Two studies: Coffee Consuimption and Prostate Cancer Prevention

Coffee associated with lower risk of death
A study just published in the Annals of Internal Medicine called The Relationship of Coffee Consumption with Mortality looked at 41 736 men and 86 214 women from the Health Professionals Follow-up Study and Nurses' Health Study. They found that men and women who regularly drank a few cups of coffee each day were slightly less likely to die then those that did not drink coffee regularly, mainly due to fewer deaths from cardiovascular disease.

So, should you drink coffee to prevent death?
Not necessarily. These type of studies are called cohort studies, where a group is examined for a period of time to try and ascertain whether or not something is associated with a disease. However, association and cause is not necessarily the same thing. For example, people who attend NASCAR events (sorry racing fans) are more likely to smoke. However, just by attending a NASCAR event doesn't cause you to smoke. There are clearly other factors involved. The researchers tried to control for these factors by taking into account many factors that may have played a role in association between life expectancy and coffee including: smoking status, body mass index, physical activity, alcohol intake, use of hormone therapy for women, parental history of myocardial infarction, and dietary factors. Given this, the results should be considered. However, the only way to prove that drinking coffee will prolong your life would be to do a study with non-coffee drinkers and randomize them into two groups: those that would start drinking coffee and those that continued not to drink coffee.

Bottom Line: At a minimum, the study suggests that there is no inherent risk of drinking coffee. If you drink coffee you probably don't need to stop. However, if you don't drink coffee, there is really no compelling reason to start. For coffee drinkers, also remember that though coffee doesn't have any calories, the other things you put into that coffee do, and these calories can increase your risk for weight gain, diabetes, and possibly death.

Prostate Cancer Prevention.
The New York Times did an excellent job explaining some interesting new findings recently published on some old data from an old but controversial study. This well done study showed that finasteride, a now generic medication used for shrinking men's prostate to relieve the symptoms (BPH) was also associated with about a 25% risk in new prostate cancer. Given that prostate cancer is the 3rd leading cause of cancer death in men, why did physicians not start giving all men finasteride back in 2003, when the study was published? Because of the finding that the more of the tumors that did occur in men taking finasteride were a higher grade, and thus theoretically more dangerous. One of the controversies with prostate cancer is that of the many men who have prostate cancer, most will die of something else. The evidence that screening for and then treating prostate cancer in order to save peoples lives is controversial, and not all physician groups even recommend that men get an annual exam and PSA test.
Thus, from the NY times:
"The concern was that the drug might be preventing cancers that never spread. At the same time, finasteride might actually be causing aggressive cancers that can kill."
However, the conclusions in the 2003 paper were based on prostate biopsies, which only look at tiny pieces of the prostate. Most of the men where prostate cancer was found had their prostates removed, and so the researchers over that last several years have painstakingly looked at all of these prostates and found that taking finasteride reduced the risk of having any tumor, aggressive or non-aggressive.

Bottom line: This is very compelling evidence that suggests men should take finasteride to prevent prostate cancer. The medicine is now also generic, so cost is not an major issue. In addition, many men do develop symptomatic BPH, which the drug can also treat. There are side effects, including sexual dysfunction, so this should be taken into account.