Inflammation at the root of many common diseases
Burn yourself? Trip and scrape a knee? Catch a cold? In a rapid-fire defensive response to injury, your body is primed to kick instantly into action, releasing a cascade of chemical messengers called cytokines to overcome foreign invaders, such as bacteria and viruses, and heal your body.
Leo Galland, MD, director of the Foundation for Integrated Medicine in New York City, explains that this complex series of chemical and physiological reactions plays an important role in the recovery from injury and protection from infection. However, he adds, more and more research indicates that in many instances, the defense response spirals out of control, causing inflammation and triggering disease. New research is finding inflammation implicated in an array of diseases from heart disease to cancer to Alzheimer's.
A NEW VIEW OF HEART DISEASE
For years, cardiovascular disease was seen as a plumbing problem. Over time, fatty deposits composed of LDL, the "bad" cholesterol, built up in arteries and eventually clogged them -- much like sludge builds up and clogs the pipes underneath your sink. When the artery opening became blocked and no blood could pass through, the person had a heart attack.
More recently, doctors have come to realize that while cholesterol is a significant factor in heart disease, it is by no means the only one -- and may not even be the most important. The new thinking is that inflammation of the arteries plays a major role in heart disease, says Dr. Galland. This may solve the mystery of why half of heart attack victims have normal (or even low) cholesterol.
When excess fat in the blood builds up as plaque within heart vessel walls, an inflammation alarm is triggered, causing immune cells known as monocytes to rush in and attach to the plaque. Monocytes soon grow into macrophages, which begin devouring the fatty plaque. This immune activity causes the liver to release C-reactive protein (CRP), which joins in the attack on the growing plaque. Plaque becomes increasingly unstable and eventually can rupture, leading to a heart attack.
A RISK FACTOR FOR CANCER
When a person has inflammatory bowel disease, he/she is at an increased risk for colon cancer. Other causes of inflammation that can lead to cancer include viral infections (such as hepatitis)... chronic heartburn (where the esophagus is continually assaulted with stomach acid)... and exposure to asbestos, air pollution or cigarette smoke, which causes irritation and leads to inflammation. The longer the inflammation persists, the higher the risk for cancer.
The theory is that the body's immune system produces agents that cause normal cells to become cancerous. Macrophages and other inflammatory cells produce oxygen-free radicals, highly reactive substances that damage other cells, including DNA. This can lead to a genetic mutation that enables the damaged cells to continue growing and dividing. To the immune system, this damage appears like a wound that requires fixing. Immune cells rush in, bringing along with them growth factors and other proteins -- but instead of healing a wound, they end up feeding an abnormal growth.
INFLAMMATION AND ALZHEIMER'S DISEASE
Studies also indicate that inflammation plays a role in age-related illnesses such as Alzheimer's disease. At the University of California in San Francisco, researchers studied the blood samples of more than 3,000 seniors for three known markers of inflammation -- interleukin-6 (IL-6), CRP and tumor necrosis factor. They repeated the same tests two years later. At both times, participants were also given a battery of cognitive function tests.
Researchers found that seniors with the highest levels of inflammation (those whose blood levels of IL-6 and CRP were in the upper one-third) had substantially more cognitive decline than those with blood levels in the lowest one-third. These results were published in the journal Neurology in 2003.
HOW TO CONTROL INFLAMMATION
The diseases we've looked at here are just the tip of the iceberg. Chronic inflammation has long been known to play a role in such inflammatory diseases as arthritis, asthma, allergies, skin diseases and assorted autoimmune diseases. Dr. Galland observes that more recently, low-grade inflammation has also been seen as a factor in such conditions as obesity, type 2 diabetes and high blood pressure.
The following strategies can help reduce your risk for inflammation-related problems...
· One of the best weapons against inflammation is low-dose aspirin, says Dr. Galland. As a type of drug known as a salicylate, aspirin not only discourages blood clotting, it also helps to turn off the genes that promote inflammation and prevents the manufacture of inflammatory hormones called prostaglandins.
· Dr. Galland recommends a diet rich in inflammation-fighting antioxidants from fruits, vegetables, nuts and seeds. He points out that antioxidant effects are greatest from food, noting that there are a mixed set of responses from antioxidant dietary supplements. In addition, Dr. Galland says that vegetables and fruits naturally contain salicylates.
· Eat fish three times a week. Deep-water fish, such as wild salmon, mackerel and sardines, are rich sources of anti-inflammatory omega-3 fatty acids. If you don't get enough omega-3 fatty acids in your diet, Dr. Galland recommends fish oil supplements that supply up to 1,500 mg of DHA daily.
· Avoid foods that are high in saturated fat, trans fats and cholesterol, such as red meat, french fries and other fast and processed foods. These increase your risk for inflammatory disease.
· Maintain a healthy weight. Dr. Galland says that obesity increases the inflammatory response in the body, which explains why it is linked with so many chronic inflammatory diseases.
· Exercise is key, notes Dr. Galland. Elevated CRP is associated with a two- to fivefold increase in the risk for heart attack. Studies show that exercise dramatically decreases CRP levels.
· In cases of cardiovascular disease, Dr. Galland notes that the cholesterol-lowering drugs called statins may be helpful, though the risk associated with taking them must also be considered. Recently, scientists proposed that statins are effective against heart disease not only because they lower cholesterol, but because they have a significant anti-inflammatory effect. When plaque is inflamed, it is more likely to rupture and cause a heart attack.
· See your health-care professional for a physical examination once a year. If you are at risk for inflammatory disease because of health concerns (such as obesity, high blood pressure or diabetes), family history or negative lifestyle habits (such as heavy drinking or cigarette smoking), get tested for inflammatory markers, such as CRP.
Also, seek counseling to get yourself on a healthier path to wellness.
· Leo Galland, MD, director, Foundation for Integrated Medicine, New York City.
· Alzheimer's Association, www.alz.org
· American Cancer Society, www.cancer.org
· American Heart Association, www.americanheart.org
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