The Body's New Bad Guy
Heart disease and cancer, the two most deadly killers of our time, are each affected by an immune response that may play a key role in a host of chronic diseases, researchers say.
That immune response is inflammation.
Inflammation is normal and necessary to fight off a sinus infection or help heal a cut. Yet at times it can soar out of control, causing severe illness and death. The process that makes inflammation run amok is complex. It seems to vary with the trigger and the part of the body it invades.
"Our appreciation for what inflammation can do is growing," says Carl Nathan, Ph.D., a New York immunology expert. "In many ways, we have an epidemic of chronic inflammation."
New way of thinking
Heart disease is an example, he says. Doctors used to think of atherosclerosis, the hardening and narrowing of arteries, as a problem with the way the body stores fats in the blood. "Now, we know it's a consequence of chronic inflammation," he says.
In heart disease, chronic inflammation damages the inside of coronary arteries and leaves them prone to plaque that clogs the blood vessels. That leads to clots that cause heart attacks. "It's a cascade of events, but inflammation sets up an environment for the cascade to occur," Dr. Nathan says.
Chronic inflammation also plays a role in some cancers, diabetes, asthma, rheumatoid arthritis, osteoarthritis, lupus, ulcerative colitis, Crohn's disease, Barrett's esophagus, macular degeneration, and obesity. It shares the blame for central nervous system disorders such as multiple sclerosis, Alzheimer's disease, and Lou Gehrig's disease, says Richard M. Ransohoff, M.D., a Cleveland researcher on neuroinflammation. "In some diseases it's a prime mover and in others it plays a lesser role," he says.
What researchers learn as they study inflammation in one illness may shed light on an illness that at first glance seems unrelated. "There may, indeed, be a time when there are doctors who study and treat only inflammation," Dr. Ransohoff notes.
"The thing about inflammation," Dr. Nathan adds, "is that it's on the verge of happening all the time. It's a kind of license to kill, but something restrains it, and we need to learn much more about that mechanism."
What you can do
What can you do to reduce the risk that inflammation may lead to heart disease, cancer, diabetes, or some other chronic illness?
First, find out if you already have chronic inflammation. Ask your doctor about a blood test for C-reactive protein, which can show if you might have chronic inflammation. The test, which costs about $50 and is covered by some insurance plans, was recently improved. "We know that a high C-reactive protein is an indicator for increased risk for a heart attack," Dr. Ransohoff says. Researchers are weighing how that test might help gauge risks of cancer and other ailments.
Work with your doctor to prevent and control infections and autoimmune disorders such as rheumatoid arthritis. Both can lead to increased inflammation. That, in turn, may cause heart disease and cancer.
Eat a nutritious diet and get exercise. Overeating can set off the inflammatory process, which may play a key role in obesity. Exercise releases proteins that fight inflammation.
Reduce stress. High stress levels cause C-reactive protein to spike, says Robert Genco, D.D.S., Ph.D., a Buffalo specialist in oral biology and microbiology. Dr. Genco has studied the links among diabetes, heart disease, and gum disease for more than 25 years. The infection from gum disease "causes a hyperinflammatory response that appears likely to affect some systemic illnesses, especially diabetes," he says.
Ask your doctor if a daily low-dose aspirin is right for you. Aspirin may help stave off a heart attack and colon cancer. Ask whether a fish oil supplement might help, too. A study released in 2007 looked at 22,500 postmenopausal women. It found that those who took a daily low-dose aspirin were 16 percent less likely to have cancer than those who did not take aspirin.