"Cancer is pretty lethal and we're not really good at fixing it yet, so when we find something that can really reduce the risk (and there aren't many - the only other ones I can think of are the magical substances known as not-smoking and avoiding-massive-doses-of-ionizing radiation), we should be all over that like cats on yarn."

Maintaining moderately high blood levels of vitamin D may reduce over all cancer rates by up to 30%. There is also evidence for green tea significantly reducing cancer rates.

Aspirin is an anti-coagulant so wounds take longer to stop bleeding. A surgeon will require that you stop taking aspirin long enough for the blood clotting factors to recover. (Surgeons hate it when they can't stop the bleeding.) If I were under 30 I wouldn't take a daily aspirin as I doubt it provides any benefit and does increase risk slightly. By the time you are 40 your body tissues are in a state of mild, chronic inflammation. That may be good for fighting off infections but isn't so good for the cardiovascular system, lungs, and brain. I recommend baby aspirin for anyone over 40.

Moderate alcohol use is correlated with a significant reduction in cardiovascular events. As with aspirin I would only recommend it for older people and then only if the likelihood of abuse is small.