"Low-sugar" mooncakes cause diarrhea? Thanks for the invitation! The culprit turned out to be this

Expert of this article: Pa Lize, chief physician of nutrition, former deputy director of the Institute of Chronic Disease Prevention and Health Management of Xinjiang Uygur Autonomous Region Center for Disease Control and Prevention

The Mid-Autumn Festival is approaching, and it is time for family reunion, moon watching and moon cakes.

Nowadays, driven by the concept of healthy consumption, more and more friends will choose to buy sugar-free or sugar-substitute foods, and mooncakes, which are high in calories, naturally have to launch products that conform to the trend.

Recently, many netizens said that they started to have stomach upset after eating Zhihu's "healthy low-sugar mooncakes".

Afterwards, the official apologized and explained that during the purchasing process, they chose low-sugar mooncakes that used maltitol instead of sucrose, which caused some people to be intolerant and experience discomfort symptoms such as diarrhea.

Weibo screenshot

Many people have questions: What is maltitol? Why does it cause diarrhea after eating it? Is adding maltitol to food really sugar-free? This popular science article will help you solve the mystery.

Why is maltitol added to mooncakes?

Maltitol (English name Maltitol) is a disaccharide alcohol obtained by hydrolysis, hydrogenation and refining of starch. It is a white crystalline powder or a colorless, transparent, neutral viscous liquid and is a functional sweetener food.

Maltitol is a sucrose substitute and is usually used as a sugar substitute. Adding maltitol to mooncakes is not done by companies to reduce costs.

Maltitol is used as a mooncake ingredient because its chemical and physical properties can greatly improve the quality of mooncakes. For example:

(1) Maltitol can ensure that mooncakes have better viscosity;

(2) The hygroscopicity of maltitol improves the water retention of mooncakes while preventing the crystallization of sucrose;

(3) Maltitol is heat-resistant and will not undergo the Maillard reaction (a phenomenon in which sugar (carbohydrate) and protein (amino acid) foods turn brown at high temperatures) after heating, thus changing the color of the product.

(4) As a sweetener, maltitol is basically as sweet as sucrose (80%-95% of the sweetness of sucrose), but its calories are only 1-5% of sucrose. This just meets the needs of the increasing number of people who are seeking sugar-free labels and "zero-calorie" foods. Therefore, it is often promoted as a "zero-calorie" food.

Why does eating mooncakes containing maltitol cause diarrhea?

Although the advantages of maltitol are recognized and have been widely used in food ingredients such as cakes, candies, and dairy products around the world, it can only be partially digested in the human body and has an extremely low absorption rate, which can easily cause an increase in osmotic pressure in the large intestine, making it difficult for water to be absorbed by the intestines.

Therefore, if the human body consumes excessive amounts of maltitol, it will cause stomach cramps and bloating, and symptoms of gastrointestinal discomfort such as intestinal rumbling and diarrhea.

Although there are literature reports that gastrointestinal discomfort symptoms will occur only when the intake exceeds 100g/person/day, due to individual differences, diarrhea symptoms may occur even if this amount is not reached. In particular, the incidence of sugar alcohol malabsorption is relatively higher in people with chronic gastrointestinal inflammatory diseases, and the symptoms that occur will also be more severe.

In addition, some studies have shown that consuming foods containing maltitol with other carbohydrates can aggravate gastrointestinal discomfort symptoms.

This downside of maltitol is listed on some product labels as a "potent laxative" warning.

Are sugar-free foods containing maltitol really sugar-free?

In fact, the fact that many sugar-free and sugar-substitute foods contain maltitol does not mean they are really sugar-free.

This is because although no sugar is added to the food, the taste is improved by using maltitol or other sugar alcohols as sweeteners. People will unknowingly consume more refined carbohydrates, such as biscuits, pastries, etc., or consume sugar-free but high-fat milk tea, sugar-free chocolate, etc., which adds extra energy.

In addition, my country's "General Rules for Nutrition Labeling of Pre-packaged Foods" stipulates that food can be labeled as sugar-free if the sugar content is less than 0.5g/100g.

From this we can see that “sugar-free” or “sugar substitute” is not really healthy!

In addition, it is worth noting that:

Given that the digestion method of maltitol is different from that of most other sweet carbohydrates that people are accustomed to eating, it is only partially digested in the small intestine and enters the colon. Its glycemic index (GI) is 35, which is much lower than the glycemic index of 65 for ordinary white sugar. Therefore, there are many advertisements claiming that it can be used as a temporary sugar craving for people with diabetes.

However, maltitol is also a carbohydrate. Diabetics should never eat foods sweetened with maltitol, such as drinks, chocolate, donuts, puffs, cream cakes, etc. Remember that large amounts of maltitol will cause blood sugar fluctuations and affect insulin sensitivity.

Which products are better to add maltitol?

Another important selling point of maltose sweetener is that it does not stick to teeth and cause tooth decay, has a mellow sweetness without aftertaste, and is relatively safe to use within the standard range. Therefore, it is also used in mouthwash, chewing gum and even toothpaste. It does not affect oral health and can also improve the taste of the product.