Coffee is a surprisingly hot topic. For some, coffee is the elixir of life, giving them the power they need for the day, along with claims that it protects against various ailments. For others, coffee is a suspicious psychoactive drug that comes with claims that it is bad for the heart and cholesterol levels.
Considering this controversial topic, the matter of coffee and diabetes is equally open to question. Indeed, how does coffee affect blood sugar? Is coffee as holy or evil as people claim? Or is the answer a more nuanced one that focuses on the balance that comes with a balanced blood sugar? (We’ll go with the latter.)
Let’s bust some myths and get to the bottom of coffee and diabetes!
Coffee: the General Facts
Instead of arguing the different sides of the great coffee debate-off, we can have a look at the straight facts.
Caffeine is the component in coffee that causes reactions in the body. It is a stimulant which triggers chemical reactions to affect different areas of the body. The oils in coffee (diterpenes) and other components that come with caffeine (such as chlorogenic acid) may also affect the body:
The brain is stimulated which makes a person feel more alert.
The heart rate is raised as caffeine causes the heart to beat faster.
Blood vessels become narrowed, leading to a momentary rise in blood pressure.
Headaches may occur, particularly as a reaction to the narrowing and subsequent re-widening of the blood vessels around the brain.
Caffeine is mildly diuretic, which means that a coffee drinker might need to urinate more often.
Caffeine stimulates the bowels, leading to more bowel movements. It is mainly chlorogenic acid in coffee which is responsible for this stimulation. So, even decaffeinated coffee – which retains chlorogenic acid – will make you want to go for a number 2.
As with any stimulant, the body may gain a dependency on caffeine: a coffee addiction is possible.
Coffee oils or diterpenes interfere with the body’s ability to process cholesterol, leading to a rise in cholesterol levels. The extent of these diterpenes depends on how the coffee is made: a paper filter when brewing coffee will be most effective at blotting out those oils. (This is also true for decaf coffee.)
Various studies suggest that coffee can have impacts in other areas, particularly as an anti-inflammatory or as a defense against certain diseases. However, little is solidly known about the causes or direct impact of coffee in these areas. As such, it is difficult to categorically state (yet) that coffee has such beneficial effects.
Otherwise, the question of coffee’s usefulness depends on circumstances. For instance, a person who is tired and needs to be alert will clearly benefit from the stimulation that coffee provides. This is also true for a person who needs to undertake a great deal of physical activity as athletes can even use coffee to enhance performance.
Conversely, a person who needs to sleep will most likely have their rest disrupted by coffee. It may even be the case that a tired person who requires coffee to remain awake is tired precisely because coffee has interfered with their sleep cycle.
This points to one conclusion: balance is everything. Coffee may indeed contribute to a rise in blood pressure and cholesterol. On the other hand, there is little evidence to suggest that one or two cups of coffee a day will impair health. It’s a matter of not going overboard with the coffee.
So, if you’re getting jittery from coffee: it’s probably time to stop drinking it for the day.
(Oh and don’t forget that coffee can give you a bad breath!)
Coffee: the Myths
With so many claims about coffee, we should also consider what isn’t fact:
- “Coffee makes you dehydrated”. Coffee doesn’t automatically dehydrate you. It is, as stated, mildly diuretic, but this is unlikely to have a vast impact on dehydration. Have a glass of water with your coffee just to stay on the safe side.
- “Coffee makes you lose weight”. Studies do suggest that coffee can help with metabolism. This alone, however, is unlikely to have a huge effect on weight loss. The only true method to lose weight is to consume fewer calories than you expend.
- “Coffee protects against diabetes”. While some studies suggest that coffee can lower the risk of certain conditions, one should always be cautious of claims that certain substances will prevent a person from having diabetes. This is especially true for type 1 diabetes, which is an autoimmune condition: coffee would make no difference to an autoimmune condition.
- “Coffee causes cancer.” The World Health Organization says otherwise.
- “Decaf is worse.” Decaf obviously doesn’t have caffeine, but that doesn’t make it worse. Decaf still contains some of the components that caffeinated coffee has (including the one that makes you want to poop.)
Coffee, Blood Sugar, and Balance
Now that we have a better understanding of the effects of coffee, we can see the effects of coffee and diabetes becoming clearer. We can draw four prominent points:
- Sleep. Diabetes and sleep go hand-in-hand. That is to say, the better sleep a person has, the better their body can respond to the needs of diabetes. If coffee disrupts sleep, then insulin sensitivity can decrease.
- Overstimulation. The stimulation that comes with coffee may decrease insulin sensitivity due to the combination of stress and diabetes. To help with increased activity, the levels of stress hormones in the body, such as cortisol, are increased. This leads to a rise in blood sugar.
- Cardiovascular issues. People with diabetes already need to be aware of the cardiovascular system due to the potential damage of blood vessels that might come with high blood sugar. Coffee’s effect on both cholesterol and blood pressure should be considered.
- Dehydration. While coffee doesn’t necessarily cause dehydration, those with diabetes should nonetheless be wary of how often they need to make trips to the bathroom. Losing fluids can lead to a higher concentration of glucose in the blood.
These four points may seem alarming in combination but again: it’s all about balance. Too much coffee is likely to negatively affect diabetes. But a couple of cups? Well, that’s not going to make a tremendous amount of difference.
In fact, one study suggests that habitual coffee drinkers had increased insulin sensitivity and a decreased risk of type 2 diabetes. Conversely, that same study observed lower insulin sensitivity in the short-term and a higher concentration of glucose (sugar) in the blood.
So, again: how does coffee affect blood sugar? The best way is to record your own body’s responses to coffee. Try Hedia’s diabetes logbook to easily record blood sugar levels after having had coffee to find a pattern. You can even get an overview of blood sugar levels over time with the diabetes dashboard.
Coffee and Diabetes: good or bad?
Ultimately, the answer to this question is up to you. It is certainly possible to live without the combination of coffee and diabetes: a person with diabetes doesn’t need coffee.
But coffee can certainly add energy to life – and if it happens to help with blood sugar control, then great!
If you find that coffee complicates blood sugar levels, then leave it alone (or see if decaf makes a difference).
The only answer that can be definitely given now is: balance is key.