An introduction to heartburn and stress
Hydrochloric acid is the main constituent of stomach acid and is an essential component for digestion. Some specific roles of hydrochloric acid include:
- The breakdown of protein
- The effective absorption of vitamins and minerals from your food including vitamin B12, iron, calcium and magnesium
- Keeping bad bacteria under control throughout the digestive tract
- Initiating the release of digestive enzymes further along the digestive system.
Your stomach acid is a strong acid with a pH in the region of between 1 and 3. In order to protect itself, the lining of your stomach has a protective mucous layer which acts as a barrier against the strongly acidic environment.
However, your oesophagus isn’t so fortunate; so, if acid travels backwards, through the lower oesophageal sphincter (LOS) – the circular muscle joining the oesophagus and the stomach – and makes contact with the oesophagus, you feel it. Literally! This is known as acid reflux and the burning sensation under your ribs we associate with this is called heartburn.
But you may be surprised to know that stress can make this pattern of events more likely, why?
What happens to your digestive system when you are stressed?
So, heartburn can be made worse or even be brought on by stress, as many people can vouch for, but, what are the mechanisms behind this?
Firstly, you should consider your nervous system. Your autonomic nervous system contains two branches: the sympathetic and parasympathetic systems. The parasympathetic division is nicknamed the ‘rest and digest’ system. As the name suggests, during this phase you are relaxed, at rest and functions including the digestive, immune and reproductive systems are top priority and are happily working away.
However, in times of stress you shift into ‘fight or flight’ mode as the sympathetic system takes over. This has the opposite effect: stress hormones such as cortisol flood your system and the attention switches from your digestive system (it is effectively switched off) and instead the focus turns to the functions of the heart, lungs and skeletal muscles. This is necessary to prepare us for fleeing from that imposing danger! This was what stress traditionally involved anyway, although, now you are generally faced with fewer life-threatening situations – that ever-growing mountain of paperwork on your desk at work isn’t going to pounce on you anytime soon but your body still reacts in the same way.
This all means that during times of stress, your digestive functions are less controlled. As a result of this the contractions of the muscles of the gut can contract more or less frequently. This can result in diarrhoea or constipation respectively if the muscles within the gut wall are affected, or heartburn if the LOS is malfunctioning. The internal pressure in your stomach can also change which can affect the opening and closing of the LOS too and your gastric secretions can also be altered – including your stomach acid.
There is some debate as to whether stress increases or decreases levels of stomach acid but it is likely it can do both depending on different circumstances (e.g. acute vs. chronic stress). Prolonged stress over time is more likely to decrease your levels of stomach acid.
The gut-brain connection may also have an influence
Your gut and brain are closely linked; the gut has its very own nervous system (the enteric nervous system) which allows for very effective communication.
If you are having toilet troubles it can often make you feel anxious or stressed and when you are stressed you can find yourself visiting the loo a lot more frequently.
As well as suffering from looser bowels during stressful times (as your gut contractions become more erratic), many of you will also be aware of the phenomenon known as ‘butterflies’ which highlights the impact emotions such as feeling nervous or in being in love can have on your stomach.
These are some examples which highlight when the connection between the brain and the gut is particularly apparent. However, in many cases, as you get caught up in a vicious cycle of psychological and physical issues, the link isn’t so obvious.
So is it physical, mental or functions of both that are the cause?
How exactly stress brings about heartburn isn’t well understood and may differ between people. So, there are plausible physical explanations such as increased or decreased acid, both of which can affect the functioning of the LOS. But, as well as this, there may be some mental factors linked to the brain-gut connection theory.
During periods of stress your perceptions and response to pain can also change. This phenomenon is also thought to have a part to play in IBS, as it suggests certain groups of people, under certain circumstances, can have a heightened response to pain. This means you have a more pronounced reaction to pain in comparison to someone who isn’t so stressed.
Interestingly, in addition to this, the type of stress you are under is important. When your stress coincides with stimulating emotions (such as fear) you are less likely to feel pain. This is often reported in people who suffer severe injuries. However, when your stress happens together with more subdued emotions relating to stress, such as anxiety, you are thought to have a heightened response to pain. This theory could also have a part to play.
How else can stress give rise to heartburn?
Stress can have an impact on many aspects of your life. Consider the following scenarios and how they might be influenced by stress.
- Eating habits. When you feel stressed or your mood is low, you are more likely to make poor food choices. Greasy foods high in fat can slow gastric emptying. This means the food you eat will sit in your stomach longer, stimulating the prolonged release of stomach acid that can trigger indigestion and heartburn
- A lack of sleep. Sleep is important for many aspects of your health and is crucial for restoration and repair; both physical and mental. A lack of sleep is thought to affect stomach acid production and the functions of the LOS which together can have you doubled over in pain as they give rise to heartburn
- Posture. When you feel a bit down or under pressure your posture may be affected; you are at risk of hunching over or even curling up on the sofa or in bed – this can affect your stomach. When you fail to sit up straight your stomach becomes squashed which can affect secretions and the function of your sphincters. Walk or sit up tall and let your juices flow and muscles contract in your tummy as they should!
How can you take control?
If you think stress could be contributing to your heartburn, taking control and better managing your stress is likely to be a useful first step in tackling your issues.
Our advice is: don’t suffer in silence. It is important to actively try and manage your stress levels, especially if you think it may be having effects on other areas of your body. Your stomach and digestive system are important and have a huge impact on your overall wellbeing so you need to support them.