It’s partly in your genesMonkey-Business-Images/Shutterstock
The research we do have suggests it might be a combination of genetics and an environmental trigger that brings on an autoimmune condition, Dr. Cihakova says. Interestingly, families could have a genetic susceptibility to autoimmunity in general, so one family member might have type 1 diabetes while another has lupus, and yet another has rheumatoid arthritis. But it’s not just about genetics. “Studies on twins show that genes alone cannot explain why certain individuals develop autoimmune diseases,” says Dr. Cihakova. “It is possible that genetically susceptible individuals develop an autoimmune disease after a certain infection, as multiple viruses have been suspected to precede autoimmune diseases.” Could an autoimmune vaccine be on the horizon?
Environmental factors could be triggersAfrica-Studio/Shutterstock
Or, something outside the body could switch on the autoimmune response. “The rapid increase suggests that environmental factors play a role—a notion also supported by the fact that the increase in incidence of autoimmune disease is evident in recent migrants to western countries,” Dr. Cihakova says. In other words, studies show people who move to a western country end up with the same autoimmune rates as people who were born there. Environmental risk factors range from ultraviolet radiation and asbestos to solvents in cleaning products and nail polish. “Silica dust [from working with quartz, granite and other minerals] and smoking are two risk factors for autoimmune disease,” Dr. Somers says, as a recent review from the National Institutes of Health found. “Mercury is another toxicant that has been suggested to play a role in autoimmunity.” A study from the University of Michigan found that mercury from eating large fish like swordfish, and to lesser amounts tuna, salmon, and other seafood, correlated with higher autoimmunity—even at levels considered safe. Here’s why autoimmune and other health problems can feel worse during summer.
So many theories for autoimmunityAkarat-Thongsatid/Shutterstock
Another theory for autoimmunity’s rise is the “hygiene hypothesis,” which suggests that in developed countries we’ve gotten so good at fighting off germs through cleanliness, vaccines, and medicine that our bodies have become out of whack and forget what they’re supposed to attack. “Some researchers believe this health trade-off is no coincidence, and suggest that the decrease in acquiring natural infections has caused the increase in allergies and autoimmune disorders,” Andrew Weil, MD, an integrative immunologist at the University of Arizona, wrote on his blog. Another theory is that we’ve messed up the bacteria in our gut through eating too much refined and processed food in our western diet—which could account for the rise in gluten allergies and celiac disease. “The bacteria in the gut regulate the immune system heavily,” Robin Berzin, MD, of Parsley Health, told Huffington Post. Read about seven signs you have leaky gut syndrome.