I'm not a fan of aspirin. It causes serious bleeding problems and there are much safer alternatives. Still, millions of people take aspirin every day to prevent heart attacks, strokes, and blood clots. True, it does thin your blood. But you may not get even the limited benefits of aspirin if you take another pain killer at the same time.

A recent study showed that you shouldn't take certain NSAIDs (such as  ibuprofen and indomethacin) with aspirin. The researchers said the NSAIDs neutralize the clotting effects of aspirin when you take them at the same time. NSAIDs compete with aspirin for the enzyme pathway called Cox-1. Other drugs of the same class, such as rofecoxib, diclofenac, and acetaminophen, did not block the aspirin activity.

But don't think you can take acetaminophen (Tylenol) with aspirin and avoid side effects. The New England Journal of Medicine showed many years ago that acetaminophen and aspirin increases your risk of chronic kidney failure. In fact, it increases your risk by two-and-a-half times more than Tylenol alone.

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So even if acetaminophen doesn't block the blood-thinning effects of aspirin, you don't want to take the two together. In fact, if you're on aspirin for any reason, do not mix it with any other NSAID drugs. At best, you're voiding the blood-thinning effects of the aspirin.  At worst, you're opening the door to some nasty side effects - some we may not even know about yet.

But ask yourself this: Why take aspirin at all? Omega-3 fatty acids, such as fish oil, flaxseed oil, and hemp seed oil, have the same heart-protecting effect as aspirin. And they don't cause any bleeding in your gut or interactions with other painkillers. They also can reduce your cholesterol, which aspirin doesn't do.