A recent study has investigated whether how coffee is made affects its protective effect against type 2 diabetes.
Research has identified that drinking coffee is associated with a reduction in the risk of type 2 diabetes, however, does the method of brewing have any impact on this protective effect? That’s what researchers from Sweden wanted to find out.
The researchers studied two different methods of coffee brewing; filtered and boiled. Filtered coffee is the process of passing water over ground coffee that is placed in a filter, a common method in North America. Whereas boiled coffee is a method where a coarse grind of coffee is added directly to boiled water, this method is more typically seen in the UK.
To be able to tell the difference between the effects of filtered versus boiled coffee, the researchers used a method by which they measured specific molecules in the blood of participants – ‘plasma metabolites’.
Specific types of metabolites within the plasma of participants were associated with either drinking boiled coffee or filtered coffee. The researchers reported an inverse association between the types of metabolites measured in participants who drank filtered coffee and risk of type 2 diabetes. That is, the higher the amount of metabolites, the greater the reduction of risk. This protective effect was seen in people who drank 2-3 cups of filtered coffee per day. The researchers reported a 60% reduced risk of going on to develop type 2 diabetes in this group. This association was not seen in the group of participants who had consumed boiled coffee.
The researchers concluded that the study “supports a protective role of habitual intake of filtered coffee on T2D development.”
However, they do note that there was a lower number of participants who consumed boiled coffee, stating: “The lack of association for boiled coffee intake might be due to the lack of a protective effect of boiled coffee or due to the limited number of boiled coffee consumers in this population, but it warrants further investigation.”
According to the researchers, more study is needed, investigating not only filtered and boiled, but other brewing methods. There are also other factors that could impact on the health benefits of coffee, not just how it is brewed.
Written by Deborah Tallarigo, PhD
Shi C. Brunius I. Johansson I.A. Bergdahl O. Rolandsson B. van Guelpen A. Winkvist K. Hanhineva R. Landberg (2019). “Plasma metabolite biomarkers of boiled and filtered coffeeintake and their association with type 2 diabetes risk” Journal of Internal Medicine. First published: 09 December 2019 https://doi.org/10.1111/joim.13009
News release: https://www.eurekalert.org/pub_releases/2019-12/cuot-fch121719.php
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