You know the feeling. Half an hour after a meal, your stomach sits there like a stone. It burns a little, or swells, or tells you it is full long before the plate is empty. No other organ complains in such slow instalments. Indigestion, also known as dyspepsia, troubles about one adult in five worldwide, more women than men.
Occasional indigestion is normal. Week after week, it wears you down. The usual advice is a list of five gentle remedies: ginger, peppermint, chamomile, apple cider vinegar and fennel. All five are below, put to the test.
But the lists skip the most useful question, which is why your stomach is complaining in the first place. The answer often sits on the plate, in the glass beside it, or in the acid your stomach is not making.
Why your stomach complains
Some causes are worth ruling out before any remedy.
The first is a germ. About half the people on Earth carry Helicobacter pylori in their stomachs, most without a single symptom. In others it inflames the lining and causes ulcers, and sometimes stomach cancer.
To prove that the germ could make a healthy stomach ill, the Australian Barry Marshall swallowed it himself. Within three days he had nausea and bad breath, and by day eight his stomach lining was inflamed. Science has rarely had a braver lunch. In 2005 he shared the Nobel Prize for the discovery.
The others are everyday. Anti-inflammatory painkillers like ibuprofen irritate the stomach lining. Alcohol, smoking and coffee all make indigestion more likely, and so do large meals.
Stress works in both directions. Among 1,900 Australians followed for a year, people with more anxiety and low mood at the start were more likely to develop indigestion by the end. And among those who began calm, a troubled gut predicted anxiety later. The gut and the brain talk to each other, and either one can start the argument.
Too little acid, not too much
Indigestion is usually blamed on too much stomach acid. Often the problem is the opposite.
Acid is what does the work, and we have known it for two centuries. In 1822, a gun fired at close range left a fur trader called Alexis St. Martin with a hole into his stomach that never closed. William Beaumont, who looked after him, saw his chance.
He lowered pieces of food on a string through the hole and pulled them out every few hours to see how far they had got. He also drew off St. Martin's stomach juice and digested food with it in cups, which showed that digestion is chemical work done by acid, not just squeezing. St. Martin ran away at one point. Beaumont had him brought back.
Low stomach acid is common, and it gets more common with age. Over 30% of people past 60 make little or no acid, and 40% of women past menopause make none at all when the stomach is empty. Low acid brings its own complaints: reflux, discomfort in the upper belly, and feeling full after a few bites. Those are exactly the symptoms people call indigestion.
Acid is not only a solvent. The stomach releases its main protein-digesting enzyme in an inactive form, and it switches on only when it meets acid. That enzyme, pepsin, was one of the first ever discovered, by Theodor Schwann in 1836, who named it from the Greek word for digestion. When acid runs short, the enzyme stays half asleep, and a meal of meat sits.
Acid is also the gatekeeper. Human stomach acid is far stronger than most animals' and close to that of the scavengers, built to kill the germs that arrive with food. What a Diet That Supports Your Health Looks Like has how that puts us among the meat eaters. With too little acid, more bacteria get through and can overgrow further down, which brings bloating of its own.
The causes include age, long use of acid-blocking pills and the same H. pylori germ. Running short of the minerals the stomach uses to make acid matters too. Among them are chloride, which comes from salt, and zinc. Why "Drink More Water" Is Incomplete Advice has how the stomach makes its acid from the chloride half of salt, one more reason not to fear good, unrefined salt.
This is where a plant-heavy diet comes in. Protein is one of the main switches for stomach acid: a hormone called gastrin is released when protein reaches the stomach. Plant meals carry less protein. Grains and beans also carry phytate, which locks up zinc in the gut. We found no test comparing stomach acid in vegans and meat eaters, so this is our reading of the facts. But both links point the same way.
Acid Reflux: Why It Keeps Coming Back, and What Settles It, linked below, has the clues that point to low acid, and why antacids can make it worse. The longer case is made in . The supplement sold for low acid is betaine HCl with pepsin, such as , and the reflux article has how to approach it safely. Stop at once if it causes a warm or burning feeling, a sign the lining needs to heal first.
Start with the plate
Before you reach for a remedy, look at what you are eating. Plants carry a lot that the human gut does not handle well.
