We’ve been waiting for this discovery for years, patiently sipping away at our cuppa with the hopeful thought that it might one day be of benefit, we’re halfway there. Women who drink four cups of coffee a day are 20 per cent less likely to become depressed than women who rarely drink coffee.
Caffeine is the most frequently used central nervous system stimulant in the world, and approximately 80 percent of consumption is in the form of coffee, according to background information in the article. Previous research, including one prospective study among men, has suggested an association between coffee consumption and depression risk. Because depression is a chronic and recurrent condition that affects twice as many women as men, including approximately one of every five U.S. women during their lifetime, “identification of risk factors for depression among women and the development of new preventive strategies are, therefore, a public health priority,” write the authors. They sought to examine whether, in women, consumption of caffeine or certain caffeinated beverages is associated with the risk of depression.
Michel Lucas, Ph.D., R.D., from the Harvard School of Public Health, Boston, and colleagues studied 50,739 U.S. women who participated in the Nurses’ Health Study. Participants, who had a mean (average) age of 63, had no depression at the start of the study in 1996 and were prospectively followed up with through June 2006. Researchers measured caffeine consumption through questionnaires completed from May 1980 through April 2004, including the frequency that caffeinated and noncaffeinated coffee, nonherbal tea, caffeinated soft drinks (sugared or low-calorie colas), caffeine-free soft drinks (sugared or low-calorie caffeine-free colas or other carbonated beverages) and chocolate were usually consumed in the previous 12 months. The authors defined depression as reporting a new diagnosis of clinical depression and beginning regular use of antidepressants in the previous two years.
Analysis of the cumulative mean consumption included a two-year latency period; for example, data on caffeine consumption from 1980 through 1994 were used to predict episodes of clinical depression from 1996 through 1998; consumption from 1980 through 1998 were used for the 1998 through 2000 follow-up period; and so on. During the 10-year follow-up period from 1996 to 2006, researchers identified 2,607 incident (new-onset) cases of depression. When compared with women who consumed one cup of caffeinated coffee or less per week, those who consumed two to three cups per day had a 15 percent decrease in relative risk for depression, and those consuming four cups or more per day had a 20 percent decrease in relative risk. Compared with women in the lowest (less than 100 milligrams [mg] per day) categories of caffeine consumption, those in the highest category (550 mg per day or more) had a 20 percent decrease in relative risk of depression. No association was found between intake of decaffeinated coffee and depression risk.
“In this large prospective cohort of older women free of clinical depression or severe depressive symptoms at baseline, risk of depression decreased in a dose-dependent manner with increasing consumption of caffeinated coffee,” write the authors. They note that this observational study “cannot prove that caffeine or caffeinated coffee reduces the risk of depression but only suggests the possibility of such a protective effect.” The authors call for further investigations to confirm their results and to determine whether usual caffeinated coffee consumption could contribute to prevention or treatment of depression.
source: science daily
Authors: 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
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.
Author Affiliations: Departments of Nutrition (Drs Lucas, Mirzaei, Pan, Willett, O’Reilly, and Ascherio) and Epidemiology and Harvard School of Public Health, Channing Laboratory (Drs Okereke, Willett, and Ascherio), and Departments of Medicine and Psychiatry (Dr Okereke), Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts; and Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, New York (Dr Koenen).