A new study conducted by a team of researchers from Chalmers University of Technology and Umeå University, both located in the Swedish city of Gothenburg, has confirmed the work of previous research that has suggested a link between coffee consumption and a reduction in the risk of developing type 2 diabetes.
Image Credit: Valentyn Volkov/Shutterstock.com
The team was able to expand on the knowledge gained in previous studies, demonstrating that specifically, it is the consumption of filtered coffee, not boiled coffee, that carries these health benefits.
The study, which was published last December in the Journal of Internal Medicine, explains how this specific form of coffee impacts the plasma metabolites, giving rise to its associated health benefits.
Potential health benefits of coffee identified, but the underlying mechanism remains unknown
The latest figures estimate that more than 30 million adults in the US are living with type 2 diabetes, representing fewer than 10% of the population. Also, a further 84.1 million have prediabetes, a condition that if left untreated can turn into type 2 diabetes.
Given that diabetes impacts on such a large number of people, and that it is associated with an increased risk of developing serious health complications, such as those that affect the eyes, heart, and nerves, it is critical to explore possible strategies to prevent this illness, and that will help scientists develop innovative and effective therapies.
The Swedish team aimed to uncover the underlying mechanism in the relationship between coffee consumption and reduced risk of type 2 diabetes. Several recent studies had provided evidence to suggest this relationship, but the biological reasons behind it had remained speculative.
Filter coffee vs boiled coffee
The team used a new analytic technique called metabolomics alongside classic dietary questionnaires to investigate the different levels of risk of developing type 2 diabetes between different types of coffee drinkers. Metabolomics enables researchers to identify and quantify specific molecules related to certain foods or drinks that are present within a blood or urine sample.
This helps provide more accurate measurements of intake, as opposed to solely relying on self-assessment questionnaires, which are limited by their propensity for human error.
Metabolomics can also be used to examine how certain molecules related to food and drink consumption can impact on a person’s metabolism. This allows researchers to conclude how a particular food or drink can affect the risk of disease. Biomarkers of boiled and filtered coffee intake were selected and used to calculate type 2 diabetes risk.
The results demonstrated a clear difference in the risk of developing type 2 diabetes between those who drank filtered coffee and those who drank boiled coffee. Filtered coffee was associated with a lower risk, while boiled coffee had no impact on risk.
Using the biomarkers to make calculations, the analysis found that those who drank two to three cups of filtered coffee daily were 60% less likely to develop type 2 diabetes in comparison to people who drank just one cup, or less, a day.
The health benefits of filter coffee
The popular opinion on coffee is that it only has negative effects on health. Previous research has indeed shown that boiled coffee can make coffee drinkers more vulnerable to heart and vascular diseases. However, it has been determined that this is related to the presence of diterpenes in boiled coffee.
Filter coffee, on the other hand, does not include these molecules as the diterpenes become trapped in the filter. Coffee contains many other molecules that are beneficial to health, such as phenolic compounds and other antioxidants. Even caffeine has been shown to have positive effects when consumed in moderate amounts.
The results of the study highlight how filter coffee, which does not contain diterpenes, can have a positive impact on health, namely on reducing the risk of diabetes.
Next, scientists will need to look into the impact of diterpenes on sugar metabolism, which is suspected to be related to filter coffee’s unique impact on reducing type 2 diabetes risk.
Further to this, researchers plan to study the numerous other kinds of coffee, to establish whether it is only filtered coffee that carries these benefits.
- Carlström, M. and Larsson, S. (2018). Coffee consumption and reduced risk of developing type 2 diabetes: a systematic review with meta-analysis. Nutrition Reviews, 76(6), pp.395-417. https://academic.oup.com/nutritionreviews/article/76/6/395/4954186
- Santos, R. and Lima, D. (2016). Coffee consumption, obesity, and type 2 diabetes: a mini-review. European Journal of Nutrition, 55(4), pp.1345-1358. https://link.springer.com/article/10.1007/s00394-016-1206-0
- Shi, L., Brunius, C., Johansson, I., Bergdahl, I., Rolandsson, O., Guelpen, B., Winkvist, A., Hanhineva, K. and Landberg, R. (2019). Plasma metabolite biomarkers of boiled and filtered coffee intake and their association with type 2 diabetes risk. Journal of Internal Medicine. https://onlinelibrary.wiley.com/doi/abs/10.1111/joim.13009