Fibre is the clearest case. By definition, it is the part of plant food that our own enzymes cannot break down. Some of it passes through untouched, and some is fermented by gut bacteria, which make gas as they work.
When 63 people with long-standing constipation were told to stop eating fibre, those who stopped completely went from a bowel movement every three or four days to one a day. Six months later, none of them had bloating. All six who stayed on a high-fibre diet still did. The patients chose which group to be in, so this was not a controlled test, but the difference was hard to miss. Roughage, it turns out, is rough.
Some plant sugars ferment the same way. Onions, garlic, wheat and beans are full of them. When 30 people with irritable bowel ate a diet low in those sugars for three weeks, their overall symptoms were about half as bad as on a typical diet. They had less bloating, pain and wind.
Some plant foods defend themselves more aggressively. Why Your Fruits and Vegetables Deliver Less Than You Think has the raw kidney bean, four or five of which can cause severe vomiting.
Meat is digested mostly in the small intestine. In people whose large bowel had been bypassed, about nine-tenths of the protein in a beef steak was absorbed before it got that far. Meat, fish and eggs carry no fibre at all, so little is left over to ferment further down. Foods That Upset Your Gut: What's Real and What's Personal, linked below, has why bloated stomachs often go quiet on meat alone, and how to bring other foods back one at a time to find the ones that cause trouble.
Keep meals simple
I keep my own meals simple, with one main food, usually meat, rather than a plate of everything at once. My digestion is quieter for it.
That is my experience, not a tested rule. The old "food combining" rules, which say that protein and starch should never share a plate, were tested for weight loss, where they made no difference. We found no test of simple meals for indigestion. But a meal of meat and little else is easy to try, costs nothing, and leaves your stomach one job instead of five.
Keep drinks away from the meal
A big drink with your meal waters down the acid your stomach has just made.
When healthy adults drank one glass of water on an empty stomach, the acid in 10 of 12 of them was diluted within a minute. It came back in about three. A healthy stomach rebuilds its acid quickly. A stomach that is already short of acid pays more for the dilution, at exactly the moment it needs the acid most. The Hidden Power in Every Bite: Why Some Foods Fill You Up gives the same advice for anyone with weak digestion.
So drink your water between meals, and only sip at the table. A good broth is never watered down, and your stomach acid deserves the same respect.
1. Ginger
Ginger has been used for stomach trouble for centuries, and it does something real: it speeds up how fast the stomach empties.
When 11 people with indigestion took ginger capsules or dummy capsules before a bowl of soup, their stomachs emptied faster after the ginger. Their symptoms did not change. The food left faster. The misery left at the usual time.
So ginger moves food along, but in that test it did not make anyone feel better. It is a pleasant, warming spice, and a safe one to try. The verdict is unproven for indigestion.
2. Peppermint
Peppermint oil is more than just a refreshing addition to your toothpaste. It relaxes the smooth muscle of the gut, and that has been tested properly.
When 96 people with indigestion took capsules of peppermint oil with caraway oil for four weeks, 67% were much or very much better, against 21% on dummy capsules. Their pain fell by 40%, against 22%. In irritable bowel, four tests in 392 people found that peppermint oil cut the chance of symptoms carrying on by more than half.
There is a catch. The same relaxing effect works on the valve at the top of the stomach. If your indigestion comes with heartburn, peppermint can make it worse, which is why Acid Reflux, linked below, tells reflux sufferers to skip mint. If your trouble is bloating and cramps rather than burning, capsules made to open past the stomach, such as , take the oil to the gut instead. The verdict is yes, for bloating and cramps without heartburn.
3. Chamomile
Chamomile tea is the gentle one, and it is often recommended when indigestion comes with stress. On its own, it has almost no testing for indigestion.
It does appear in a famous German blend of nine herbs, sold as Iberogast, alongside peppermint, caraway and liquorice. In 315 people with indigestion, eight weeks of the blend did a little better than dummy drops. Then one of the other nine herbs, greater celandine, was linked to rare cases of liver damage, including a death, and in 2018 the maker was made to add warnings.
So the cup of chamomile is pleasant and harmless. The verdict is a nice evening drink, not a treatment.
4. Apple cider vinegar
On paper, the idea behind vinegar is sound. If your stomach is short of acid, add some. But vinegar also slows the stomach down.
