Many people with weak gastrointestinal function have the experience that after eating more fruit, their stomachs become uncomfortable and they are very prone to diarrhea, which can even lead to acute intestinal inflammatory episodes. In addition to the reason that dietary fiber in fruits promotes excessive intestinal movement, it is likely that it is also related to the fact that excessive intake of fructose can lead to an inflammatory response in the intestine. In turn, a compromised intestinal barrier and decreased digestion and absorption are entwined with intestinal flora disorders, causing the body to become weak and to react with intolerance to a wide range of foods.
Large amounts of fructose also cause fatty deposits in the liver and the development of a fatty liver, while also producing metabolic disorders that reduce insulin sensitivity and increase the risk of diabetes. Excessive fructose intake also causes an increase in endogenous purines (suggesting enhanced catabolism in the body) and elevated uric acid, increasing the risk of gout. These are all previously confirmed findings. In short, it’s true that large amounts of fructose are bad for your health.
So, why did everyone say that fruit is good for health? Then we need to talk to you about six points of knowledge.
Knowledge point 1: fructose means “sugar in fruit”?
The sugar in fruit consists of three parts: glucose, fructose and sucrose, of which fructose is only one. Fructose is not a vague concept of “sugar in fruits”, but a monosaccharide with a defined structure, a sugar different from glucose, sucrose and maltose.
Knowledge point 2: Which fruits have a high percentage of fructose in their sugar content?
Some fruits have a larger proportion of sucrose, such as dates and peaches; some fruits have a larger proportion of glucose and fructose, such as watermelon and grapes. Generally speaking, the amount of glucose and fructose in fruits is basically equal.
Fructose gives a fresh and refreshing sweetness, and has the property of sweetening at low temperature. Sucrose, on the other hand, does not have this property, and its sweetness is similar at any temperature. Any fruit that feels sweeter when iced, as well as fruit that tastes especially refreshingly sweet, is almost always fruit with a higher fructose ratio.
Knowledge point 3: Eating white sugar and honey will also increase the fructose in the body
In terms of plant metabolism, photosynthesis synthesizes glucose first, and then glucose can be isomerized into fructose. One molecule of glucose and one molecule of fructose combine to produce one molecule of sucrose, which is the white sugar that you eat every day, and one molecule of sucrose is hydrolyzed in the intestine by sucrase, which in turn produces one molecule of glucose and one molecule of fructose.
The sugar we eat at home every day, including white sugar, white sugar, brown sugar, rock sugar, brown sugar, etc., is mainly composed of sucrose. So, after digestion and absorption in the intestine, sweetened foods bring both glucose and fructose.
Honey also has three types of sugars: sucrose, fructose and glucose. Generally speaking, the easier it is to crystallize and precipitate honey, the greater the proportion of glucose in it; the less likely it is to crystallize and precipitate honey in winter, the greater the proportion of fructose. This is because fructose is the most soluble, sucrose is the second most soluble, and glucose is the lowest.
Knowledge point 4: Where does “industrially produced fructose” come from?
In the modern starch sugar industry, corn is first processed to extract starch, then corn starch is hydrolyzed to produce glucose, and glucose isomerase is used to partially transform glucose into fructose, resulting in high fructose glucose syrup. The industrialized fructoglucose syrup can reach up to 90% fructose ratio.
Fructose syrup has a sweet taste and is more refreshing when chilled, so it is used as the main source of sweetness in various sweet drinks such as Coke and Sprite. It is also used in many dessert stores to prepare drinks. So, among people who like to drink sweet drinks, sweet drinks are the biggest source of fructose.
A 500 ml bottle of sweet drink will have about 50 grams of added sugar (sucrose or fructose syrup). At half fructose, that’s about 25 grams of fructose. So, drinking sweet drinks will inevitably give your body too much sugar, and you will get quite a lot of fructose.
The fructose obtained from drinking drinks, the small amount of sugar obtained when drinking yogurt, the small amount of sugar put in cooking, plus the fructose obtained when eating fruits normally, add up to the fructose intake is inevitably too much.
Knowledge point 5: How much sugar is in fruits?
Traditionally, it is said that a certain fruit has less sugar, but it may not be accurate. Because the data in the food composition table are measured long ago and do not cover all new varieties of fruits, they often do not represent the sugar content of fruits on the market. Some fruits are naturally high in sugar. For example, sweet grapes can have a sugar content of 16% to 20%, with 40% to 50% fructose. By this calculation, eating 500 grams of grapes with 18% sugar content will give you 90 grams of sugar, of which there are 36 to 45 grams of fructose.
There are also tropical fruits that we love to eat, and the sugar content is also considerable. Look at the sugar content of local fruits as measured by Thai scholars: mangosteen 17.5%, rambutan 18.5%, mango 13.9%, lychee 17.9%, pineapple honey 19.2%, and fenugreek 17.2%.
However, those fruits that were not so high in sugar are now gradually being replaced by high-sugar varieties, so the sugar intake from fruits is getting higher and higher. Iced sugar oranges, sand sugar oranges, iced sugar heart apples, etc., all with “sugar more sweet taste” as a selling point. Since fructose tastes sweet and delicious, fruit varieties with high fructose content are also more popular, which makes the fructose eaten from fruits also more and more.
For example, our research measurements last year found that a certain kind of Fuji apple contains 8.3% fructose and 6.7% glucose. At this level of sugar, apples can’t really be called low-sugar fruit. At this point, you must have understood: eating a small amount of fruit is beneficial, not the same as eating a large amount of fruit is beneficial. Eating a lot of fruit, or drinking fruit juice at will, can also lead to excess fructose!
Knowledge point 6: eating more fructose is harmful, will eating less be harmful?
A small amount of fructose intake may be beneficial to health, such as the glucose metabolism of the liver is beneficial. In combination with starchy foods, a small intake of fructose without increasing the total amount of carbohydrates can help reduce glycated hemoglobin levels. However, a large intake is counterproductive.
Some studies suggest that too much or too little fruit is not good in terms of preventing diabetes, and that two to three hundred grams is the right amount.
A few ways to reduce the harmful effects of fructose
Avoid drinking any sweet drinks.
2. Add less sugar to daily family meals, drink porridge and soup without sugar as much as possible, including honey in strict limits.
3. Choose foods such as yogurt with low sugar content.
4. The amount of fruit is 200~350 grams per day (peeled and cored amount), do not often eat to more than 1 pound.
5. Do not be overly obsessed with the strong sweetness when eating fruit, and the amount of sweet fruits should be reduced as appropriate.
6. Do not drink a lot of juice, even if it is 100% juice. Juice squeezed by yourself is the same.
7. Fruit can be used as a substitute for sweets, or as a substitute for some cold dishes, and eaten in small quantities at meals, so as to avoid overdose, but also to play a small amount of fructose to promote the role of glucose metabolism.
8. Do not buy commercially available home fructose products because of low fructose glucose metabolism.
