Caffeine Reduces Cognitive Decline in Women

Susan Jeffrey
August 9, 2007 — Results from a cohort study suggest that caffeine may reduce cognitive decline in women without dementia. French researchers report that women who drank more than 3 cups of coffee per day had less decline during 4 years of follow-up compared with those who drank a cup or less. However, no such effect was seen in men.
The results are published in the August 7 issue of Neurology.
"Caffeine is a psychostimulant which appears to reduce cognitive decline in women," said lead study author Karen Ritchie, PhD, of INSERM, the French National Institute for Health and Medical Research, in Montpellier, France, in a statement from the American Academy of Neurology.
"While we have some ideas as to how this works biologically, we need to have a better understanding of how caffeine affects the brain before we can start promoting caffeine intake as a way to reduce cognitive decline," she noted. "But the results are interesting — caffeine use is already widespread and it has fewer side effects than other treatments for cognitive decline, and it requires a relatively small amount for a beneficial effect."
Reduced Risk With Caffeine
Previous studies have suggested that caffeine, which is known to have positive effects on vigilance, attention, mood, and arousal, may also be neuroprotective, the authors write.
In this study, the researchers used data from the Three City Study, a multisite cohort study of community-dwelling elderly persons in Bordeaux, Dijon, and Montpellier, France, to examine the association between caffeine intake, cognitive decline, and incident dementia, taking into account the potential effects of sex, as well as accounting for any preexisting and current clinical or sociodemographic factors that might contribute to cognitive decline.
Subjects included 4197 women and 2820 men. The researchers assessed cognitive function, any clinical diagnosis of dementia, and caffeine consumption at baseline, and then at 2 and 4 years of follow-up.
They found that caffeine consumption was associated with a wide range of sociodemographic, lifestyle, and clinical variables that might also have an effect on the rate of cognitive decline, such as education level and smoking. Women were higher consumers of caffeine, they note, with 16.4% of women vs 13.2% of men consuming more than 3 units per day.
Multivariate mixed models and multivariate adjusted logistic regression showed that women with high rates of caffeine consumption, more than 3 units per day, had less decline in verbal retrieval and to a lesser extent, visuospatial memory during 4 years, the authors write.
No relation was seen between caffeine intake and cognitive decline among men, they note. "Women may be more sensitive to the effects of caffeine," Dr. Ritchie said in the American Academy of Neurology release. "Their bodies may react differently to the stimulant, or they may metabolize caffeine differently."
However, in these findings at least, there was no effect of caffeine consumption in terms of the development of dementia during 4 years. "Although no impact was observed on dementia incidence, further studies are required to ascertain whether caffeine may nonetheless be of potential use in prolonging the period of mild cognitive impairment in women prior to a diagnosis of dementia," they write.
The Three City Study is conducted under a partnership agreement among INSERM, the Victor Segalen-Bordeaux II University and Sanofi-Synthelabo. The authors have disclosed no relevant financial relationships. Other financial relationships are listed in the original article.
Neurology. 2007;69:536-545.