When 10 people whose stomachs already emptied too slowly took apple cider vinegar with a meal, emptying slowed further. Vinegar does the same in healthy people, which is why it blunts the rise in blood sugar after a starchy meal, as How to Fix Blood Sugar Spikes Naturally explains. For blood sugar, that is useful. For a stomach that already feels full, it is the wrong direction.
Be sure not to drink it undiluted, either. It is strong enough to damage your teeth. 7 Fun and Tasty Ways to Stay Hydrated Without the Boredom has why vinegar softens enamel. The verdict is untested for indigestion, and possibly backwards for fullness.
5. Fennel
Fennel seeds are a staple at the end of Indian meals, for a reason. Called saunf, they are chewed raw or roasted after eating as mukhwas, a digestive and a breath freshener in one. Their sweet, aniseed taste comes from anethole, the same compound found in anise.
No human test of fennel for indigestion turned up. Its close cousin, caraway, is the partner in the peppermint capsules that worked. The verdict is pleasant and traditional, but untested.
What helps most
Put together, the plain changes are where I would start.
Look at your plate first. Cut down the fibre and the fermenting plant foods, and build the meal on meat, fish and eggs.
Think about acid. If your indigestion is worse with age, after years of acid blockers, or on a plant-heavy diet, low acid may be the problem, and the reflux article linked below has what to do about it.
Keep drinks between meals. Sip at the table, and drink your water when your stomach is empty.
Sit down for it. About 30% of a meal's acid is made before any food arrives, switched on by expecting the meal and by its smell and taste. A sandwich eaten over the keyboard skips part of that warm-up. That is our reading, but sitting down to eat costs nothing.
Eat less at a time, and slowly. A smaller meal gives a struggling stomach less to do, and leave a few hours before you lie down.
Leave gaps between meals. Your gut sweeps itself clean with a wave that runs only when the stomach is empty, and Why Snacking and Small Meals Can Sabotage Your Weight Loss has how grazing all day keeps sending it home.
Walk it off, and skip the digestif. After a large meal, brandy, herb liqueur, aquavit and espresso did nothing to help the stomach empty. A slow walk did. Neither changed how full people felt, so the walk is a small help, and it still beats the brandy.
Check the usual suspects. Painkillers like ibuprofen, alcohol, smoking and coffee, from the start of this article, are worth a hard look.
When to get it checked
Indigestion that keeps coming back deserves a proper look. Some signs mean it should be checked soon: severe pain, losing weight without trying, difficulty swallowing, being sick again and again, iron deficiency, a lump in your stomach, or blood in your vomit or stool. Most indigestion is harmless. These signs can mean something that is not.
Two other problems can pass for indigestion. Gallstones cause attacks of pain in the upper right belly, often after a fatty meal or at night, with nausea and sometimes vomiting, and they are more common in women and after 40. That is no reason to fear fat: the gallbladder empties when fat arrives, and What a Liver Detox Cannot Do That Your Liver Already Does has the near-fat-free diet that gave six of 11 people gallstones.
The other is the heart. A heart attack can feel like heartburn, with nausea, a cold sweat, breathlessness or feeling faint. Women, more often than men, have no chest pain at all, only pain in the neck or arm, or tiredness. If "indigestion" comes with any of those, treat it as an emergency, not a stomach ache.
A simple breath test can also show whether H. pylori is living in your stomach.
Back to the stone
That heavy stone after a meal is your stomach asking for less, not more. Fewer plants on the plate, less water in the glass, simpler meals, and enough acid to do the job.
Tonight, eat a plain meal of meat, drink your water well before it, and notice how your stomach feels afterwards.
Burning more than bloating? Acid Reflux: Why It Keeps Coming Back, and What Settles It — the valve, the pill that makes it come back, and the clues that point to too little acid.
Not sure which food is the culprit? Foods That Upset Your Gut: What's Real and What's Personal — what is hard on most guts, what is personal, and why some go quiet on meat alone.
Know someone who drinks a big glass of water with every meal and wonders why it sits heavy? Send them this before dinner.
Disclaimer: This article is general information. For advice about your own health or digestion, talk to a qualified health professional.
Affiliate Disclosure: This article contains affiliate links. As an Amazon Associate, All For Life earns from qualifying purchases, at no extra cost to you. We only link to products we would recommend without the commission.
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