world's most widely used central nervous system stimulant
~80% consumed in the form of coffee
past research has found
no significant effects of caffeine on cardiovascular disease
modest decreases in markers of inflammation
and no or modest protective effects in certain malignant neoplasms
a few cohort studies have found a "strong inverse association" between coffee consumption and suicide.
Finland study ( Eur J Epidemiol. 2000;16:789-791) findings:
risk for suicide decreased progressively for those consuming up to 7 cups of coffee per day
over 8 cups/day the rate begins increasing again
THE NEW STUDY based on data from NURSES HEALTH STUDY
NHS data collection began in 1976, n=121,700 f=women 30-55 at enrollment, update questionaires each 2 yrs
this round: 10-year observational cohort study can only find associations, not prove causality
first major study to look at coffee/depression
n=50,739 older women, mean age, 63 years at baseline, no depression sx in 1996, followups thru June 06
collected info on coffee (incl decaf), tea, soda (caff & decaf), chocolate
definition of depression: self-reported physician-diagnosed depression and antidepressant use
2607 incident cases of depression were found during the 10 years of follow-up
"inverse, age-adjusted, dose-response relationship was observed between caffeinated coffee and depression risk (P for trend = .03)"
adjustment for alcohol intake did not affect results
FIVE CAFFEINE CONSUMPTION CATEGORIES
1) 1 or less cups/week (100 mg/day or less) is baseline value to which all are compared
2) 2-3 cups per day-- >15% decreased risk for depression (0.85 relative risk (RR) for depression (95% confidence interval [CI], 0.75 - 0.95))
3) 4+ cups or more-->20% decreased risk (RR of 0.80 (95% CI, 0.64 - 0.99; P < .001 for both) )
4) top caff consumers = 550 mg/day or more-->RR of 0.80 (95% CI, 0.68 - 0.95; P = .02)
5) not in study: 0.52% of sample drank 6+ cups and were excluded from evaluation
Not sig assoc c depression: Decaf, caff tea, sugared soft drinks, and chocolate
some women use these as main source of caffeine and don't drink coffee: this could change results
study supported by grants from NIH and from the National Alliance for Research on Schizophrenia and Depression
Dr. Lucas received a fellowship from the Fonds de recherche en santé du Québec
September 26, 2011 medscape post
Arch Intern Med. 2011;171:1571-1578. Abstract
Coffee, Caffeine, and Risk of Depression Among Women
Michel Lucas, PhD, RD; Fariba Mirzaei, MD, MPH, ScD; An Pan, PhD; Olivia I. Okereke, MD, SM; Walter C. Willett, MD, DrPH; Éilis J. O’Reilly, ScD; Karestan Koenen, PhD; Alberto Ascherio, MD, DrPH
Arch Intern Med. 2011;171(17):1571-1578. doi:10.1001/archinternmed.2011.393
Background Caffeine is the world's most widely used central nervous system stimulant, with approximately 80% consumed in the form of coffee. However, studies that analyze prospectively the relationship between coffee or caffeine consumption and depression risk are scarce.
Methods A total of 50 739 US women (mean age, 63 years) free of depressive symptoms at baseline (in 1996) were prospectively followed up through June 1, 2006. Consumption of caffeine was measured from validated questionnaires completed from May 1, 1980, through April 1, 2004, and computed as cumulative mean consumption with a 2-year latency period applied. Clinical depression was defined as self-reported physician-diagnosed depression and antidepressant use. Relative risks of clinical depression were estimated using Cox proportional hazards regression models.
Results During 10 years of follow-up (1996-2006), 2607 incident cases of depression were identified. Compared with women consuming 1 or less cup of caffeinated coffee per week, the multivariate relative risk of depression was 0.85 (95% confidence interval, 0.75-0.95) for those consuming 2 to 3 cups per day and 0.80 (0.64-0.99; P for trend <.001) for those consuming 4 cups per day or more. Multivariate relative risk of depression was 0.80 (95% confidence interval, 0.68-0.95; P for trend = .02) for women in the highest (550 mg/d) vs lowest (<100 mg/d) of the 5 caffeine consumption categories. Decaffeinated coffee was not associated with depression risk.
Conclusions In this large longitudinal study, we found that depression risk decreases with increasing caffeinated coffee consumption. Further investigations are needed to confirm this finding and to determine whether usual caffeinated coffee consumption can contribute to depression prevention.