A recent analysis of the much-lauded Nurses Health Study (which followed over 80,000 US women for nearly 25 years to document their lifestyles and health conditions) found a preliminary correlation between coffee consumption and a reduced risk of stroke.
Performed by members of the Harvard Medical School and Harvard School of Public Health, the analytical study found that women who lived a healthy lifestyle (particularly, non-smokers) and drank 4 or more cups of coffee each day had a 20% lower risk of stroke. Since it tracked the intake of several types of beverages that contained caffeine such as tea and sodas, the study was able to focus in on the effect of drinking coffee itself, meaning that the benefit is likely not sourced in caffeine but another molecular attribute unique to coffee.
Since the study is just out and will no doubt go through further analysis, it opens up an interesting discussion around diet and behavior — namely, do women who drink coffee at this level share anything else in common, specifically in regard to physical activity? The study authors are careful to note that this is just the first stage of analysis and that further research will be done in an attempt to determine the exact source of the benefit.