Why Chewing Matters — and How Refined Carbs and Liquid Fructose Undo It

Most people give chewing little thought. We treat it as one step in digestion, a simple aid to breaking food down — and leave it there. But the act of chewing is a foundation for a healthy body and mind. In Korean Traditional Medicine (KTM), the traditional healing system of Korea also known as Hanbang (한방), and in modern research alike, how we chew turns out to matter far more than it seems — and two staples of the modern diet, refined carbohydrates and liquid fructose, quietly undo its benefits.

In Summary

The Donguibogam distinguishes drinking, which nourishes qi, from chewing, which nourishes both qi and blood (기혈) — making chewing a source of the body’s energy.
When refined carbs and liquid fructose cut down how much we chew, qi and blood are under-produced — and, in KTM terms, excess dampness (濕) can build up and stall fluid metabolism, dragging down overall function.
Modern research links proper chewing to increased blood flow to the brain, better cognition, and a more responsive nervous system.
Refined carbs and liquid fructose are easily digested and barely need chewing, so they reduce that stimulation — dulling nervous-system responsiveness and disturbing digestion.
Chewing is the true first step of digestion: well-chewed food digests better, curbs excess stomach acid, and helps enzymes work efficiently. Limiting refined carbs and liquid fructose is the practical takeaway.

The Korean-Medicine View: Chewing Builds Qi and Blood

The Donguibogam (東醫寶鑑), the great classic of Korean medicine, remarks on the special nature of chewing. Drinking and chewing are both sources from which the body’s energy — its qi and blood (기혈) — is generated, but they are not the same: drinking nourishes qi, while chewing nourishes qi and blood. When liquid fructose and refined carbohydrates reduce how much we chew, that generation of qi and blood falters. And there is a second problem: as this happens, the body can slide into a state of excess dampness (습, 濕), and when dampness stalls the metabolism of fluids, overall bodily function drops considerably.

What Chewing Does for the Brain and Nerves

The daily act of chewing is more than the opening move of digestion — it helps maintain and improve brain function, the nervous system, and digestive health. Research finds that adequate chewing increases blood flow to the brain and sharpens cognitive ability, with positive effects on memory and learning that carry into many parts of daily life. Chewing also improves the responsiveness of the nervous system, contributing to overall neurological health. In other words, the jaw is doing quiet work for the brain every time you eat.

How Refined Carbs and Liquid Fructose Undo It

Refined carbohydrates and liquid fructose interfere with all of this. Because they are so easily digested, they tend to cut down the amount we chew. Taken in without enough chewing, they lower the responsiveness of the nervous system and disturb the digestive process, which can lead to indigestion. And food swallowed without proper chewing fails to deliver the stimulation the brain needs for that boost in blood flow and cognition. The very ease of these foods is what strips away the benefit that chewing would otherwise provide.

Chewing Is the First Step of Digestion

Chewing is where digestion actually begins. Well-chewed food is digested more easily and is kinder to the whole digestive tract: it helps prevent the over-secretion of stomach acid and promotes the efficient action of digestive enzymes. Together these improve overall digestive health and help head off digestive complaints before they start. So the practical conclusion is straightforward — chewing matters to your whole-body health, and a healthy diet means limiting refined carbohydrates and liquid fructose in particular. If you love refined carbs too much to give them up, you will need to put in a matching amount of high-intensity exercise.

In Summary

Chewing is not a trivial preliminary; it is, in the classical view, a source of qi and blood, and in the modern one a stimulus for brain blood flow, cognition, and nervous-system health. Refined carbohydrates and liquid fructose undo that by requiring almost no chewing — under-producing qi and blood, letting dampness accumulate, and dulling both nerves and digestion. Chew your food well, and rein in the refined carbs and liquid fructose. It is one of the simplest levers you have on your metabolic health.

This article reflects the clinical observations and teaching practice of Professor Seungho Baek, Professor of Korean Medicine at Dongguk University College of Korean Medicine, specializing in Pathology and Oncology.