Even more caffeine
Ritchie et al (2007) reports from a French cohort study that caffeine may be neuroprotective in women, but not in men. Over 7000 men and women (65 years or older) were followed over a period of 4 years, and women drinking 3 or more cups of coffee per day showed less cognitive decline than their uncaffeinated peers. Men showed no effect in Ritchie's study. However, Van Gelder et al (2007) found a protective effect for men in their study performed in Italy, Finland, and the Netherlands. This study included 676 subjects (male only) and followed them over 10 years. Ritchie also found that coffee consumption was associated with higher level of education and cigarette smoking, while Van Gelder reports no significant difference between coffee consumers and non-consumers. In California, Johnson-Kozlow et al (2002) (n = 1,528) found that women demonstrated a neuroprotective effect from coffee consumption, but not men. Neither men nor women demonstrated any protective effect from decaffeinated coffee. Martin Jarvis (1993) reported that caffeine's performance enhancing effects were stronger in the elderly.
We looked at caffeine in June; I was surprised to see it crop up in the news again. The thing that jumps out at me about these studies is that the smallest cohort (van Gelder) is the only one demonstrating any protective effect for men. Van Gelder's study also combined results from three different countries. I don't feel like this should make a difference, but there may be dietary or lifestyle differences that are not being controlled. Finally, van Gelder's study included no women, so there is no real basis for comparing gender differences between van Gelder's study and the results found by Ritchie and Johnson-Kozlow. While it's possible that caffeine has a protective effect for men, it looks like women have a lot more to gain from a cuppa.
We looked at caffeine in June; I was surprised to see it crop up in the news again. The thing that jumps out at me about these studies is that the smallest cohort (van Gelder) is the only one demonstrating any protective effect for men. Van Gelder's study also combined results from three different countries. I don't feel like this should make a difference, but there may be dietary or lifestyle differences that are not being controlled. Finally, van Gelder's study included no women, so there is no real basis for comparing gender differences between van Gelder's study and the results found by Ritchie and Johnson-Kozlow. While it's possible that caffeine has a protective effect for men, it looks like women have a lot more to gain from a cuppa.