Antioxidants and other polyphenols present in coffee confer healthy benefits to the body, which may include lowering insulin resistance, inflammation and biomarkers of liver function.
Coffee is one of the most popular beverages in the world and it is therefore important to understand its effect on our health. Coffee contains caffeine, which is a stimulant, and excessive consumption may not be viewed as a healthy choice. Cohort studies have shown that people who consume coffee have a lower risk of total and cause-speciﬁc death. However, these studies included mainly white participants, and their results may not be duplicated in other populations with different lifestyles, confounding factors, and disease susceptibilities.
In the Multiethnic Cohort (MEC) study, 185,855 participants ages 45 to 75 years were enrolled and followed for an average of 16 years. Participants filled validated food-frequency questionnaires, which were used to determine their baseline coffee intake. After taking into account other causes of mortality like smoking, coffee consumption (both caffeinated and decaffeinated) showed a lower mortality rate compared with those who consumed no coffee at all (1 cup per day: hazard ratio [HR], 0.88 [95% CI, 0.85 to 0.91]; 2 to 3 cups per day: HR, 0.82 [CI, 0.79 to 0.86]; ≥4 cups per day:HR,0.82[CI,0.78 to 0.87]; P for trend <0.001).
Among African Americans, Japanese Americans, Latinos, and whites, consumption of coffee lead to a significant reduction in mortality rate while in Native Hawaiians the reduction in mortality rate was not significant. A reduction in mortality rate was also observed among nonsmokers, participants who were under 55 years old and healthy participants who were not suffering from any form of chronic illness. Deaths that occurred as a result of heart disease, cancer, respiratory disease, stroke, diabetes, and kidney disease were not directly related to coffee consumption. This study had limitations of undetermined effects of confounding factors and measurement errors, but they were unlikely to affect the results.
In the European Prospective Investigation into Cancer and Nutrition (EPIC), 521,330 participants were recruited in the study and followed for 16.4 years. Statistical measurements used included hazard ratios (HRs) and 95% Confidence interval. Of the total deaths that occurred among the participants during the study, those who consumed coffee the most displayed a significantly lower all-cause mortality compared to those who consumed less or no coffee at all (men: HR, 0.88 (95% CI, 0.82 to 0.95); Ptrend < 0.001(men: HR, 0.88 [95% CI, 0.82 to 0.95]; P for trend < 0.001; women: HR, 0.93 [CI, 0.87 to 0.98]; P for trend = 0.009) (men: HR, 0.88 [95% CI, 0.82 to 0.95]; P for trend < 0.001; women: HR, 0.93 [CI, 0.87 to 0.98]; P for trend = 0.009); women: HR, 0.93 (95% CI, 0.87 to 0.98); Ptrend < 0.009).
There was no direct relationship established between coffee consumption and digestive disease mortality among the participants (men: HR, 0.41 (95% CI, 0.32 to 0.54); Ptrend < 0.001; women: HR, 0.60 (95% CI, 0.46 to 0.78); Ptrend < 0.001). Coffee consumption led to lower cardiovascular disease deaths among women (HR, 0.78 (95% CI, 0.68 to 0.90); Ptrend < 0.001) and lower stroke-related mortality among women (HR, 0.70 (95% CI, 0.55 to 0.90); Ptrend < 0.002). However, coffee consumption was shown to have a direct proportional relationship with ovarian related all-cause mortality among women (HR, 1.31, (95% CI, 1.07 to 1.61); Ptrend < 0.015). The limitation of this study was the fact that coffee consumption was assessed only once during the study period.
In conclusion, consumption of coffee was associated with lower risk for death in African Americans, Japanese Americans, Latinos, whites and Europeans.
- 3 to 5 cups of coffee per day can be part of a healthy diet.
- Coffee consumption lowers the rate of death, especially for people with diseases of the digestive tract and circulatory diseases.
- Coffee has antioxidant properties, and its consumption has benefits of reduced insulin resistance, inflammation, and biomarkers of liver function.
Park SY. Freedman ND. Haiman CA. Le Marchand L. Wilkens LR. Setiawan VW. Association of Coffee Consumption with Total and Cause-Speciﬁc Mortality Among Nonwhite Populations. Annals.org on 11 July 2017.doi:10.7326/M16-247
Gunter MJ, Murphy N, Cross AJ, Dossus L, Dartois L, Fagherazzi G, et al. Coffee Drinking and Mortality in 10 European Countries: A Multinational Cohort Study. Ann Intern Med. [Epub ahead of print 11 July 2017]: doi: 10.7326/M16-2945
Ding M, Bhupathiraju SN, Satija A, van Dam RM, Hu FB. Long-Term Coffee Consumption and Risk of Cardiovascular Disease: A Systematic Review and a Dose-Response Meta-Analysis of Prospective Cohort Studies. Circulation. 2014;129(6):643-659. doi:10.1161/CIRCULATIONAHA.113.005925.
Josephat Macharia, PharmD candidate, Lecom School of Pharmacy class of 2018