More than 24 million Americans have an autoimmune disease, and that number is climbing. When researchers in North Carolina examined 14,000 Americans between 1991 and 2012, they discovered that the prevalence of antinuclear antibodies, an early marker of autoimmunity, had increased by 45 percent. Another study — this one spanning three decades — found that autoimmune diseases of the joints, glands and digestive system are rising at a steady 3.7 to 7.1 percent each year. Smoking and being overweight are two risk factors within your control that are associated with greater risk of RA, one of the most common autoimmune disorders, which affects the lining of your joints.
Food allergies. This is an immune system overreaction that can occur immediately after eating something as seemingly benign as a peanut butter and jelly sandwich. Food allergies now afflict more than 1 in 10 adults, according to a Northwestern University study of 40,000 people. Rates are particularly high for shellfish, milk and nut allergies, and the number of people who have them has been climbing steadily since the 1980s. “We’re now more susceptible to responses against harmless stuff that shouldn’t be a big problem for our immune system,” Ansel says. “But instead we generate these big and often destructive responses.”
So what’s causing the confusion in the immune system? To a large extent, it’s our changing environment.
“Our bodies deal with thousands of chemicals that were not in the environment 50 years ago — and some not even 20 years ago,” says Aristo Vojdani, a clinical immunologist and adjunct associate professor in the Department of Preventive Medicine at Loma Linda University. Heavy metals and industrial pollutants are among the top offenders, but pesticides, preservatives and compounds in food can also alter immune function. All told, the Centers for Disease Control and Prevention (CDC) counts more than 300 environmental chemicals that reach measurable levels in our bodies.
“Exposure to different environmental insults can add up and alter how the immune system functions,” says David Shepherd, a professor of environmental immunology at the University of Montana. “In some cases, [the chemicals] are immune-activating,” meaning they cause inflammation, “and in others, they’re immunosuppressive,” which makes you susceptible to attack.
Add to that a general decrease in physical exercise, ever-increasing levels of stress and, yes, our increasing age. All these many factors have laid siege to our immune system like never before.
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Get to know your immune system
When bacteria and viruses enter your body, these natural defenders spring into action
This gargantuan white blood cell lies in wait within healthy tissue. Sometimes years pass without action, but when a pathogen emerges, macrophages release a blast of proteins called cytokines, which calls the immune system into battle. From there, the macrophage joins the cleanup crew by gobbling up dead and crippled pathogens.
Natural Killer Cell
Some infected cells can be rendered “invisible” to the immune system, which allows the pathogen to continue to spread unabated. That’s when natural killer cells provide an extra layer of defense. A natural killer cell has the ability to identify abnormal cellular appearance — as is often the case with cells infected by a virus. The killer cell studies its mark, and if the suspect cell appears to be infected, it releases proteins near the suspected pathogen. The pathogen then eats the protein — a fatal, final meal.
At the first sign of trouble, neutrophils swarm like killer bees with multiple stingers. Neutrophils can capture their enemy, set traps, inject poison and amplify signals that pull in more immune-system warriors. Neutrophils only live for about a day, but as long as the battle continues, fresh cells keep showing up to fight. Unfortunately, in their frenzy, they can often mistake healthy cells for the enemy. When that happens, and the neutrophils attack healthy tissue, the result is inflammation, and inflammatory diseases, throughout the body.
Although B cells don’t kill invaders directly, they help to slow down pathogens by covering them with sticky Y-shaped proteins, robbing them of their strength and making them easy targets for cells like macrophages, which eat them in clumps. The B cell is an adaptive immune cell, meaning it is highly effective against diseases it has battled before but struggles to recognize new pathogens. When a novel coronavirus arrives, it takes time to ramp up production of antibodies.
The T cell is one of the special-ops white blood cells called upon to “recognize” a foreign invader and know exactly how to fight it off. With new enemies like COVID-19, however, the process can take weeks. Once the T cell learns the code — essentially mapping the molecular structure on a pathogen’s surface — it quickly trains an army of T cells to begin opening infected cells and pumping them full of toxins. Doctors call this process immunity, although with COVID-19, we still aren’t certain how long it lasts.
This content was originally published here.