Timothy,
Not quite answered, but QDM's "non-answer" is actually the best.
Of course the decision to take aspirin (or any drug) depends on a risk/reward analysis as suggested by others. But two apparently healthy people can be at different risk.
So, for instance. Healthy people over 50 are at higher risk of heart disease than healthy people under 30. And healthy people over 50 are at higher risk of aspirin side effects
Current thinking is that if you are at higher than 1% risk of having a heart attack a year, you should take Low Dose Aspirin.
Plenty of cardiologists are also asking the same question. My non-interventionalist mates on the front line tend to want to put an aspirin/statin combo in the drinking water. I take it when I remember to, which is no help at all to anybody.
And asprin may well be an acid, but you still get gastric bleeding if you give it by suppository, so being an acid alone doesn't explain why it causes stomach problems.
So deciding whether you should take LDA depends on your personal risk factor for problems that aspirin has been proven to have a positive impact on. You really need to know what the latest guess of this number is once you hit 40.