Updated on 1/24/2005
We're all familiar with aspirin as an inexpensive, over-the-counter remedy for headaches, fevers and the aches and pains of arthritis, but researchers keep discovering new effects for this remarkable drug. You may not be aware that aspirin is a semisynthetic derivative of white-willow bark. A century ago chemists created it by making a small chemical change in salicylic acid, a natural constituent of willow (Salix). Willow-bark tea was - and is - a folk remedy for pain among Native Americans and Europeans. Its active component, salicylic acid, is too irritating to the stomach. Acetylsalicyclic acid - aspirin - is both less irritating and more potent as a pain reliever.
Over the years, researchers have discovered more and more effects of aspirin: it reduces the risk of heart attacks and strokes by preventing platelets from clumping, thereby reducing the chances that blood clots will form and clog blood vessels. It reduces the risks of colon, esophageal, and lung cancers. It may reduce the risk of Alzheimer's disease. It probably works all this magic by regulating the production of endogenous hormones that control inflammation and cell proliferation.
You may get the maximum effect from as little as 81 milligrams of aspirin daily, about one-quarter the amount in a standard tablet, although there is some uncertainty about the ideal dose. I currently take 162 milligrams, two low-dose tablets or half a regular tablet. Joe Alpert, M.D., chairman of the Department of Medicine here at the University of Arizona, notes that any dose from 81 to 325 mg daily can be effective but that the current consensus is 162 mg. Those with a history of gastrointestinal bleeding should be cautious about taking aspirin; otherwise, I think any adult can use it safely. Children and teenagers should not take aspirin because of the danger of Reye's Syndrome, a potentially fatal illness that frequently develops after a viral infection and is associated with the use of aspirin.
I recommend taking a low-dose aspirin daily to many patients and friends. I regard low-dose aspirin as a tonic and preventive that everyone should consider, particularly those who are at risk of any of the diseases mentioned above.
Andrew Weil, M.D.