The Newest Theory of Disease

Inflammation of the ankle.Is inflammation the cause of disease?

This is the newest idea capturing the imagination of medical investigators. We know that heart disease is caused by inflammation of the lining of the arteries. We know that inflammation of the lining in the stomach or small intestine causes peptic ulcer disease. The cause of colon cancer is inflammation of the lining of the colon.

Inflammation is the body’s standard response to irritants. Every medical professional is taught to recognize the signs – the simple flair and wheal – the skin’s redness and swelling after a scratch or bee sting. When an irritant comes in contact with the body, the body reacts with inflammation.

Inflammation releases so many chemicals and proteins, that the outpouring is called a cascade. Some cascades increase blood clotting, others summon white blood cells (body policemen), still others dilate and constrict blood vessels, increase hormone output from the adrenal gland (steroids and epinephrine), the thyroid gland, the pancreas (insulin and digestive enzymes), and the pituitary gland. A host of other proteins serve useful purposes during normal body function but will wreak havoc during a prolonged inflammatory response.

This natural inflammation responds when invaders (irritants – foreign bodies, foreign proteins) have entered the body and must be dealt with. As an acute reaction, it is very effective. But when irritants stay present over a prolonged period of time, the cascades start to get out of control – either becoming tired and not recognizing the invaders (bacteria, cancer cells, or others) or becoming confused and overreacting – attacking normal body proteins (joint lining as in arthritis, pancreatic cells as in Type I diabetes, etc).

Four major body systems are the first to receive outside irritants, outside invaders. These systems get the most exposure to the outside world.

The body’s outside lining, the skin, is the most obvious defense against irritants. It is thick and resistant to attack, only reacting if the tough outer layers of the skin are broken or have been soaked through (poison ivy juice or latex, for example). Even so, some people have sensitive skin that easily reacts to foreign proteins. We say these people are allergic. Their skin overreacts to invaders which most people’s skins ignore.

The body’s inside lining, from the mouth to the anus, is also bombarded constantly by foreign proteins and particles that can attach to normal body proteins. The gut’s lining is very thin, to facilitate absorption of digested nutrients. The gut is flushed out on a regular basis by the large volume of water it secretes. But a slow or irregular flush cycle can leave it exposed to foreign particles causing inflammation.

The body’s breathing system, the throat and lungs, is the next obvious area. Their lining is thin to take in oxygen and release carbon dioxide. Its protective mechanism is a lining of small, ever-waving hair-like projections – called cilia – that move irritants up and out of the lung or down and out of the nose, sometimes producing a cough or a sneeze to expel them. Irritating proteins can produce lung spasms, which is known as asthma.

The body’s blood vessels are just underneath the other three systems. Blood vessel linings are thin to let in nutrients and oxygen. The blood’s actual flow is this system’s only natural cleansing mechanism. Blood vessels have to rely solely on the white blood cells to seek out and destroy invaders. In the meantime, the blood vessels are at the mercy of inflammation.

Why discuss this topic in a column normally focused on disease prevention?

Because this information is the foundation for the next post, “Inflammation – Part II” – on what to do about prolonged, destructive inflammatory responses.