Fast food makes the immune system more aggressive in the long term.

Study shows that even after a change to a healthy diet, the body's defenses remain hyperactive.

The immune system reacts similarly to a high fat and high calorie diet as to a bacterial infection. This is shown by a recent study led by the University of Bonn. Particularly disturbing: 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.

These long-term changes may be involved in the development of arteriosclerosis and diabetes, diseases linked to Western diet consumption.
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," Anette Christ, postdoctoral fellow in the Institute of Innate Immunity of the University of Bonn explains.
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.

"Fast food sensor" in the immune cells
"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," explains Dr. Latz. "The immune system consequently reacts even to small stimuli with stronger inflammatory responses."

Dramatic consequences for health

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.

Wrong nutrition can thus have dramatic consequences. In recent centuries, average life expectancy has steadily increased in Western countries. This trend is currently being broken for the first time: Individuals born today will live on average shorter lives than their parents. Unhealthy diets and too little exercise likely play a decisive role in this.

"These findings therefore have important societal relevance," explains Latz. "The foundations of a healthy diet need to become a much more prominent part of education than they are at present. Only in this way can we immunize children at an early stage against the temptations of the food industry. Children have a choice of what they eat every day. We should enable them to make conscious decisions regarding their dietary habits."

The research involved groups from the Netherlands, the USA, Norway and Germany. Latz and Schultze are members of the excellence cluster "ImmunoSensation," which investigates the innate immune system. Latz is considered a leader in the field of innate immunity and he has been awarded the Gottfried Wilhelm Leibniz Prize for his work in December 2017. This is considered one of the most prestigious science awards in Germany.

Anette Christ, Patrick Günther, Mario A.R. Lauterbach, Peter Duewell, Debjani Biswas, Karin Pelka, Claus J. Scholz, Marije Oosting, Kristian Haendler, Kevin Baßler, Kathrin Klee, Jonas Schulte-Schrepping, Thomas Ulas, Simone J.C.F.M. Moorlag, Vinod Kumar, Min Hi Park, Leo A.B. Joosten, Laszlo A. Groh, Niels P. Riksen, Terje Espevik, Andreas Schlitzer, Yang Li, Michael L. Fitzgerald, Mihai G. Netea, Joachim L. Schultze, Eicke Latz. Western Diet Triggers NLRP3-Dependent Innate Immune Reprogramming.Cell, 2018; 172 (1-2): 162 DOI:10.1016/j.cell.2017.12.013
 
University of Bonn. (2018, January 11). Fast food makes the immune system more aggressive in the long term: Study shows that even after a change to a healthy diet, the body's defenses remain hyperactive. ScienceDaily. Retrieved September 11, 2021 from www.sciencedaily.com/releases/2018/01/180111141637.htm

15 Super Fruits For Ultimate Immunity

1. Strawberries: Strawberries are quite important for boosting immunity and energizing cellular health. Strawberries are loaded with vitamin C. One cup of strawberries contains about 136% of the RDA of vitamin C. The phyto-nutrients in this fruit strengthen the immune system and combat colds, flu, infections and viruses. The presence of vitamin C not only enhances immunity but aids blood pressure regulation, age-related ocular disease, and muscle wasting. One major drawback is that strawberries are also the number one most contaminated fruit from pesticides. The point here is to buy organic only!

2. Kiwi: Kiwi contains high levels of Vitamin C contributing to improved immunity and protection from infection. Kiwi helps lower bad cholesterol and maintain blood pressure levels. It has potassium which aids the immune system offering relief from viruses.

3. Watermelon: Watermelon is full of antioxidants and phyto-chemicals. This fruit is packed with the best of the best antioxidants. Glutathione, vitamin C, Vitamin A, and Beta-carotene are extremely beneficial in controlling free radicals helpful in fighting diseases.

4. Pomegranate: This fruit has the ability to fight against infections. It has an adequate amount of vitamin C including other antioxidants, which help the body to fight against bacteria, viruses, and flu. Accordingly, regular consumption of pomegranate or its juice, helps to strengthen immunity.

5. Almond: The almond is full of energy and Vitamin E. Vitamin E, an important anti-oxidant for immunity. Almonds also contain iron and protein which contribute to a high functioning immune system.

6. Papaya: Papaya has the enzymes papain and chymopapain which are very effective in fighting inflammation. Papaya also has numerous micro-nutrients that are excellent for overall health and immunity.

7. Blueberries: Blueberries play a role in combating infection. Vitamin C, vitamin E, help strengthen the immune system.

8. Winter Cherry: Known for treating tuberculosis and used to strengthen the immune system and combat infection.

9. Cantaloup/Muskmelon: High in vitamin C. It stimulates the immune system to fight against viruses, bacteria, and infections.

10. Rambutan: This fruit has antibacterial and antiseptic properties, which help to fight various forms of infections. 

11. Apple:   Good levels of vitamin C plus iron effective in boosting red blood cells for immunity.

12. Orange: Orange helps to minimize the impact of type II diabetes and atherosclerosis. The flavonoids like hesperidin and naringenin are anti-inflammatory helping to improve immunity.

