Inflammation may have its place in the healing runner.
Though NSAIDs inhibit an enzyme called cyclooxygenase (COX) and reduce inflammation, many practitioners argue that inflammation is not just a sign of injury; but a necessary component of the healing process. Inflammatory cells, which rush to the scene when a ligament, tendon or muscle is injured, remove debris and recruit growth factors called cytokines. By preventing the natural inflammation that occurs right after injury, NSAIDs may even slow down the healing process.
Furthermore, as Running & FitNews editorial board member Stephen M. Perle, DC, MS, points out, "Certain sports injuries, 'tendinitis' in particular, are not inflammatory in nature. In fact, the lack of inflammation, the first stage in the healing process, is the problem."
The latest on colon cancer
But recent evidence that inflammatory enzymes have a hand in cancer development further complicates the discussion of what role COX inhibitors should take in the prevention and treatment of various diseases and injuries.
In March, reports emerged extolling more benefits of a daily dose of aspirin. Researchers at Dartmounth-Hitchcock Medical Center looked at 1,084 patients with a recent history of colon polyps, and found that the recurrence of polyps--the likelihood of which is increased in people who have previously had them--was reduced by 19% in patients who took a baby aspirin daily.
While these researchers reported no change in colon polyp recurrence in those who took a standard dose (325 mg), a second study of 517 patients found that this higher dose made polyp recurrence 35% less likely than for patients in a second, placebo group. Not only was the rate of polyp recurrence 10% lower in the aspirin group, the average number of polyps was lower, and the time to detection of the first polyp was longer. Further research is called for to explain the ineffectiveness of the higher dose in the first study.
Aspirin has been shown to reduce the risk of heart attacks by virtue of its blood thinning properties. People at risk for stroke, or with a history of coronary artery disease, high cholesterol or hypertension can benefit from a daily dose. However, a daily dose of aspirin can significantly increase the risk of gastrointestinal bleeding in runners, because their blood is more often than not already sufficiently clot-free. Never begin a daily dose of aspirin without consulting your doctor.
The COX enzyme that aspirin and NSAIDs block ordinarily acts to form prostaglandins, substances found in abundance in many types of cancer cells. Many researchers therefore believe the prostaglandins that aspirin and NSAIDs inhibit are involved in the development of cancer. If a causal link between these substances and cancer growth is firmly established in the future, aspirin's role could become very significant in the prevention of many types of cancer, including throat, lung, stomach, breast and colon cancers--particularly because it remains the less controversial medication.
Less may be more
Part of the controversy surrounding NSAIDs are their rather serious side effects. They can cause dangerous gastrointestinal tract bleeding. Worse, possibly due to their analgesic effects, only 40% of those who have NSAID-induced GI bleeding report abdominal pain before they bleed. This makes screening difficult.
Marathoners and other endurance athletes have an additional cause for concern, as they are often chronically dehydrated. Decreases in renal blood flow, another side effect of NSAID use, combined with dehydration, can lead to acute renal failure. NSAIDs partially block the secretion of sodium, a further complication for runners.
(NEJM, 2003, Vol. 348, No. 9, pp. 879-880, 883-899; Phys. & Sportsmed., 2003, Vol. 31, No. 1, pp. 35-40; JAMA, 2003, Vol. 289, No. 9, http://jama.amaassn.org; Gastroenterology, 2003, Vol. 124, No. 2, pp. 544-560)
RELATED ARTICLE: Screening for Safety
Nothing can substitute for regular screening and surveillance of colon cancer, especially for those age 50 and older. The U.S. Multisociety Task Force on Colorectal Cancer recently spoke out on the importance of initial screenings in particular. They call the first test especially important because it detects the largest, most dangerous polyps, and helps get patients in the habit of screening. Even though about 93% of all colorectal cancers occur in people 50 and over, screening rates in this age group are surprisingly low.
In a 2001 report on trends in colorectal cancer screening, the Centers for Disease Control and Prevention estimated that in 1999 only 20.6% of U.S. men and women age 50 and older reported having had a fecal occult blood test in the year preceding the survey; and only 33.6% reported having had a sigmoidoscopy or colonoscopy within the past 5 years. This underuse of screening frustrates the medical community because the likelihood of surviving colorectal cancer greatly increases if the disease is treated early, and the screening procedure is covered by Medicare. If your family has a history of colon cancer, ask your doctor about an initial screening as much as 20 years prior to reaching this age group.
(Centers for Disease Control and Prevention, www.cdc.gov)
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|Title Annotation:||You & Your Body|
|Publication:||Running & FitNews|
|Date:||Nov 1, 2003|
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