How to Thicken Drinks to Prevent Aspiration: Five Points for Using Thickeners Safely

Written by: 稲山 未来 (Registered Dietitian)

Have you ever heard that people whose swallowing function has declined should “use a thickener in their drinks”? But why is thickening necessary? And did you know that some drinks thicken easily while others do not? In this column, let’s look at thickening agents.

What is aspiration?

Our throat connects to two passages: the trachea (windpipe), which carries air to the lungs, and the esophagus, which carries food and drink to the stomach.

When we breathe normally, the entrance to the windpipe is open and the esophagus is closed. Only at the moment we swallow does the windpipe close and the esophagus open instead.

It’s easy to check for yourself. Can you swallow while breathing in or out? You always have to stop breathing for an instant, don’t you?

As the muscles of the throat weaken with age, the timing of drinks or food reaching the throat and the timing of closing the windpipe can fall out of sync. When that happens, drinks slip into the windpipe through the gap and eventually reach the lungs.

The lungs are organs meant to take in air, so when food or drink gets in, they treat it as a foreign body and become inflamed. This is aspiration pneumonia: inflammation of the lungs caused by aspiration.

Why is thickening necessary?

Liquids are easy to aspirate, so some kind of measure is needed to prevent aspiration.

Our throat has a reflex called the swallowing reflex: when food or drink comes near the windpipe, we swallow automatically, without thinking. It works the same way as instinctively putting out a hand when we are about to fall.

With age, however, it takes longer for the throat to swallow after sensing that “a drink has come near the windpipe!” As a result, with drinks that pass through the throat quickly, the swallow comes too late. In other words, if the flow is slowed down, even a slow swallow can keep up.

Thickening drinks means slowing down their flow in this way.

For example, imagine letting tap water run onto a tilted cutting board. It runs straight off. That is how fast water flows. Now pour honey onto a cutting board at the same angle. Can you picture it flowing more slowly than the water?

When the flow is slow like this, it is easier to time the closing of the windpipe.

Cautions about thickening

Thickening is used to slow the flow of drinks, but if it isn’t done well, it can actually increase the danger, so care is needed.

Now pour custard cream onto the same cutting board. Does it flow? It sticks to the board, doesn’t it?

If a drink is over-thickened, it becomes adhesive and tends to stick to the throat. Because the person’s swallowing strength is weak, they can’t push what has stuck to the throat into the esophagus, and it stays around the throat.

Finally, pour strawberry jam with whole pieces of fruit onto the cutting board. This time, the pieces of strawberry stay on the board. This is similar to what happens when the thickener doesn’t mix evenly and leaves lumps. Like the lumps that form in potato-starch slurry, these also tend to stick to the throat.

What’s more, thickener lumps are sticky balls. If one sticks tightly over the opening of the windpipe, in the worst case it can block the airway and cause choking.

Thickeners are very useful, but if they aren’t used well, they come with dangers like these.

How to thicken drinks

Now that you know why thickening is needed and what the dangers are, what matters is how to thicken.

Thickeners are now sold in drugstores, by mail order and online.

The most important thing is to read the instructions and recommended amounts on the package carefully before use. Then keep the following points in mind.

Point 1: Always use the same type of thickener

Thickeners are sold by various care food manufacturers, and the right amount differs by maker and type. To avoid “I used the same amount as always, but it came out far too thick,” always use the same type of thickener.

Point 2: Use the same cup and the same spoon

This is similar to Point 1, but another important way to get the same thickness every time is to keep the amounts constant. To keep the amount of liquid constant, use the same cup whenever possible. In the same way, use the same spoon to measure the thickener and decide, for example, “one level spoonful of this spoon.”

Point 3: Add the thickener little by little while stirring the liquid with a spoon

When adding thickener, add it a little at a time while stirring the liquid with a spoon. Following this step carefully prevents lumps. “Add while stirring” is the basic rule, so remember it.

Point 4: You can’t make a drink thicker afterward

After thickening a drink, you may sometimes want it a little thicker. But adding more thickener to a liquid that has already thickened creates lumps. If you want it thicker, make a more concentrated thickened liquid in a separate container and mix it with the original drink.

Point 5: Some drinks are harder to thicken

Recommended amounts of thickener are usually given for tea. Drinks that are harder to thicken include salty miso soup, protein-rich milk and nutritional supplement drinks, and acidic juices.

“Harder to thicken” means that it takes longer for the thickness to stabilize. When thickening such drinks, we recommend the stir-twice method: add the thickener and stir, let it stand for about 10 minutes, then stir well again before drinking. Letting it stand helps the thickness stabilize, so rather than adding more thickener, be patient and wait for it to settle.

Summary

The thickness of a drink can be changed by the amount of thickener used, and it is important to match the thickness to the person’s swallowing function. To find the right thickness, consult a professional who assesses swallowing function, such as a dentist or a speech-language-hearing therapist.

Use thickeners well to prevent aspiration and help the person enjoy their meals.

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About the author: 稲山 未来 (Registered Dietitian)

This article is a contribution from a medical or care professional, re-edited by our editorial team. It provides general information as of the time of writing, and symptoms and circumstances differ from person to person. For specific decisions, please consult your doctor, dentist, pharmacist or another professional.

This is an English translation of a column originally published in Japanese by Next Co., Ltd.

About Next Co., Ltd. We are a Tokyo-based company working in Japan’s senior care and end-of-life planning field. Alongside these expert columns, we publish professional training textbooks and support businesses entering Japan’s eldercare market. More expert columns | Our English textbook | Contact us