Managing your body’s immune response is key to diseases of aging.
Originally published by Mike Zimmerman, AARP, Updated January 17, 2020
It hardly sounds serious at all. An inconvenience, perhaps, like maybe a mild fever or a creaky joint. In the lexicon of aging and disease, there are far more worrisome words: cancer, heart disease, dementia, diabetes. But researchers have suspected for years that all of these health issues, and more, have at their heart one common trigger: low-grade inflammation. And now they may finally have proof.
Cardiologists in Boston have reported on a clinical trial with more than 10,000 patients in 39 countries (mean age: 61) that tested to see if an anti-inflammatory drug could lower rates of heart disease. They discovered that it could. But they also found that the same drug, canakinumab, reduced lung cancer mortality more than 77 percent, and reports of gout and arthritis (conditions linked to inflammation) also fell.
“Inflammation plays a role in everyone’s health,” says Dana DiRenzo, a rheumatologist and instructor of medicine at Johns Hopkins University School of Medicine in Baltimore. When inflammation levels increase, so does the risk of disease. But understanding inflammation can be tricky because, when you get a disease, inflammation levels naturally increase as your body fights the condition. Inflammation, in other words, is both good and bad.
Given how crucial this issue is to your health, AARP spoke with some of America’s top experts in the field, pored over the latest studies and created this guide to understanding — and overcoming — inflammation.
What exactly is inflammation?
Think about when you catch the flu and your body temperature rises to fight the virus. That’s a form of inflammation. So is the redness and swelling that occur when you sprain your ankle; it’s the process your body uses to provide the healing chemicals and nutrients needed to help repair the damage.
These are examples of acute inflammation, a temporary, helpful response to an injury or illness. Once the danger goes away, so does the inflammation.
Chronic inflammation, on the other hand, is a slow, creeping condition caused by a misfiring of the immune system that keeps your body in a constant, long-term state of high alert, says Robert H. Shmerling, clinic chief in the department of rheumatology at Beth Israel Deaconess Medical Center in Boston.
It’s often the chronic inflammation, not the viruses themselves, that causes much of the damage.
Why is chronic low-grade inflammation a problem?
“Over time, inflammation damages healthy cells,” says Roma Pahwa, a researcher for the National Institutes of Health who specializes in the inflammatory response. Here’s why: When cells are in distress, they release chemicals that alert the immune system. White blood cells then flood the scene, where they work to eat up bacteria, viruses, damaged cells and debris from an infection or injury. If the damage is too great, they call in backup cells known as neutrophils, which are the hand grenades of the immune system — they blow up everything in sight, healthy or not. Each neutrophil has a short life span, but in chronic inflammation, they continue to be sent in long after the real threat is gone, causing damage to the healthy tissue that remains. The inflammation can start attacking the linings of your arteries or intestines, the cells in your liver and brain, or the tissues of your muscles and joints. This inflammation-caused cellular damage can trigger diseases like diabetes, cancer, dementia, heart disease, arthritis and depression.
And because it’s low grade, “its slow and secret nature makes it hard to diagnose in day-to-day life,” Pahwa says. “You have no idea it’s even happening until those conditions show symptoms.”
How can something natural to our bodies be so toxic to our health?
“It can be complicated to figure out if inflammation is friend or foe,” Pahwa says. Looking at the four main causes of chronic inflammation, however, sheds some light.
An outside infection that’s hard to kill: You contract a chronic infection like hepatitis C or Lyme disease that lingers in the body for a long time. Your body responds with inflammation that also lingers a long time. In fact, it’s often the chronic inflammation, not the viruses themselves, that causes much of the long-term damage related to these diseases.
Genetics: You inherit a genetic propensity toward a health issue. In some cases, the genes related to these health issues can be turned on by inflammation: Diabetes and cancer are two genetically related diseases that can be triggered by inflammation. In other cases, the gene itself causes a misfiring of the immune system that causes the inflammation in rheumatoid arthritis, multiple sclerosis, lupus and other diseases.
Environment: Pollution, air and water quality, environmental allergies and a host of other environmental factors can trigger and sustain inflammation.
Lifestyle: Obesity, unregulated stress, tobacco use, drinking too much, lack of physical activity, lousy sleep and, of course, poor diet are all linked to chronic inflammation.
And getting older increases inflammation, too?
Unfortunately, yes. The older we are, the more exposure we’ve had to stuff like environmental toxins, stress, alcohol, bad foods and chronic diseases. Plus, aging makes it more difficult for our bodies to properly manage our immune systems, to extract nutrients from food and to shed extra pounds. “There are thousands of articles in the science literature related to aging and inflammation,” says Thomas Buford, an associate professor with the University of Alabama at Birmingham School of Medicine’s division of gerontology.
So what makes chronic inflammation happen?
Chronic inflammation is a cascading effect of reactions in the body, Pahwa says. Here’s a (very) basic breakdown of what’s going on.
Something triggers the immune system. Whether it’s a chronic disease, an autoimmune disorder, weight gain, psychological stress, poor nutrition, exposure to chemicals or allergens — something puts your body in a state of stress and keeps it there.
The immune system responds. The body goes into attack mode with its inflammatory response, which also includes blood vessel expansion to increase blood flow to the problem areas. Blood is the primary delivery system for all these substances.
And responds … and responds … and responds. An endless cycle of pro-inflammatory foods, rampant stress, bad sleep and more keeps this process in constant motion because we never give the body a break.
There are “pro-inflammatory foods”?
Yes, and they’re the same foods you’ve been warned about by everyone from your dentist to your cardiologist. (And that’s no surprise, because gingivitis and sclerotic arteries are both inflammatory conditions.) Foods high in sugar or high in unhealthy fats (think deli meats and fried foods) are top of the list.
“We don’t fully understand it yet,” Buford says, “but now we know our gut microbiome, made up of trillions of bacteria, influences physiologic processes throughout the body.” We’re born with a balance between good and bad bacteria in the gut. When that balance is thrown off — known as dysbiosis — it can lead to trouble. “A disregulated microbiome has been associated with metabolic diseases, pulmonary diseases, nervous system conditions, Alzheimer’s — and these associations grow as we learn more and more,” Buford says.
