Three Cups of Coffee A Day can Do More Good Than Bad

Summing up the benefits of coffee from over 200 odd studies, a new study shows that drinking coffee may be associated with more health benefits than doing harm. Moderate coffee consumption, three to four cups a day, lowers risk of heart disease, few types of cancers, diabetes, liver disease and dementia. While the study recommends coffee for most, pregnant women and those at risk for fractures are not recommended caffeine due to safety concerns. The study is published in The BMJ.

Study Overview

The study was a compilation of evidence from over 200 observational studies that discussed the health benefits and problems associated with coffee consumption. The study is also in sync with recent studies that have addressed the benefits of drinking coffee. To capture a larger understanding, a team led by Dr Robin Poole, Specialist Registrar in Public Health at the University of Southampton, and collaborators from the University of Edinburgh, carried out an umbrella review of 201 observational studies and 17 clinical trial data from all across the country. An umbrella review provides a high quality summary on the health benefits of coffee consumption based on previous meta-analyses.

Study Revelations

• Largest risk reduction of all-cause related death was observed in people who consume 3 cups of coffee a day when compared to non-coffee drinkers. However, consuming more than 3 cups made the beneficial effects less profound and added a higher harm ratio.
• Coffee lowers risk of several cancers including prostate, endometrial, skin and liver cancer.
• It also reduced the risk of type 2 diabetes, gallstones, gout.
• The largest risk reduction benefit was for liver conditions such as liver cirrhosis.
• Consumption of coffee was also beneficially associated with Parkinson's disease depression and Alzheimer's disease.
• Coffee consumption is not recommended for pregnant women due to increase in risk of fractures. Likewise, it is also not recommended for people who are prone to fractures.

Limitations of the study

Since most of the data came from observational studies, the causal effect cannot be determined, lowering the quality of the evidence. Also, factors like smoking, lifestyle, food habits, and exercise varied vastly from study to study. The team therefore did not rule out the effect of such factors on the benefits or harm of coffee consumption. The fact that coffee is often consumed with products such as milk, refined sugars and other additives are also not considered while calculating the health benefits. Controlled randomized trials are required to accurately weigh the harms and benefits of coffee consumption.

In a linked editorial, Eliseo Guallar, at the Johns Hopkins Bloomberg School of Public Health said that although we can be reassured that coffee intake is generally safe, doctors should not recommend drinking coffee to prevent disease - and people should not start drinking coffee for health reasons.

Ultimately, the study shows that “moderate” coffee consumption is safe and can be incorporated into the healthy diet of most of the adult population.

References:

1. Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes, The BMJ - (http://www.bmj.com/content/359/bmj.j5024)

Source-Medindia