Diet can have a direct, specific and significant effect on your immune systems ability to prevent and also fight various infectious diseases... bacterial and viral.
This connection is also not hypothetical. It can be explained in quite simple terms using concepts taught in first year medical school Immunological terms. This article will outline the connection between your diet and immune system and how you can manipulate your diet to support your ability to fight off and prevent infectious illnesses.
First... some basic background information on how your immune system keeps these foreign invaders (pathogens) at bay. This background information is critical in order for you to understand the connection between your diet and your immune systems ability to fight infections, so please bare with the short biology lesson.
The immune system is incredibly complex with many different major components all intricately connected and working together to keep unwanted invaders out of your body and from affecting your health. Your immune system acts like your "armed forces" keeping enemies away. One of the major components of your "armed forces" are your white blood cells. Think of them as the "Generals" of your immune system.
There are many different kinds of white blood cells all with specific purposes, but essentially they all roam through your body (blood, lymphatic system, etc.) and look for foreign invaders or pathogens ( Pathology Generators ) to attack and eliminate.
One specific type of white blood cell is called a T-Cell. These cells roam through your body in search of pathogens to attack. When it comes in contact with an pathogen it binds to it and calls another type of white blood cell called a B-Cell and binds to it as well. Now you have T-Cell bound to B-Cell bound to a Pathogen. This T-Cell / B-Cell / Pathogen complex now turns into a "photocopy shop". It begins "printing off" compounds called antibodies or immunoglobulins. Think of these antibodies as little cloned soldiers which are produced specifically to go out into the system and seek out and attack anything that looks like the pathogen. It is these antibodies which are critical for mobilizing an "attack" against the pathogen and ultimately killing it, before the pathogen has a chance to kill you.
This is exactly how vaccines work. A vaccine is made of proteins from dead or functionally inert infectious agents (ie. Influenza Virus for the Flu vaccine, Tetanus for tetanus vaccines, etc.) The vaccine gets injected into the body. The white blood cells recognize the vaccine as being "foreign" to the body, bind to it and begin producing antibodies / immunoglobulins to go back in the body and seek out and destroy anything that looks like the vaccine.
A couple key points to this vaccine methodology. First, it only takes a tiny dose of vaccine (1/2 ml) to produce an exponentially large (trillion fold) antibody response to it through the "photocopy shop". Second, the antibody level in the blood stream can take several weeks to reach it's peak (this is why you need to have a vaccine 2-4 weeks before traveling). And finally the antibodies to the vaccines can stay in the system for months to several years. A tetanus vaccine is good in your system for 8-10 years. These aspects to vaccines are critical to remember when discussing food allergies and how it impacts your ability to fight infections.
So how does this correlate in any way to our diets?
Well our immune system (white blood cells, T Cells, etc) can just as easily recognize certain foods as being "foreign" to the body and can begin producing the same antibodies / immunoglobulins to these foods in exactly the same way as it does to vaccines and infectious agents. This is a type of food allergy (immune system response to a food in your diet). Think of a peanut to a person with anaphylactic reactions to peanuts. Or think of Gluten to a person with Celiac disease.
There are different types of food allergies and most people only know of one type, the anaphylactic type. A child eats a peanut and their throat swells. Another person eats shell fish and they vomit. Another person may eat a different food and get hives immediately after.
These types of allergies are called Immediate Hypersensitivity Reactions because the reactions happen immediately following the ingestion of the food. These allergies are the type that are tested for with scratch testing with an allergist. These ARE NOT the types of food allergies that I'm suggesting have the Antibody / Immunoglobulin response mentioned above.
The antibodies associated with this type of allergy are called Immunoglobulin E ( IgE antibodies). These antibodies will cause immediate inflammatory reactions (swollen throat, hives, vomiting, etc) so they are obvious and easy to figure out. (please read the following article for a detailed explanation on the difference types of allergies... Food Allergies and Intolerance's... whats the difference? )
The type of allergy relating to the vaccine example given above is called a Delayed Hypersensitivity Reaction. With this type of allergy to a food, the antibodies (Immunoglobulin G or A, IgG or IgA) can take hours to weeks to get produced and back into the system (similar to a vaccine) where they then can cause inflammatory reactions.
Since there is no immediate response to the food (as there would be with the immediate type of food allergy) we don't correlate the food with the reaction that occurred hours to days later. Also the antibodies to this food can take weeks to months to get out of the system ( similar to a vaccine). And finally it only takes a 1/2 ml dose of tetanus vaccine to provide Immunoglobulin based immunity for up to 10 years. It only takes a tiny dose of the allergic food to elicit an Immunoglobulin response that can last for weeks to months.
