This post is Grassroots, meaning a reader posted it directly. If you see an issue with it, contact an editor.
If you’d like to post a Grassroots post, click here!

November 20, 2019



Over 60 million Americans experience heartburn at least once a month (according to the American College of Gastroenterology). It’s a really common problem.

However, there are a lot of misconceptions about what heartburn is and what causes it. Firstly, heartburn isn’t a ‘problem’ in itself. It’s actually a symptom of acid reflux (note – there are other causes of heartburn, including stomach ulcers, gastroparesis). Therefore, it’s the acid reflux that we need to address.


The second misconception about heartburn is that it’s caused by too much stomach acid, which is actually a myth.

You see, stomach acid is a good thing. It’s needed for digestion and it acts as an antiseptic. It’s only a problem when it gets outside the stomach, which is what happens in the case of acid reflux. In this case, the stomach acid ‘refluxes’ or flows back up out of the stomach into the esophagus.


It’s because of a malfunction in the Lower Esophageal Sphincter (LES), which is a valve-like muscle in between the stomach and the esophagus. It’s not because of too much stomach acid.

The LES opens up for food and drink to enter, as well as when you need to burp or vomit (like an emergency ejection). When this happens, acid from the stomach touches the esophagus, and it burns, because the skin is so delicate.

So, now we know that acid reflux happens because of a malfunction in the LES, let’s look at what causes this malfunction.



Certain foods can either irritate the LES, weaken the LES (causing it to open) or irritate the stomach lining (causing the LES to open).

The main foods that fall under this category are:

  • Spicy foods

  • Citrus fruits

  • Tomatoes

  • Chocolate

  • Alcohol

  • Coffee

  • Fatty foods

  • Smoking (not a food, I know, but still including it here!)

  • Onions

To alleviate symptoms: try and reduce the amount of these foods that you’re eating and see if you notice a difference.


Magnesium helps your muscles to relax. Therefore, it relaxes the sphincter muscle at the bottom of the stomach, so food can get out and flow into your intestines for the next phase of digestion. When you don’t have enough magnesium, this can’t happen, so the food can’t get out the bottom of your stomach. If it can’t get out the bottom, the only way is up!

To alleviate symptoms: Milk of Magnesia or magnesium supplements can help with this. Also, make sure you’re eating magnesium rich foods, like nuts, seeds, legumes, green leafy veg, milk and yogurt.


Anything that puts pressure on the stomach causes it to push up into the diaphragm. When this happens, acid gets trapped, and the LES can’t close, to the acid is pushed up.

Things that put pressure on the stomach are:

  • Pregnancy

  • Obesity

  • Excess vomiting or coughing

  • Pushing too hard during bowel movements

To alleviate symptoms: just be conscious of the things above that can put pressure on the stomach. Some of them you won’t be able to do anything about (e.g. pregnancy!), but being aware of what’s causing the pressure can help to understand it.


When you eat too much food at once, it fills your stomach and puts too much pressure on it. It also slows your digestion down because it stays in your stomach for too long. All of this causes the LES to open to relieve pressure on your stomach.

To alleviate symptoms: try and eat your food slowly and be conscious of portion sizes. It might be better for you to eat little and often, rather than having a few big meals.


As I mentioned, the biggest misconception around heartburn is that it’s caused by too much stomach acid.

However, low stomach acid is normally the cause of heartburn, for 2 reasons:

1. Your stomach needs acid to digest your food. So, if you don’t have enough, then when food enters your stomach, you won’t be able to digest it quickly enough. Therefore, it isn’t passed out into your intestines, but sits in your stomach for longer. This pressure causes the LES to open and reflux to happen.

2. When stomach acid is low, bacteria can overgrow in your stomach or small intestine (as there’s not enough acid to kill them). These bacteria produce gas, which puts pressure on the stomach and can push the LES open.

To alleviate symptoms: you could try supplementing with extra stomach acid. The easiest and cheapest way to do this, which has been a game changer for many of my clients, is with Apple Cider Vinegar. Mix 1 tbsp of it with a small amount of water and drink before each meal.


Heartburn is a really common problem.

There are many misconceptions around it – the truth is that it’s a symptom of acid reflux and it isn’t caused by too much stomach acid.

5 Causes of Heartburn

  1. Eating certain foods

  2. A magnesium deficiency

  3. Pressure on the stomach

  4. Eating too much too quickly

  5. Low stomach acid

5 Ways to Alleviate Symptoms

  1. Reduce the amount of trigger foods you’re eating

  2. Supplement with magnesium

  3. Be conscious of the things that put pressure on the stomach

  4. Eat slowly and be conscious of portion sizes

  5. Try supplementing with Apple Cider Vinegar

Which one do you think might be causing your heartburn?! Let me know in the comments.

Thank you so much for taking the time to read this and letting me be a part of your journey in taking control of your gut, eating well and living your life.

Sophie x

Leave a Thoughtful Comment

Read 0 comments and reply

Top Contributors Latest

Sophie Bibbs  |  Contribution: 1,630