What’s the link between autoimmune diseases and genetics? What other factors contribute to autoimmune disease development?
Amy Myers, functional medicine physician and the author of The Autoimmune Solution, explores the causes of autoimmune diseases. While many physicians attribute autoimmune conditions to genes, Myers says there’s a lot more at play.
Here’s why genetics is only a small piece of the autoimmune puzzle.
The Multi-Dimensional Cause: Much More Than Genetics
While traditional doctors often say autoimmune disease and genetics are strongly linked, Myers explains that autoimmunity has multiple causes beyond just genetics.
Myers believes that the genes predisposing you to develop an autoimmune condition activate when your immune system becomes chronically stressed and dysregulated. This means that while genetics play a role in causing autoimmunity, they’re not the sole cause.
(Shortform note: The idea that environmental and lifestyle factors, rather than solely genetics, contribute to autoimmune conditions aligns with the principles of epigenetics. Epigenetics refers to how environmental and lifestyle factors interact with your genes. For example, you might have the gene for celiac disease—the autoimmune disease that makes people intolerant to gluten—but if you don’t eat much gluten, the gene might not activate. It’s possible that you won’t then develop celiac disease. Researchers believe that chronic stress and lifestyle choices can trigger epigenetic modifications that activate genes predisposing people to autoimmune diseases.)
Below, we’ll explore five immune system stressors that can lead to autoimmunity.
Stressor 1: An Unhealthy Digestive System
Myers argues that digestive health is crucial for immune function. She emphasizes that about 80% of your immune system overlaps with your digestive system. For example, the saliva in your mouth and the good bacteria in your stomach neutralize many of the germs that enter your body through food or water. However, many factors can disrupt gut health, including the following:
- Inflammatory foods (especially gluten, dairy, sugar, and processed foods)
- Medications (particularly antibiotics)
- Chronic stress
- Infections
According to Myers, an unhealthy digestive system can trigger autoimmunity by creating a leaky gut. Certain foods thin the lining of your intestines, allowing partially digested food particles, toxins, and bacteria to escape into your bloodstream. This triggers an immune response as your body attacks these invaders. Over time, this chronic inflammation and immune system stress can lead to autoimmune conditions.
| The Benefits of Fasting for Immune and Digestive Health You might consider fasting to support the health of your digestive and immune systems. In Fast Like a Girl, Mindy Pelz says that regular fasting improves your immune system in three key ways. First, fasting triggers autophagy. Lowering glucose levels through fasting forces your body to turn to cellular debris as an alternative energy source. This process strengthens cellular health by detoxifying, repairing, and removing damaged components and harmful pathogens. It makes cells more resilient against age-related decline and inhibits viral replication, counteracting degeneration and inflammation that can lead to various health challenges. Second, fasting improves gut health. By allowing the digestive system to rest, fasting reduces gut inflammation, fostering the ideal environment for beneficial bacteria to thrive and spread. This rest phase also stimulates the growth of stem cells that heal leaky gut. According to Pelz, these processes promote a microbial balance that supports your immune system in multiple ways, including enhancing cellular health and glucose regulation. Recent research also suggests that the benefits of fasting on the microbiome extend to our saliva. For example, studies show that the saliva of people fasting during Ramadan has enhanced antibacterial effects, helping people clear COVID-19 from their bodies more quickly. In Super Human, Dave Asprey clarifies how microbial balance supports your immune system. Gut bacteria help maintain the integrity of your gut lining—the barrier between your digestive tract and bloodstream. In addition to fasting, you can improve your gut health by eating more fiber and reducing your exposure to antibiotics and antibacterial products. Third, fasting calms anxiety. According to Pelz, fasting triggers the release of GABA, a calming neurotransmitter that promotes relaxation and emotional stability. This can help reduce the chronic stress that disrupts digestive health. However, Myers doesn’t advocate fasting. Other experts agree, saying that if you’re already diagnosed with an autoimmune condition, such as diabetes, you shouldn’t attempt intermittent fasting. |
Stressor 2: Toxins
Myers explains two ways that toxins can lead to autoimmunity. First, toxins can reduce the production of cells that regulate your immune system.
Second, toxins can confuse your immune system, weakening its ability to distinguish between foreign tissue and your own body. This happens when toxins overstimulate your immune system. It also happens when toxins alter or damage cells in your body so your immune system no longer recognizes them as part of your body.