You can eat a food today, have a reaction / symptom to that food several days after you eat it and you never correlate the food to the symptom. The reaction / symptom can last several days to weeks. And since you don't correlate the first ingestion with the onset of the symptom, you continue to eat the reactive / allergic food on a regular basis. This is what can lead to long term chronic inflammatory issues and immune suppression without ever knowing whats causing it.
The antibody response (and hence the inflammatory response) overlaps and compounds each time the food is eaten. This leads to chronic inflammatory issues and immune suppression.
Many in the conventional health field consider these types of food allergies as not important (they call them sensitivities) and in fact some consider them to be "not real" and unscientific and medically unvalidated. But there are conventional medical examples for these types of reactions that have been proven and accepted for decades. Celiac Disease and Gliadin. This isn't disputed medically. It's known that these patients produce IgA antibodies to Gliadin and these antibodies then travel to mucous lining of the bowel and cause inflammatory bowel disease (Celiac Disease). The discrepancies come from the fact that they don't recognize people can produce different types antibodies (IgG or IgA) to different foods and that the antibodies can go to different parts of the body and cause inflammation there.
If one person can produce an IgA antibody to Gliadin and the antibody cross reacts with a tissue protein in the bowel and causes Celiac Disease... why couldn't a different person with different genes and DNA produce a different antibody (IgG or IgA) to a different food and it go to a different part of the body and cause inflammation in a different tissue? This is logical. We know there is genetic variation with allergies. Some people have celiac disease and some don't. Some have peanut allergies and some don't. Some have shellfish allergies and some don't. Its not logical think that these other possibilities don't exist!
There is conventional medical researching supporting this idea with many other foods.
The following studies correlated Dairy protein with Type I diabetes in kids (which is an autoimmune, inflammatory condition affecting the pancreas).
In the references above, please note the antibody used as the marker in the study was an IgG (Immunoglobulin G) antibody to proteins found in Cow's milk (Bovine serum albumin and Casein) The antibodies produced against vaccines are Immunoglobulin G ( IgG ) antibodies. The same antibodies! These examples show the delayed hypersensitivity reactions are very real reactions backed by examples and research in the conventional medical world. This in not a theoretical concept.
With all this back ground, the correlation between our immune systems ability to fight off infectious agents and dietary food allergens becomes quite clear.
The immune components and the antibodies produced by them against bacteria, viruses, infections etc. are the exact same immune system components and antibodies that can produced against foods. (IgG and IgA). These are also responsible for identifying and eliminating other atypical and unwanted "invaders" or products in the body such as cancer cells.
When allergic dietary proteins (Food Allergens) are presented to the T Cells in the blood stream, the immune response will be the same as for infectious agents. IgG and IgA antibodies can be produced in the same manner as the vaccine reactions discussed earlier.
There is a critical difference in this scenario from a food allergen perspective as compared to a vaccine or infectious condition perspective.
When you get a vaccine, you typically get it once (some may require a booster) so your immune response ( T Cell B Cell Antibody Production response ) only has to happen and "react" that once to the vaccine. The immune system does it's job, the antibodies are produced and then the immune system can prepare to fight and react against the next "invader".
When your immune reacts against a flu virus or infection, it will react to it until the infection is cleared and then it settles down and prepares to fight and react against the next "invader".
In both of these examples there is an individual agent for the immune system to react against, and once the agent is cleared the immune system can ready itself for the next issue. It has time to recover and replenish itself.
Imagine you have some of the hidden delayed onset food allergies and imagine its something you eat on a regular or daily basis. Each time you eat that food, regardless of the dose (remember the dose of the tetanus vaccine for ten years of immunity... 1/2 ml), you can produce a T Cell B Cell Antibody production response to that food. The immune system is fighting a new "invader" each time the food is eaten. The immune system never gets a chance to rest and recover.
This can put a tremendous and persistent strain / drain on your immune system resources and can have a significant Immune Suppression effect. In simple terms, if your immune system is busy fighting one chronic and persistent immune agent (food) there will be less immune resources to go and fight other things the immune system is meant to fight (infectious agents).
This is only one significant impact of these food allergens on your bodies ability to fight infectious agents. There is another aspect that it just as important and impactful.
In many cases, the antibodies (IgG and IgA) can go back into the body and actually cause inflammatory issues in various parts of the body (as per the Celiac and Diabetes examples mentioned earlier).
