Infection as a Trigger for Autoimmune Disease
Many people are familiar with the idea autoimmune disease runs in the family; this is because there are clear genetic links connecting autoimmune disease to family members. After all, your genetics come from your parents.
One thing that surprises a lot of my patients, is that genes only pay a small role in autoimmune disease!
Think of it this way: genetic factors pre-dispose for autoimmune disease, but environmental factors clearly serve as triggers for disease [1]. In fact, 30% of autoimmune disease arise from genetic factors and 70% comes from environmental factors [5].
This article will introduce you to the concept of Environmental factors affecting autoimmune disease. If you’re interested in learning more about the genetic aspects, please click here.
What Are Environmental Factors?
Environmental factors are the things in our environment, but not only the obvious things like air pollution and chemicals. We count food, infections and toxins all to be part of our environment, and all of these contribute to autoimmune disease onset and progression.
Proof Environment Factors Matter
There is good scientific evidence proving how impactful the environment plays in autoimmune disease.
Monozygotic twins (same genes) living in different environments can have different rates of autoimmune disease [2].
Both human and animal models show a cascade of events may occur [5]:
- Environmental trigger sets off our immune system
- Breakdown in or immune tolerance mechanisms
- Change in the gut microbiota
- Enhanced gut permeability to large molecules
- Immune reactivity
- Autoimmune processes may begin
Toxins
There are many, many toxins identified as triggers in autoimmune disease. Some common ones are discussed here, look out for future posts on this topic.
Environmental Toxins
Bisphenol A (BPA)
- 90% of Americans had trace amounts of BPA in urine [5]
- Linked to autoimmune disease; its an endocrine disruptor
- 11 different pathophysiological and immunological pathways have been presented where BPA may lead to autoimmunity [5]
- BPA is often consumed in plastics
Mercury
- It’s thought mercury through high fish consumption has a link to autoimmune disease
- studies in Native American Sioux Tribes. Gender, Mercury and Arsenic were part of a complex interaction that underlies autoimmunity [5]
Asbestos exposure
- Specifically linked to Rheumatoid arthritis, systemic sclerosis and systemic lupus erythematosus.
Trichlorethylene (TCE)
- TCE is an industrial solvent
- Known for being neurotoxic, hepatotoxic, nephrotoxic, immunostimulant, carcinogenic [5]
- Mouse studies showed exposure to TCE to genetically susceptible mice triggered autoimmunity [5]
Medications
A wide range of medications are implicated in setting off autoimmune disease in genetically susceptible individuals.
There are various medications linked to specific conditions. Lupus is a specific one, where we have several drugs that can cause joint pain, muscle aches and fatigue [7] – a presentation similar to Systemic Lupus Erythematous. More info can be found in an accompanying blog post.
Infectious Etiology
There’s still a lot of mystery around this concept, but it is true that certain infections can lead to autoimmune disease in genetically susceptible individuals. In a nutshell, certain autoimmune diseases are linked to certain genetic findings and certain genes are known to be turned on by infectious agents (bacteria or viruses). This explains why some people suddenly present with autoimmune disease after a common illness such as a common cold, food poisoning or other otherwise insignificant acute illnesses.
We are now more familiar with how we can go from basic infection to autoimmune disease. The diagram here highlights a rough timeline of how things can progress.
This is another topic in which future articles will highlight this surprising connection.
Dietary Factors
The foods we eat every day also contribute to gut health and consequently immune function. We have evidence showing the typical western diet increases risk for autoimmune disease (in genetically susceptible people). A diet high in fat (bad fats) with high carbs, high protein, high salt and frequent consumption of processed foods are linked to autoimmunity [1].
It’s true over consumption of food (leading to obesity) has it’s own links to autoimmunity [3], but its also what’s in your food that matter. Look out for more blog posts on this important factor.
Genetic Susceptibilities
Don’t forget, all the above factors are triggers for autoimmune disease. These are triggers for certain genes, which may affect the onset of certain diseases. The analogy I use with patients is that we’re born with genes. Those genes have little switches on them, and during our lives, certain factors may turn these switches/genes on or off. More info on this topic can be found here.
Review
We know the environment plays a crucial role in the onset and progression of autoimmune disease. I’m alarmed by how few of my patients know of these factors – because these are the factors we all have control over. As more and more research sheds light on these factors, trust that these articles will be updated accordingly.
