Drinking 3 to 4 cups of coffee per day linked to potential health benefits
The largest risk reduction was associated with drinking 3 cups of coffee per day.
Coffee consumption appears to be generally safe and is more likely to be beneficial than harmful, with peak benefits associated with drinking 3 to 4 cups per day, according to a study published in the BMJ.
Robin Poole, from the Academic Unit of Primary Care and Population Sciences, University of Southampton in the UK, and colleagues analyzed 201 meta-analyses of observational research with 67 unique health outcomes and 17 meta-analyses of interventional research with 9 unique outcomes. Coffee consumption was measured in various exposures, including high vs low consumption, any vs none, and 1 extra cup a day.
The researchers found that coffee consumption was beneficial for multiple health outcomes, including: type 2 diabetes, oral cancer, cirrhosis, renal stones, Parkinson disease, leukemia, mortality after myocardial infarction, gout, liver cancer, and chronic liver disease.
The highest exposure of coffee consumption (7 cups a day) was linked to a 10% lower risk for all-cause mortality (relative risk, 0.90). However, the largest relative risk reduction was linked to consuming 3 cups a day (0.83).
Coffee was not significantly associated with harmful health outcomes. However, the highest relative risk estimates were in acute childhood leukemia, lung cancer, pregnancy loss, rheumatoid arthritis, low birth weight, lymphoma, laryngeal cancer, first trimester preterm birth, third trimester preterm birth, and oral cleft malformation.
The investigators observed inconsistencies regarding harmful associations of coffee consumption with health outcomes related to pregnancy. Compared with low coffee consumption, high consumption was linked with a higher risk for pregnancy loss (odds ratio, 1.46) and low birth weight (odds ratio, 1.31).
“There is no consistent evidence of harmful associations between coffee consumption and health outcomes, except for those related to pregnancy and for risk of fracture in women,” concluded the researchers.
In an accompanying editorial published in the BMJ, Eliseo Guallar, MD, from the Departments of Epidemiology and Medicine at Johns Hopkins Bloomberg School of Public Health, wrote, “The evidence is so robust and consistent across studies and health outcomes, however, that we can be reassured that drinking coffee is generally safe, although some caveats apply.”