Coffee ceramic mug - How Does Caffeine Impact Your Gut?

How Does Caffeine Impact Your Gut?

Coffee ceramic mug 1 300x200 - How Does Caffeine Impact Your Gut?

Many adults can’t imagine starting their days without a hot cup of coffee. According to a survey by Statista, Canadians drink three cups of coffee per day on average.


The caffeine in coffee helps people feel energized as it increases alertness and elevate mood as caffeine raises dopamine, a neurotransmitter that increases alertness, focus and attention, as well as, positive feelings/mood.


It is for this reason that coffee consumption is associated with lower rates of depression; however, people drink coffee not just to wake them up or give themselves an energy boost. In fact, many drink coffee when they need to take a break and relax.


Coffee is their companion when they need something to pass the time or when they need to focus.


Coffee love

The love for coffee is undeniable, and its benefits are widely known too.


Coffee has been shown to reduce the risk for cognitive decline, reduce the risk for liver cancer and diabetes. However, because caffeine is acidic, it slightly increases the amount of gastric secretions in your body, which may result in the irritation of the stomach and intestinal lining.


This can ultimately lead to an upset “stomach”. Fortunately, this only tends to affect a small number of people when coffee is drunk on an empty stomach; consuming coffee with some food reduces this effect.


And if you have irritable bowel syndrome, Crohn’s disease, or other gastrointestinal problems, caffeine can worsen the symptoms. This is because certain enzymes found in coffee trigger immune responses that may lead to bloating, inflammation, cramping, diarrhea, and gas.


Coffee cups five 1 300x200 - How Does Caffeine Impact Your Gut?


As well, caffeine is also a gastrointestinal stimulant. It can get things moving when it comes to pooping;  a study found that 29% of participants needed to use the bathroom within twenty minutes of drinking a cup of coffee (1).


The caffeine in coffee stimulates contractions of the colon (large bowel) and the intestinal muscles (2, 3). While caffeinated coffee has more of an effect than decaf, decaf can also make you poop (4). Coffee, both regular and decaf, stimulate the release of a hormone called gastrin which also makes the colon more active (5).


Like anything, there’s a lot of variation between people and their ability to tolerate foods.


This effect doesn’t affect everyone though and regular coffee drinkers tend to notice less of an impact than occasional consumers of caffeine; not surprisingly tolerance plays a role but regardless, those with gastrointestinal health issues need to factor how coffee, tea, caffeine etc. impacts their quality of life and disease management.


So just say no?

Before you panic and rid your pantry of all your coffee supply, know that these symptoms are most common in people who suffer from existing gastrointestinal problems. In otherwise healthy adults, coffee is fine as long as you stay within the recommended amounts.


Health Canada recommends limiting caffeine consumption to about 400 mg per day or the equivalent of three to four, 250 ml (8 oz) coffees per day.


Note that most coffee franchises no longer serve 8 oz servings, Starbucks and Tim Horton’s come to mind as exceptions, both have smaller servings that are about 8 oz but they never offer it, you have to ask for a ‘short’ at Starbucks and an ‘extra small’ at Tim’s; they’ll start with offering you a large cup right off the bat; bigger cups = more caffeine over the course of the day.


Essentially all other coffee houses default to larger serving sizes too; a ‘small’ coffee which is 12 oz, a medium at 16 oz and large at 20 oz which translates to about 188 mg, 250 mg, and 312 mg of caffeine per cup respectively so when a client tells me they have 3 cups of coffee per day, I always have to quantify this as much as possible.


Bottom line

In short, as a country we are becoming increasingly caffeinated all day long, but as mentioned, no need to panic. Take stock and cut back as needed. Too much caffeine does stay in our system and studies show it can interfere with getting good quality sleep.


If you’re drinking several cups per day, especially with some in the afternoon, you’ll be going to bed with caffeine in your system. Studies show that this can interfere with sleep quality; yes, you’ll still fall asleep but you won’t necessarily be getting the best sleep possible.



According to Medical News Today, regular coffee drinking comes with many health benefits when consumed responsibly including the protection against type 2 diabetes, liver disease, liver cancer, and Parkinson’s disease and dementia.


Coffee even promotes a healthy heart. Coffee is also a rich source of antioxidants with both caffeinated and decaffeinated versions containing almost the same levels of antioxidants.


Doug Cook RDN is a Toronto based integrative and functional nutritionist and dietitian with a focus on digestive, gut, mental health.  Follow me on FacebookInstagram and Twitter.

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