Lung cancer is a serious health problem and the top cause of cancer deaths in the U.S. each year. Scientists have discovered a few causes for this type of cancer, such as cigarette smoke, but continue to explore other reasons. One factor under investigation is a link between long-term (chronic) inflammation and lung cancer.
What Is Inflammation?
When you get an injury, like a cut to your skin, you may notice that the area gets red and swollen. That’s inflammation, and it’s your body’s normal healing response to an injury. It starts when the damaged tissue releases chemicals. Then, your white blood cells trigger other cells to split and grow to build back tissue and help heal the area.
When the cut is healed up, that’s usually the end of the inflammatory process. This is called acute inflammation.
But there’s another kind: chronic inflammation, which is hidden deep within your body. It can happen even if you’re not hurt, and it doesn’t stop when it should.
Like a scale, your body works to balance between “good” and “bad” inflammation. When this scale tips toward chronic inflammation, it can damage your DNA and, over time, trigger cancer cells. For example, people who have chronic inflammatory bowel diseases like ulcerative colitis and Crohn’s disease are more likely to get colon cancer.
Chronic inflammation affects your whole body, so it’s impossible to pinpoint one specific cause of it. Scientists think ongoing infections, unusual immune reactions to normal tissues, and conditions like obesity may be some possible reasons.
Chronic Inflammation and Lung Cancer
When it comes to lung cancer, experts have homed in on a few things that set off an inflammatory response and raise your chances of getting the disease.
Cigarette smoke
Inhaling cigarette smoke, even if you’re not the one who’s smoking, is thought to spark an inflammatory signal and the creation of cancer cells in your lungs, a process that starts in your genes.
“It’s like lighting a match,” says Stacie Stephenson, DC, CEO of Vibrant Doc and chair of functional medicine at Cancer Treatment Centers of America. “The [cancer-causing] gene is the matchbox, cigarette smoke is the match, and when you put those two together, you cause the fire, which is cancer.”
It doesn’t cause all lung cancers, but experts say cigarette smoking is the top trigger, leading to 80% to 90% of cancer deaths in the U.S.
“Cigarette smoke is kind of a nuclear bomb for the lungs. It does a lot of direct DNA damage and causes a lot of other changes,” says Conor Steuer, MD, an assistant professor of hematology and medical oncology at the Emory University School of Medicine and a lung cancer oncologist at Winship Cancer Institute of Emory University.
But there are things you can do to head off that damage and lower your cancer risk. The most important are to stop smoking and to avoid smoke from other people’s cigarettes, pipes, and cigars.
Other inflammation triggers
But what if you don’t smoke and aren’t around anyone who does? Experts say other less common things in the world around us can also stir up chronic inflammation and possibly lead to certain types of cancer:
- Radon is an invisible radioactive gas released from the normal breakdown of elements in rocks and soil. It’s found in low levels outdoors and higher levels in areas without good airflow, such as mines.
- Asbestos is a group of heat- and corrosion-resistant fibrous minerals used in insulation, fireproofing materials, automotive brakes, and wallboard materials. People who regularly come into contact with asbestos at work are more likely to have lung problems than those who breathe it in at low levels. The federal government now regulates its use.
Researchers are also studying the link between scar tissue, chronic inflammation, and cancer. In infections like tuberculosis, for example, scar tissue can form in the lungs “that continues to have a pro-inflammatory state,” Steuer says.
Medications That May Fight Chronic Inflammation
Certain medications could lower chronic inflammation and your risk of cancer. Scientists have looked at the cancer-fighting effects of anti-inflammatory drugs like aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs), which ease mild to moderate pain and inflammation, but there are no clear answers yet.
“There’s good inflammation as well as bad, and these drugs weren’t specific enough to target that bad inflammation,” Steuer says.
A recent study of the arthritis medication canakinumab (Ilaris) in people who’ve had heart attacks found a surprising result: It may fight chronic inflammation, lowering your odds of getting lung cancer and dying from the disease. But these are early findings, and research is ongoing.
Chronic Inflammation, Diet, Weight, and Exercise
There’s no direct link between lifestyle factors — like food, weight, and exercise — and chronic inflammation and lung cancer. But experts say these things can raise your overall chances of getting cancer and affect cancer recovery. People who routinely exercise and keep a healthy weight tend to get better faster after surgery and other cancer treatments.
Focus on a diet low in saturated fats, animal protein, processed foods, sugar, and carbs. Stephenson calls these foods a “toxic soup that triggers inflammatory processes,” which could, in turn, prompt the formation of cancer cells.
Instead, boost these foods to balance out the inflammation scale:
- Fresh fruit and veggies
- Lean meats like fish
- Nuts and seeds
Exercise and weight loss, if you carry any extra pounds, are also key to lowering your cancer odds, Stephenson says. “Fat cells are more inflammatory than anti-inflammatory.” It’s not always easy to stick to a healthy diet and regular exercise, but “you have to move your body to help your body. It’s never too late to start reducing those risks, and you feel better doing it.”