13. Pineapple: Pineapple has anti-viral, anti-bacterial, and anti-fungal properties. It is loaded with many minerals and nutrients including a high level of vitamin C. Pineapple is a powerful immune boosting fruit.

14. Pear:  Anti-oxidants in the form of vitamin C and copper help develop immunity. 

15. Sapodilla: Sapodilla has tannins, powerful antioxidants that act as anti-viral, anti-bacterial, anti-inflammatory, and anti-parasitic fighters. Sapodilla is loaded with vitamin E, vitamin A, vitamin C, and vitamin B complex. These vitamins and antioxidants boost the immunity of the body.

Eating green veggies improves immune defenses

Date: October 17, 2011Source:Cell PressSummary:

Researchers have found another good reason to eat your green vegetables, although it may or may not win any arguments with kids at the dinner table. Researchers reporting online in the journal Cell, a Cell Press publication, on October 13th have found another good reason to eat your green vegetables, although it may or may not win any arguments with kids at the dinner table.
 
It turns out that green vegetables -- from bok choy to broccoli -- are the source of a chemical signal that is important to a fully functioning immune system. They do this by ensuring that immune cells in the gut and the skin known as intra-epithelial lymphocytes (IELs) function properly.
 
"It is still surprising to me," said Marc Veldhoen of The Babraham Institute in Cambridge. "I would have expected cells at the surface would play some role in the interaction with the outside world, but such a clear cut interaction with the diet was unexpected. After feeding otherwise healthy mice a vegetable-poor diet for two to three weeks, I was amazed to see 70 to 80 percent of these protective cells disappeared."

Those protective IELs exist as a network beneath the barrier of epithelial cells covering inner and outer body surfaces, where they are important as a first line of defense and in wound repair. Veldhoen's team now finds that the numbers of IELs depend on levels of a cell-surface protein called the aryl hydrocarbon receptor (AhR), which can be regulated by dietary ingredients found primarily in cruciferous vegetables. Mice lacking this receptor lose control over the microbes living on the intestinal surface, both in terms of their numbers and composition.

Earlier studies suggested that breakdown of cruciferous vegetables can yield a compound that can be converted into a molecule that triggers AhRs. The new work finds that mice fed a synthetic diet lacking this key compound experience a significant reduction in AhR activity and lose IELs. With reduced numbers of these key immune cells, animals showed lower levels of antimicrobial proteins, heightened immune activation and greater susceptibility to injury. When the researchers intentionally damaged the intestinal surface in animals that didn't have normal AhR activity, the mice were not as "quick to repair" that damage.
 
As an immunologist, Veldhoen says he hopes the findings will generate interest in the medical community, noting that some of the characteristics observed in the mice are consistent with those seen in patients with inflammatory bowel disease.
 
"It's tempting to extrapolate to humans," he said. "But there are many other factors that might play a role."

For the rest of us, he says, "it's already a good idea to eat your greens." Still, the results offer a molecular basis for the importance of cruciferous vegetable-derived phyto-nutrients as part of a healthy diet.   

HOW MANY SERVINGS OF FRUIT & VEGGIES RECOMMENDED A DAY?

  Top ten fruits for boosting immunity

  

DID YOU KNOW THAT EATING MORE PLANTS CAN …

help prevent (and in some cases reverse!) some diseases, cancers & health issues? Like heart disease, diabetes, breast cancer, Parkinson’s. So amazing, right? I highly recommend How Not to Die by Dr. Michael Gregor, who also is the founder of nutritionfacts.org, if you’d like to learn more.

help improve your gut health? Many fruits and veggies are high in fiber, which can help you become more regular, and help with your digestion. A healthy gut is a happy gut.   

help boost your mood? There have been studies that show that eating more plants and less meat and animal products may be linked to less depression. 

lead to living longer happier lives (in some cases)? Researching the Blue Zones for longevity and happiness (places throughout the world where people live the longest and are believed to be the happiest), people there have at least one thing in common: they eat lots of fruits and veggies. 

HOW MANY SERVINGS OF FRUIT AND VEGETABLES ARE RECOMMENDED A DAY?
Have you ever googled how many servings of fruits and veggies you need in a day? The answers are all over the place. From 4-5; 5-13; 10 … And it’s confusing the different suggestions for servings or cups (are they the same thing?!) Nobody seems to agree!

The USDA currently recommends between 3 1/2 and 5 cups of fruits and veggies a day for women between the ages of 31 and 59 [5]. Beans, peas and lentils are included in that amount too. So, really that’s not a lot. Also, to note that 2 cups of raw spinach or greens equals 1 cup, according to the USDA.

Some nutrition experts suggest eating more. The American Heart Association recommends eating 4 servings of fruit and 5 servings of veggies a day [6]. In How Not to Die, author Michael Greger, M.D., suggests eating 10 servings of fruits and veggies a day [7]. The Academy of Nutrition & Dietetics recommends 2 cups of fruit plus 2 1/2 cups of veggies a day [8]. In Deeply Holistic, author Pip Waller suggests eating at least 8 servings a day. Other organizations suggest filling half your plate with fruits and veggies [9].