Scientists have found an association between coffee consumption and increased blood sugar levels – according to a study, people with type 2 diabetes who took 500 mg of caffeine daily (the equivalent of two cups of coffee or strong tea) had higher sugar levels.
These studies directly contradict the popular belief that coffee consumption is associated with a lower risk of developing diabetes. This is probably due to the fact that the body of different people reacts differently to drinking coffee.
Can Diabetics Drink Coffee?
Traditionally, coffee drinkers were thought to have a lower risk of developing diabetes, but the results were based on statistical analysis rather than direct experimentation. It is likely that there were secondary factors.
Newer studies have been designed to examine the direct effects of caffeine on the body. In particular, they found that the substance reduces insulin sensitivity – which, as a result, impairs the body’s ability to utilize glucose and is expressed in an increase in blood sugar levels.
However, this conclusion is also ambiguous. A 2018 study determined that sensitivity to the effects of caffeine is determined by the work of at least two genes – and some people’s bodies are able to better (and faster) use caffeine.
Doses studied
The main problem is the varying amount of caffeine in drinks. It is impossible to predict exactly how much is contained in a cup of coffee or tea – it depends on the variety, as well as on the mechanics of brewing.
The dose shown to increase blood sugar levels was 500mg of caffeine (in its purest form) – which could be as much as two cups of espresso or a liter of watery coffee.
The Effect of Caffeine
The mechanism of action of caffeine is based on the blocking of the hormone adenosine and the enzyme phosphodiesterase. By acting on the brain, adenosine leads to relaxation – however, when drinking tea or coffee, this action is blocked, indirectly causing an invigorating effect.
In addition, caffeine increases the level of adrenaline – this hormone can reduce the ability of body cells to use glucose, and can also affect the production of insulin (lowering it). However, much depends on the dose and the level of tolerance of the body.
Natural Antioxidants
The composition of natural coffee includes up to several hundred different components – primarily polyphenols and antioxidants.
Natural tea (especially green tea) also contains powerful natural antioxidants, kakhetins, which can affect metabolism.
However, coffee studies implied the study of the effect of caffeine in its pure form – for more accurate data.
Practical Recommendations
Importantly, the aforementioned study showed that people with type 2 diabetes after drinking coffee changed their body’s response to eating other carbohydrate foods – in particular, blood sugar levels increased more and insulin production changed.
Plus, a 2017 study showed that a cup of caffeinated coffee (versus decaffeinated coffee) affected people’s taste buds—especially their interpretation of food’s sweetness levels, thus increasing sugar cravings.
It is likely that a similar effect can occur with the use of sweeteners. Theoretically, some of them can provoke changes in the processes of insulin production – since the body still tastes sweet.
Outcome
In the explanatory note, the scientists hypothesize that people with diabetes or prediabetes should be extremely careful about the use of caffeine found in tea and coffee – although they add that the studies were conducted on a small number of people (14 subjects).
The effect of caffeine can be especially strong when consumed together with sources of sweet taste – meaning both fast carbohydrates and, possibly, sweeteners.
Based on research data, there is a possibility that drinking coffee may alter insulin production and raise blood sugar levels in diabetic patients – at least in people with a certain combination of genes and increased sensitivity to caffeine.