One good example involves IgA antibodies which are antibodies that are secreted into the mucous membranes of the body. The mucous membranes are tissues in the body with a slimy mucous film on it. Your digestive tract from the mouth to the rectum and your respiratory system from the back of the throat down into the lung. These antibodies get secreted into the mucous membrane of the digestive tract starting at the tonsils. The tonsils are considered lymphoid tissue, which is where antibodies go to mature before being secreted in the tissues they are designed to protect. (Celiac is an IgA antibody affecting the mucous membrane of the colon).
Imagine you eat a food and produce IgA antibodies to "attack" that food. These antibodies then get secreted on the surface of the tonsil. The next time you eat that food, you have an antibody on the surface of the tonsil designed to attack that specific food. When the food hits the surface of the tonsil, you can get an inflammatory response on the surface of the tonsil. This is a common food cause for tonsillitis.
This same process could take place in the back of the throat. This chronic inflammatory reaction in the mucous membrane in the back of the throat will lead to a weakening of the mucous membrane in that area. This can lead to a susceptible area for colds and infections to take root. This is what many colds and flus start as a tickle in the back of the throat, leading to a sore throat.
If this same inflammatory response occurs in the mucous membrane of the sinus, we can have chronic sinus congestion and increased susceptibility and recurrence of sinus infections.
If this same inflammatory response occurs in the mucous membranes of the lungs and respiratory track, we can have chronic respiratory tract irritation and increased susceptibility to lung and bronchial infections and diseases.
This response can also go down the digestive tract beyond the back of the throat. It can lead to recurrent gastritis and reflux issues in the stomach. It can lead to small intestine irritation and food intolerances associated with low digestive enzyme levels. It can lead to other colon issues such as constipation and other inflammatory bowel diseases.
The key point here is the food allergy often leads to inflammatory issues in the body, and these inflammatory issues can lead to increased susceptibility other illnesses.
It is medically accepted and understood that the Immune Compromised and those with Pre-existing Conditions are more likely to have more severe manifestations of various infectious illnesses when they are contracted.
The following image shows an ELISA (Enzyme Linked Immuno-Sorbant Assay) test done to identify food antibodies / immunoglobulins (IgG and IgA) in the blood stream of a patient. It's important to note that many in the conventional and complementary health field feel this testing to be "invalid". ELISA testing is a gold standard test used in the conventional medical world to identify types of protein in the blood stream, including immunoglobulins for vaccine titres and also for gliadin / transglutaminase testing for Celiac disease. So when someone in the conventional medical system says this type of testing is invalid, they are essentially many of their own tests are done by an invalid method. This isn't the case. The conventional medical system doesn't test for other food antibodies aside from Celiac testing and therefore assume that testing for these other foods must be invalid.
If you look at the extensive list of food immunoglobulins found in the blood stream of this patient, it's very easy to see the extra work that persons immune system is doing just in response to diet allergens. Every time one of those reactive foods is eaten, the immune system will initiate another immunoglobulin production phase against that food.
Another key point here is that many of these foods are foods that many people consider healthy for us for various reasons. Yogurt for healthy gut flora. Whey protein for smoothies as a protein supplement. Dairy in general because of it being a calcium source. Eggs as a hearty and simple protein for breakfast. Bananas for potassium. Cranberry for anti-oxidants and for urinary tract health. Pineapple for inflammation and digestive support. All of these foods are eliciting an immune and potentially inflammatory response in that patients body.
We tend to live our dietary lives based off generic and general dietary ideals as to what a good diet is for us. But the fact is sometimes these generic ideals don't line up with our immune system and this can cause big health issues for many patients. The ideal anti-inflammatory diet is unique to each of us. (Article link) An anti-inflammatory, immune boosting food for one of us, may be an inflammatory and immune draining food for another.
By identifying and removing these delayed hypersensitivity reactions to foods in our diet, we can boost our immune system by getting rid of what's draining it. We can also reduce our susceptibility to catching infections by improving our body's mucous membrane barriers to infections.
Also by removing these immune system strains and drains, we can significantly improve the effectiveness of other complementary approaches to support and boost the immune system (herbal medicines, vitamin and mineral therapies, nutraceuticals, etc. )
Plug the holes in the bottom of the immune system bucket and the therapies pouring in the top of the bucket will work much better.
For more information on these types of food reactions please go to the following link "Food Allergies and Intolerance's" and read the articles (links) presented on that page.