What is it about women that incidences of autoimmune disease raise to upwards of 78% of the population affected? Why is it that males do not get many autoimmune diseases? What is the difference between men and women? (Haha, such a loaded question. The infamous book, Men are from Mars, Women are from Venus , may give some insight! Just kidding…sort of.)
The Merriam-Webster definition of “autoimmunity” is: “a condition in which the body produces an immune response against its own tissue constituents” (1). The actual origin of auto-immunity is highly debated among the medical community and can occur anywhere from incidences of viral/bacterial infections, genetic predisposition, food allergies, gastrointestinal dysfunction, or systemic inflammation of the body. Sex hormone differences also contribute to the mechanism of autoimmunity in women more often than men.
How do infections cause autoimmunity? For people with any autoimmune condition, there is a tendency for the immune system to be exacerbated in response to any stimuli. Viruses and bacteria normally stimulate an immune response, and when the system is already malfunctioning, cross reaction with human proteins (from recognizing viral and bacterial antigens) can stimulate tissue self-destruction.
How does genetics cause autoimmunity? This comes back to the old-age question: nature versus nurture. Depending on our genetic inheritance and our environment indicates which genes are expressed, and which are repressed, or selectively not expressed. If a certain autoimmune trait is carried within a family lineage, then future generations can carry this gene and/or carry it throughout the population. If a person is exposed to the same stimuli (food, water, air, pollution, stress, emotions, etc) as their ancestors who have a similar disease, then propagation of the auto-immunity is within the population.
How do food allergies, gastrointestinal issues, and systemic inflammation cause autoimmunity? Old school Naturopaths/Nature Cure doctors have always said to “treat the hole in the middle of the body,” meaning the gut. When there is inflammation in the body from eating pro-inflammatory foods (high fructose corn syrup, meat, dairy, wheat, eggs), then the digestive tract begins to have holes within its lining. Normally within the gut there are very small holes allowing for extremely small food particles to pass through to be absorbed into the blood stream. The more inflammation in the body, the larger the holes in the gut become, and larger food particles pass through into the tissue space. This allows a perfect storm for the immune system to react to these large “foreign” particles (that would have normally been broken down by functional digestion) and create antibodies to them. Antibodies are the body’s defense mechanism to target a certain foreign molecule and “tag it” to be attacked by other white blood cells. The more that we eat a certain type of food, the more reactive that we become to it, which may also propagate a cross-reaction with a person’s own tissues, which therefore creates an autoimmune condition.
Finally, sex hormone differences can cause autoimmunity in women because of the presence of estrogen and a “more sophisticated” heightened immune response. There are 3 types of estrogen within the body: estrone (E1), estradiol (E2), and estriol (E3). Estrone is most predominant in menopausal women. Estradiol is most prevalent in men and women who are not pregnant. Estriol may be present in pregnant women, as well as post-menopausal women predominantly. It is known that during pregnancy, disease courses of autoimmune conditions may come on, or may change significantly, which may be due to a shift in prevalence of different estrogen levels during this time.
Estrogen does play a role in cellular differentiation, even regarding the immune response. There are many cellular messengers (called cytokines and interleukins) that allow cell to cell communication between tissue cells and cells of the immune system. A general rule is that T cells of the Th1 line are pro-inflammatory by stimulating a cellular response, while T cells of the Th2 line are “anti-inflammatory” by stimulating an antibody response. It is postulated by some medical circles that alterations in estrogen (during pregnancy or even during a female’s menstrual cycle) has implications in a shift towards the Th1 line, creating a more inflammatory immune response picture, which would also set the scene for autoimmunity to develop.
The most common autoimmune conditions in women include
> Hashimoto’s thyroiditis
> Systemic Lupus Erythematosus (lupus)
> Rheumatoid arthritis
> Sjogren’s syndrome
> Multiple sclerosis
(to name a few)