Brief Talk on Fructose and Fructose Syrup

The publication of the Draft for comments of "National Food Safety Standards General Rules for Nutrition Labeling of Prepackaged Food" (hereafter "Draft"), issued by National Health Commission of the P.R.C on September 26, 2021, gives us the occasion to tackle the hot and interesting of fructose and fructose syrup. You might recall that information on sugar in food was provided in our short popular article released recently.

Sugar

Compared with current national standard, the most important change in the Draft is the minimum mandatory information required for nutritional labelling. Such mandatory information on nutritional labeling is changed from 1+4 (energy + protein, fat, carbohydrate, sodium) to 1+6 (energy +protein, fat, saturated fat -or saturated fatty acid-, carbohydrate, sugar, sodium).

Saturated fat and sugar are added in the Draft: this is welcome by many since it seems very important for consumers to effectively reduce potential risks of "tricky" claims (e.g. "no added sugar", "no added sucrose" and "no sucrose"). With the new standard as it is now consumers will be allowed more easily to figure out the amount of sugar by checking the "sugar" content on the nutrition label.

Labeling sugar content is not mandatory in the current rules, the so-called "sucrose free" food may have fructose as components and the actual sugar content is not that low. Furthermore, the so-called "0 sugar" claim means that the sugar content is no more than 0.5 g per 100 g (solid) or 100 ml (liquid) instead of zero sugar.

The Draft gives a more specific and easier to understand definition on "sugar", which refers to the sum of monosaccharides and disaccharides (excluding sugar alcohols), and the sugar to be listed in the nutrition label need to refer to the sum of glucose, fructose, sucrose and maltose in food. Sucrose is only a part of "sugar" in nutrition labels.

It should be noted that the daily intake of sugar is not specified in the Draft. And this is intended to avoid the possible misunderstanding from consumers that a certain amount of sugar must be consumed every day. Experts generally agree that adults need about 2000 calories a day, of which the energy from added sugar should not exceed 10% of the total energy intake a day, therefore the upper limit of adding sugar is 200 calories. One gram of sugar contains about 4 calories of energy: that means the daily intake of sugar for normal people should not exceed 50 grams. Doctors might suggest staying safely above the threshold and to reduce the daily sugar intake to 25 grams.

Fructose

Fructose is a monosaccharide, which is an isomer of glucose and is present in fruit paste/juice and honey in free state. The product of fructose and glucose is sucrose. Fructose is the main sugar additive used in processed food and soft drinks. Fructose is the sweetest of all natural sugars and its sweetness is 1.8 times that of sucrose. Under the same sweetness standard, the amount of fructose is only half of that of sucrose. Therefore, fructos eis often used as sweetener in fruit juice, beverage, dessert, ice cream, candy, etc.

Although fructose can, compared with sucrose, reduce calories intake under the same sweetness and its glycemic index is also very low, the main metabolism of fructose is in the liver. The metabolism of fructose in the liver is not limited to the control of rate-limiting enzymes and it will produce a large amount of glucose, glycogen, lactic acid, and pyruvate. Lactic acid and pyruvate are precursors for the synthesis of triglycerides. Therefore, long-term excessive intake of fructose might lead to fatty liver and obesity. Moreover, based on animal experiments, fructose can cause the decrease of insulin sensitivity in multiple organs, resulting in systemic insulin resistance and metabolic syndrome.

The decomposition process of fructose in the body will directly produce uric acid. At the same time, fructose will reduce the excretion of renal uric acid, further resulting in the increase of uric acid in the body. Under this dual influence, the level of uric acid in the human body remains high. It is well known that excessive intake of purine will increase the uric acid in the human body. The fact that excessive intake of fructose might lead to high uric acid also cannot be ignored.

Fructose Syrup

Fructose syrup is a sweetener obtained from corn starch by enzymatic hydrolysis. It is named fructose syrup because it has both glucose and fructose. According to the proportion of fructose, fructose syrup can be divided into three categories, that is

No. 42 fructose syrup is suitable for making cakes and biscuits, while No. 55 fructose is more suitable for making frozen drinks and soft drinks. No. 90 fructose syrup is not common in daily life because of its high fructose content and high sweetness.

Fructose syrup is used by many food manufacturers because of its low cost, high sweetness, easy fermentation, good coloring and long shelf life and since 1970 became popular all over the world. Since then, fructose syrup has been used in most of the processed food products, such as cakes, biscuits, fruit juice, ketchup and canned food, regardless of whether it contains sugar or not.

The excess intake of fructose can bring a huge metabolic burden to the human body, especially the liver. Compared with glucose with more complex metabolic pathways in vivo, fructose can be absorbed by the liver more easily. Excessive intake of fructose will promote fat synthesis and increase the risk of obesity, diabetes, hypertension, and other diseases.

The fructose in fresh fruit is wrapped in dietary fiber, and its absorption speed is slow. The liquid fructose in fructose syrup can be absorbed by the human body at a faster speed after entering the human body. Once a large amount of food containing fructose syrup is taken, more fat will gradually gather around the liver and increase the risk of fatty liver. The risk of obesity will be high for people fond of food with high fructose syrup content. Studies show that those who drink at least one cup of beverage containing fructose syrup a day has a 55% higher risk of non alcoholic fatty liver than those who do not drink.

The ingredient list on the package will now show if the product contains "fructose syrup" or not. Thanks to the new Draft, we’ll be able to check properly the label to not be misled by so-called "0 sucrose".

As usual, we always welcome any corrections and suggestions! Thanks for your support!

(translated by Karen Wang)

_{Cover photo by Leeloo Thefirst on Pexels}