Whether yours is a short black or a flat white, here’s how your coffee order can impact your belly and digestion, from greater “regularity” to buzz-induced bloating

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I recently interviewed a number of women suffering from IBS , and all of them identified coffee as a trigger for their digestive symptoms and tummy discomfort. Many had found it difficult to give up, but the after-effects of an americano simply weren’t worth the hot lift that a cup of java provides.

As a non IBS-sufferer yet coffee fiend, it got me to wondering (apologies for the Carrie Bradshaw-ism) whether my usual morning filter might be having an effect on my gut. I consider coffee a pretty indispensable colleague in my rounds of daily deadlines, and have definitely noticed that it doesn’t simply speed along my word count (ahem). I put my coffee quandaries to Registered Nutritionist Daniel O'Shaughnessy  for a little clarification on the bean vs. belly topic. We’ll start with the most pressing issue...

Does coffee make you need the loo?

In a word: affirmative:

“The caffeine in coffee can activate contractions in your colon and intestinal muscles and therefore make you need to go to the bathroom. It may not just be the caffeine that’s having this effect either- it’s possible that chlorogenic acids and N-alkanoyl-5-hydroxytryptamide (a chemical closely related to the neurotransmitter serotonin) in coffee could play a role in those more frequent loo trips due to the fact that they stimulate stomach acid, moving food through the digestive tract at a quicker rate as a result.”

If you’re sprinting to the ladies within a matter of minutes, it’s not necessarily the case that you’ve metabolised coffee at lightning speed- a cup of joe can get your pipes going within five minutes thanks (or no thanks) to its chemistry:

“Coffee can also stimulate hormones that help to push food through the gut. In particular it can increase levels of gastrin which makes the colon more active.”

Getting things moving isn’t in itself a bad thing, of course, particularly if you’re bowels are on the slow side, but you can have too much of a good thing. There’s no recommended daily intake of coffee itself, but it’s generally advised that you cap caffeine uptake at 400mg (between three to five cups) a day, or 200mg if you’re pregnant. This is just a ballpark figure, as many of us react very differently to caffeine, with some people more sensitive to a double shot than others.

Why do some of us experience adverse espresso effects?

The precise reason why some us consider coffee as our lifeblood, while others experience bloating , gurgling and all manner of digestive symptoms after a few sips, isn’t yet known, but how we can tolerate coffee is thought to be down to everything from genetics to our metabolism and unique microbiome . As coffee is acidic, and stimulates stomach acid, it can act as an irritant, particularly if you suffer from conditions such as  IBS , and thus can provoke swelling, bloating and sudden diarrhoea if you have a delicate digestive system. Coffee drinking has also been linked to heartburn, as coffee can induce acid reflux, so if you regularly reach for the Rennies it may be a good idea to monitor your macchiato intake.

If you experience coffee jitters, palpitations and anxiety , these caffeinated aftershocks could also be causing your gut upset, as Daniel explains:

“Caffeine can release the stress hormones cortisol, adrenaline and noradrenaline. As a result, it may cause your body to revert to an ‘emergency state’, whereby blood is diverted away from the digestive system, which can cause indigestion. If this sounds familiar, you don’t have to give up coffee altogether, but consuming it when you’re not in a stressful state should prevent any bellyache. Often we think that drinking coffee will help us to get through a stressful situation, but for a fair few of us the opposite is true. We all have genetic variants that impact our coffee metabolism and stress hormone breakdown. There is always that person who drinks one cup of coffee and experiences severe anxiety, so if this is you, be mindful of your triggers and switch to a gentler alternative.”

Just don’t switch too suddenly- as caffeine is a stimulant, it causes a physical dependence (albeit a mild one), so you may experience withdrawal symptoms such as headaches, fatigue, low mood or other physical symptoms if you slash your cups from five to none. Consider weaning yourself off the coffee cup by cup, and replace your usual grande order with builder’s or green tea for a lighter caffeine hit.

Does how I take it make a difference?

Most of us are aware that a creamy frappadappaccino and simple black coffee carry very different nutritional profiles, but if you’re experiencing less than welcome belly backlash from your latte, the coffee itself may not be the culprit:

“It’s really important to consider whether what you’re having with your coffee is causing the issues. Sugar, artificial sweeteners or cream are common additives, and of course if you’re dairy sensitive, that will cause bloating at best and diarrhoea at worst.”

Most coffee shops offer dairy-free options  these days, and Daniel recommends choosing organic coffee where possible to limit your chances of encountering mould (...apparently a thing in low quality coffee sources).

The timing of your brew could also affect how well it goes down. Coffee alone does not constitute a balanced meal, despite what Instagram memes might have you believe, and a strong black downed first thing on an empty stomach could irritate your gut. Daniel counsels against using your coffee machine as a mental alarm clock:

“Try drinking coffee only with meals, and consume when you only really need it. Get into the habit of waking yourself up naturally rather than hitting the Nespresso machine first thing.”

Easier said than done, but the good news is that drinking coffee after a meal, in the manner of a sophisticated Parisian, could prove beneficial for your gut, as the stimulation of stomach acid can aid digestion.

Are there other gut related perks to coffee?

Aside from speedy “ejections”, not per se:

“Coffee may help in the reduction of risk of gallstones and gallbladder disease, and it’s been proven to beneficial to liver health, but otherwise it’s not directly associated with improving digestion.”

So if I go decaf, any stomach issues will sort themselves out?

You’d think, but…

“Firstly, always choose a water-processed decaf coffee, but studies show that decaffeinated coffee has a similar stimulant effect on the digestion to normal coffee, proving that the laxative effect is not only down to caffeine.”

Curiouser and curiouser. Given that we’re drinking more coffee than ever (95 million cups a day as a nation according to the Centre for Economics and Business Research), we won’t be casting away the cafetières any time soon, and there’s no need to either- scientists propose that the high levels of antioxidants present in coffee can have a protective effect on cells, and that regular consumption bestows more health benefits than drawbacks, although more rigorous research is required. In the meantime, here’s how to have healthy relationship with caffeine  while still relishing a ristretto. Just hold the sugar syrup and whipped cream.

Would you put butter in your coffee?

Follow Daniel on Twitter  @NkdNutrition  ‏and Anna on Instagram  @annyhunter