Environmental toxins come from multiple sources—we’ll discuss four of them. The first source is water containing fluoride and chlorine.
Secondly, environmental toxins are found in toiletries. These products contain harmful ingredients like parabens, phthalates, and heavy metals.
Toxins are also found in a third source: food. For example, food can contain pesticides, heavy metals (especially fish), and chemicals leached from plastic containers and non-stick cookware.
Finally, indoor areas are sources of toxins. Homes can house toxins from building materials, furniture, carpeting, and mold growth. Indoor air can contain chemicals from cleaning products and building materials.
Stressor 3: Infections
In addition to facing toxins, our bodies also face environmental stressors in the form of germs that cause infections. Myers explains that there are two main ways infections can trigger autoimmunity. Your immune system might attack both the infection and similar-looking, healthy body tissues, or it might attack healthy tissue surrounding an infection. As a result, infections may not fully heal and the virus or bacteria may stay in your body, causing chronic inflammation. Some common infections researchers have linked to autoimmunity include the Epstein-Barr virus (EBV) and the E. coli bacteria.
(Shortform note: After Myers wrote this book, a new infection linked to autoimmunity entered the world stage: Covid-19. It can lead to a hyper-inflammatory state that causes the immune system to generate autoantibodies—antibodies that “defend” your body from itself. The resultant tissue damage can release intracellular components that serve as new targets for the immune system, perpetuating the cycle of inflammation and autoimmunity. People who have had Covid-19 have a higher incidence of autoimmune diseases, especially psoriasis, rheumatoid arthritis, and type 1 diabetes. While infections like EBV and E. coli and their effects are well-known, Covid-19 is still relatively new, so its impact on autoimmunity is still being investigated.)
Stressor 4: Emotional and Psychological Stress
Chronic stress that’s unresolved or continues escalating for months or years can lead to an overactive immune system. According to Myers, this shows that humans evolved to handle acute rather than chronic stress. In addition, emotional and psychological stress can depress your immune system, making it more susceptible to infections.
(Shortform note: In The Myth of Normal, Maté shares an example of how a chronic stressor like institutionalized racism can impact physiological health. Institutionalized racism teaches minorities to internalize hate and reject their identities. It teaches this overtly through direct discrimination and subtly through systemic bias and cultural messaging. According to Maté, this enforced self-rejection triggers profound psychological wounds that translate into physiological stress responses. This can lead to biological responses like elevated levels of cortisol and inflammation. Over time, this can contribute to health problems such as heart disease, hypertension, and diabetes among affected populations.)
Stressor 5: Modern Hygiene Procedures
Myers adds that, although they’re lifesaving, modern sanitation and medical practices may contribute to autoimmune conditions by reducing exposure to beneficial bacteria. Factors like being born by C-section, drinking formula instead of breastmilk, and overusing antibiotics deprive children of microbes that help them develop healthy immune systems.
| It’s Possible to Be Too Hygienic Other experts agree that we’ve maybe gone too far in our efforts to protect ourselves from bacteria. Rob Dunn, author of The Wild Life of Our Bodies, argues that there’s a correlation between modern sanitation practices (like using antibacterial soap) and illnesses (like asthma or diabetes). Regular soap washes away harmful bacteria. However, antibacterial soap has extra germ-killing components like triclosan, and it seems to go further than regular soap, killing helpful bacteria that protect us from other illnesses. This effect is similar to how antibiotics kill the bacteria that make you ill, but those antibiotics also kill the good bacteria that live in your stomach. To offset this effect, experts suggest taking probiotics whenever you take antibiotics and avoiding antibacterial soap. In addition, Dunn argues that there might be a connection between autoimmune disorders and the eradication of worms that tend to live in our intestines. Usually, we see getting rid of these worms as a positive development, and there are public health programs all over the world focused on giving children medication to expel worms. However, some studies have found that children who expel worms have more allergies (just like children born by C-section or who aren’t breastfed directly). This suggests that losing the worms weakened their immunity. In addition, populations that have eradicated worms have more cases of Crohn’s disease, an autoimmune disorder. In fact, researchers treating Crohn’s patients with worms are seeing a reversal in many of their symptoms. |
