It's not necessarily a bad idea although it won't have much effect on either lipid levels or blood pressure. One benefit of daily aspirin is that it slows clotting. The Amer. Heart Assn. recommends a daily aspirin for all persons who have had a heart attack unless there is some reason they cannot take aspirin. Other studies have indicated that taking aspirin might help prevent colon cancer. Aspirin can cause serious injury to the stomach lining giving rise to internal bleeding and because of it's blood thinning action, can increase the risk of stroke caused by bleeding in the brain. But for some individuals it may actually help prevent a stroke. In any case, the full daily 325 mg dose may not be necessary; rather, a daily 81 mg dose (so-called "baby" aspirin size) may be all that is needed to derive the heart disease prevention benefits. Confusing, no? Bottom line is that one probably should start a daily dose of aspirin only on advice of one's physician. Although it's a very old drug, it's still a drug nevertheless, with potential undesirable side effects.