Why Coffee Protects Against Type II Diabetes

Researchers have known for years that drinking coffee reduces the risk of type II diabetes as we noted in our article, More Organic Coffee Can Lead to Less Diabetes. Now researchers have identified a specific bioactive substance in coffee that stimulates insulin secretion and sugar uptake by muscle cells. The report is in the Journal of Natural Products.

Cafestol, a Bioactive Substance in Coffee, Stimulates Insulin Secretion and Increases Glucose Uptake in Muscle Cells: Studies in Vitro

Diet and exercise intervention can delay or prevent development of type-2-diabetes (T2D), and high habitual coffee consumption is associated with reduced risk of developing T2D. This study aimed to test whether selected bioactive substances in coffee acutely and/or chronically increase insulin secretion from β-cells and improve insulin sensitivity in skeletal muscle cells. Insulin secretion from INS-1E rat insulinoma cells was measured after acute (1-h) and long-term (72-h) incubation with bioactive substances from coffee.

Coffee, Coffea arabica Benth. (Rubiaceae) and Coffea canephora Benth. (Rubiaceae), contains a diversity of bioactive components that varies with coffee species and the roasting and brewing methods.(8-10) The large number of substances includes methylxanthines (especially caffeine), diterpenes (like cafestol and kahweol), the lignan secoisolaricresenol, phenolic acids (e.g., caffeic-, ferulic-, chlorogenic- and quinic acid), trigonelline, minerals, and degradation products.

The specific substance in coffee that stimulates insulin secretion and subsequent uptake of sugar by muscle cells is cafestol. A related compound, caffeic acid has similar effects.

How Much Cafestol Is in Your Coffee?

Since cafestol can be instrumental in fighting type II diabetes how much of the stuff is in your coffee? According to the researchers roasted Arabica coffee beans contain 0.5% caffeic acid while a cup of coffee contains 35 to 175 mg of caffeic acid. Boiled coffee, Turkish coffee and French press coffee contain 6 to 12 mg of cafestol while filtered coffee contains only 0.2 to 0.6 mg of cafestol. It turns out that the paper filter traps and retains the majority of the cafestol when brewing coffee. In addition lighter roasts have more cafestol then darker roasts according to Science Direct.

The extraction yield of cafestol from roast and ground (R&G) coffee beans was evaluated using brews prepared by four brewing mechanisms (boiled, Turkish, French Press and Mocha Pot). The cafestol content of the R&G coffee and the resulting brews was measured and extraction yield calculated. The R&G coffee had an average cafestol content of 603 mg/100 g R&G coffee with a slight reduction at higher roast intensities. In the brews, preparation method had an impact on cafestol concentration with French, Turkish and boiled preparation methods producing the highest cafestol concentrations. The extraction yield of cafestol was shown to be dependent on the brew mechanism and roasting time, with the lightest roast coffee prepared by French press or boiled preparations having the highest cafestol extraction yield (6.5% and 5.84%) and dark roast Mocha and Turkish preparations had the lowest extraction yields of 2.42% and 2.88% respectively.

So, if you want to avoid getting type II diabetes drink coffee and if you really want to avoid type II diabetes consider the French press method or even the old farm kitchen method of boiling the grounds on the stove and letting them settle before serving.




Leave a Reply