We used aspirin for the better part of a century before we understood how it worked. People had been using its forerunner, salicin, to treat pain for more than 2,400 years, by simply chewing the bark of a white willow tree (genus Salix). Early in the 19th century, chemists produced a simpler version called salicylic acid. It reduced fever but a dose strong enough to bring down a raging fever was also strong enough to begin eating away the lining of the stomach.
In 1897 a young chemist working for the German company Bayer found a more efficient way to attach an acetyl groupa hook-shaped tail of carbon and oxygen atomsto salicylic acid, making acetylsalicylic acid, the aspirin we use today. The drug sat on the shelf at Bayer for more than a year because it was believed that acetylsalicylic acid, like salicylic acid, "enfeebled" the heart. Testing revealed that it was highly effective as a pain and fever reducer, however, and Bayer put it on the market under the name aspirin.
In the 1950s, a doctor named Lawrence Craven had found that a daily dose of aspirin seemed to prevent the building up of blood clots in the arteries that supply the heart. He prescribed aspirin to 8,000 patients over the years, none of whom died from coronary thrombosis, but he published his results in an obscure journal and his findings were largely ignored or discounted because of his methodology.
A major study found aspirin may reduce the risk of a first heart attack by 44 percent. Other studies have shown that it can lower the risk of a second heart attack by 30 percent. There's much more to the story, however. Research has shown that aspirin may reduce the risk of colon cancer by 40 percent; esophageal cancer to 80 to 90 percent; and ovarian cancer by 25 percent. Aspirin may even slow dementia and Alzheimer's. Even with these promising findings, aspirin's possible side effects make the question of whether to take aspirin regularly one to be discussed with a physician.
The drug companies are working to minimize these harmful side effects. But it would seem that aspirin, perhaps the most common item in medicine cabinets, is something of a miracle drug itself. We've come a long way from chewing willow bark.