet, inflammation towards innate immune stimulation is more pronounced, the researchers found. These long-term changes may be involved in the development of arteriosclerosis and diabetes, diseases linked to Western diet consumption. The results are to be published in the journal Cell.

The scientists placed mice for a month on a so-called “Western diet”: high in fat, high in sugar and low in fiber. The animals consequently developed a strong inflammatory response throughout the body, almost like after infection with dangerous bacteria. 

“The unhealthy diet led to an unexpected increase in the number of certain immune cells in the blood of the mice, especially granulocytes and monocytes. This was an indication for an involvement of immune cell progenitors in the bone marrow,” explains Anette Christ, postdoctoral fellow in the Institute of Innate Immunity of the University of Bonn. 

To better understand these unexpected findings, bone marrow progenitors for major immune cell types were isolated from mice fed a Western diet or healthy control diet and a systematic analysis of their function and activation state was performed.

“Genomic studies did, in fact, show that the Western diet had activated a large number of genes in the progenitor cells. The genes affected included those responsible for proliferation and maturation,” explains Prof. Dr. Joachim Schultze from the Life & Medical Sciences Institute (LIMES) at the University of Bonn and the German Center for Neurodegenerative Diseases (DZNE). 

Fast food thus causes the body to quickly recruit a huge and powerful army. When the researchers offered the rodents their typical cereal diet for another four weeks, the acute inflammation disappeared. What did not disappear was the genetic reprogramming of the immune cells and their precursors: Even after these four weeks, many of the genes that had been switched on during the fast food phase were still active.

“It has only recently been discovered that the innate immune system has a form of memory,” explains Prof. Dr. Eicke Latz, Director of the Institute for Innate Immunity of the University of Bonn and scientist at the DZNE. “After an infection, the body's defenses remain in a kind of alarm state, so that they can respond more quickly to a new attack.” Experts call this “innate immune training.” In the mice, this process was not triggered by a bacterium, but by an unhealthy diet.

The scientists were further able to identify the responsible “fast food sensor” in immune cells. They examined blood cells from 120 subjects. In some of the subjects, the innate immune system showed a particularly strong training effect. In these subjects, the researchers found genetic evidence of the involvement of a so-called inflammasome. Inflammasomes are key intracellular signaling complexes that recognize infectious agents and other harmful substances and subsequently release highly inflammatory messengers. How exactly the NLRP3 inflammasome recognizes the exposure of the body to Western type diets remains to be determined.

Interestingly, in addition to the acute inflammatory response, this also has long-term consequences for the immune system's responses: The activation by Western diet changes the way in which the genetic information is packaged. The genetic material is stored in the DNA and each cell contains several DNA strands, which together are about two meters long. However, they are typically wrapped around certain proteins in the nucleus and thus many genes in the DNA cannot be read as they are simply too inaccessible.

Unhealthy eating causes some of these normally hidden pieces of DNA to unwind, similar to a loop hanging out of a ball of wool. This area of the genetic material can then be read much easier as long as this temporary unwrapping remains active. Scientists call these phenomena epigenetic changes. “The inflammasome triggers such epigenetic changes,” says Dr. Latz. “The immune system consequently reacts even to small stimuli with stronger inflammatory responses.”

These inflammatory responses can in turn accelerate the development of vascular diseases or type 2 diabetes. In arteriosclerosis for example, the typical vascular deposits, the plaques, consist largely of lipids and immune cells. The inflammatory reaction contributes directly to their growth, because newly activated immune cells constantly migrate into the altered vessel walls. When the plaques grow too large, they can burst, leading to blood clotting and are carried away by the bloodstream and can clog vessels. Possible consequences: Stroke or heart attack.

To contact our editorial team please email us at editorial@cnsmedia.com

Related Articles

Nutrition & Health News

Bone and joint health: Consumer demands and promising ingredients

19 Apr 2018 --- Mobility, which incorporates bone and joint health, is becoming a key concern for a range of demographics. NutritionInsight spoke with a number of key suppliers in the bone and joint health space about the key ingredients to look out for, as well as some key consumer demands driving innovation in this space.

Nutrition & Health News

Infant food allergy linked to genetics and skin exposure to food, dust and wipes

19 Apr 2018 --- Food allergy is triggered by perfect storm of genetics and skin exposure to infant wipes, dust and food, according to a new Northwestern Medicine study. Infant and childhood food allergy, whose cause has long been a mystery, has now been linked to a mix of environmental and genetic factors that must coexist to trigger the allergy. The factors contributing to food allergy include the genetics that alter skin absorbency, use of infant cleansing wipes that leave soap on the skin, skin exposure to allergens in dust and skin exposure to food from those providing infant care. Food allergy is triggered when these factors occur together.

Nutrition & Health News

Plant-based possibilities: Report details novel sugar replacements for beverages

19 Apr 2018 --- PreScouter, a Chicago based technology scouting company, details novel replacements for sugars in a new analysis, that are from natural sources, safe, technologically viable and environmentally stable, for use in beverages. The company hopes that the report answers consumer calls for sweeteners that are both natural and healthy, in light of diabetes and obesity epidemics, and that it may aid informing beverage providers on how to best respond to calls for lowering sugar levels in drinks.

Nutrition & Health News

Dosage questions: Green tea supplements may pose health risks, EFSA warns

19 Apr 2018 --- When taken as food supplements, green tea catechin doses at or above 800mg/day may pose health concerns, according to the European Food Safety Authority (EFSA), which assessed the safety of green tea catechins from dietary sources, following concerns regarding their possible harmful effects on the liver. Catechins from green tea infusions and similar drinks are generally safe, the authority found, but certain supplements may be best avoided.

Nutrition & Health News

Collagen beverage innovations: PB Gelatins/PB Leiner to showcase convenient formats

19 Apr 2018 --- PB Gelatins/PB Leiner is marketing innovative solugel collagen products, that they say, make it even easier for their customers to grasp the opportunity collagen can bring to their health. The collagen industry is active and its growth is exemplified by Innova Market Insights figures, which show that there was a +34 percent compound annual growth rate (CAGR) in new product launches for collagen peptides from 2010 to 2016.

More Articles
URL : http://www.nutritioninsight.com:80/news/fast-food-found-to-make-the-immune-system-more-aggressive-in-the-long-term.html