500 years ago, before the era of mass production of sugar, fructose was at a minimum in the human diet. She acted only as part of a regular meal. Fruits, vegetables, grains, nuts / seeds and proteins contain a limited amount of fructose and provide a moderate amount of it. When the food industry isolated fructose from sources such as corn, and when it began to be added to a variety of processed foods, our fructose consumption increased.
In particular, it increased between 1970 and 2000. Although many people associate fructose with fruits, most of it comes to organisms from sources unrelated to them. A survey conducted in the 1990s showed that an average person consumes
80 grams of added sugar (which is
320 calories or 15% of energy consumption), about half of this amount is fructose.
We get fructose not only from fruits, but also from sucrose (tableted sugar). Sucrose is a diasaccharide (two sugars) consisting of glucose + fructose. It is found in processed foods, including sweets, soft drinks, and just about any packaged “edible food substance.”
What you need to know
Our liver is the main center of fructose metabolism. In the liver, it is processed into glucose derivatives and stored in the form of hepatic glycogen. At one time, the liver can process and store a limited amount of fructose as glycogen. The rest will be stored in the form of fat, so a large single dose of fructose is likely to settle on your sides. This is more pronounced in people with high blood lipids, insulin resistance, or type 2 diabetes.
High consumption of fructose (unlike other dietary carbohydrates) can lead to the fact that leptin will not be produced in normal quantities.
A decrease in leptin production due to chronic high fructose intake can have a detrimental effect on the regulation of food intake, as well as the percentage of body fat. In other words, when there is an excess of fructose, your brain will not send you “I have enough” signals, and you will continue to eat, although you have already received more than enough calories.
Since fructose is delayed in the liver, it does not cause a strong glycemic response. And if it can be good when consuming whole fruits, then if you eat added fructose-based sweeteners, the effect is the opposite. Although fructose is quite low on the glycemic scale and can help restore hepatic glycogen during physical activity, excessive consumption of it can lead to the formation of fat in the liver, as well as to an upset of energy balance and the body's fat regulation system. As a result, consuming large amounts of fructose-based sweeteners can lead to obesity in the abdominal region, low levels of healthy and high bad cholesterol in the blood, high triglycerides and loss of appetite control.
Clinical studies show that people who have a lot of fruits (and vegetables) in their diets tend to be more lean, it’s easier for them to maintain a healthy weight and overall well-being than those who don’t.
High fructose corn syrup
Since it is hotly debated by people associated with healthy eating, I decided to include it in the list. Like sucrose, syrup is glucose + fructose, but it contains slightly more fructose (55%) than glucose (45%). In this sense, syrup is no more dangerous than "real" sugar, or sucrose. There is even a study on this subject.
A few kind words about fructose.
Supporters of fructose argue that, since it is natural, it means healthy. They also point to the fact that fructose is much sweeter than table sugar, so much less is needed to sweeten it. As a result, with the same level of sweetness, fewer calories enter the body.
They also argue that the national obesity epidemic is not so much related to fructose, as obesity is the result of many factors, not just one. They cite several studies supporting this idea. We consume too much fructose. Much more than it would be necessary to just make something sweet: we need it to be SUPER sweet, and we will eat it in incredible quantities.
Fructose in food
Fructose-rich foods include many sweetened drinks and snacks, fruits, especially in concentrated juice or dried fruit form, and honey (see table below). Chains of molecules of fructose, fructooligosaccharides or fructans are present in high concentrations in some vegetables and grains, which often causes an allergic reaction in people with fructose intolerance.
To achieve this, seek the help of an experienced nutritionist who is competent in fructose intolerance. It is also often useful to drink vitamins.
In the case of hereditary fructose intolerance, it may be necessary to exclude sucrose (which, when split, produces fructose and glucose).
A sweetener such as tagatose is processed into fructose and is present in drinks (non-alcoholic, instant, teas, fruit or vegetable juices), breakfast cereals, cereal bars, confectionery and chewing gum, sweets and fillings, jams, marmalades and dietary products. Levulose and invert sugar on the labels indicate the presence of fructose.
Fructose is more easily tolerated in the presence of glucose. This means that the body is more likely to respond normally to products containing as much glucose as fructose (in the table, this is the F / G value, which should be less than 1).
In some products, regardless of glucose, a lot of fructose is also naturally present, i.e. more than 3 grams per serving, or more than 0.5 grams of fructans per serving.
These are two criteria that are considered most useful when choosing candidate products for removal from the diet.
According to these criteria, the following foods are most likely to be poorly tolerated and should be excluded from the diet or consumed in limited quantities:
- Fruit and fruit juices: apple, cherry, grapes, guava, lychee, mango, melon, watermelon, orange, papaya, pear, persimmon, pineapple, quince, carambola.
- Most dried fruits, including currants, dates, figs, raisins, even if it is a fitness bar.
- Processed fruits: kebab / grill sauce, chutney, canned fruits (often made in peach juice), plum sauce, sweet and sour sauce, tomato paste.
- Berries in large quantities: blueberries, raspberries.
- Sweets, foods and drinks with a very high content of sucrose (table sugar) and fructose corn syrup.
- Honey, maple syrup.
- Large quantities of vegetables (containing fructans or inulin: artichoke, asparagus, beans, broccoli, cabbage, chicory, dandelion leaves, garlic, leeks, onions, peanuts, tomatoes, zucchini.
- Sweet wines: for example, dessert wines, a butcher, port, sherry.
- Wheat and rye products (with fructan content): flour, pasta, bread, wheat bran, whole breakfast cereals.
- Wholemeal foods in large quantities.
- Since people with fructose intolerance react poorly to sorbitol (code E420) and xylitol (E967), it is better to check whether the following foods cause undesirable symptoms: diet / light drinks and drinks for diabetics, chewing gum and diet sweets / candies without sugar , stone fruits (e.g. apricots, cherries, quinces, prunes and peaches), pears, dried fruits (e.g. apples, apricots, pigs, figs, nectarine, peaches, plums, raisins). Beer in large quantities can also cause problems.
Examples of well-tolerated fruits and vegetables are:
Eggplant, banana, Brussels sprouts, carrots, clementine / mandarin, corn, cucumber, fennel, grapefruit, lemon, potatoes, pumpkin, radishes, red currants, rhubarb, sauerkraut, spinach and sweet potatoes / pits.
In the case of multiple intolerances of carbohydrates / sugar, FODMAP intolerance (fermentable oligo-, di-, monosaccharides and polyols) may occur, which requires a general decrease in the content of FODMAP, at least during the trial period of 4-6 weeks and with observation for a diet. For a significant group of patients, however, this is not necessary, since individual intolerances are more common.
The table below shows the content of fructose and glucose, as well as their ratio in the most common products. The numbers are rounded, and therefore discrepancies between the values of fructose and glucose and their ratio are possible. Keep in mind that when comparing tables from different sources, certain variations are possible. This is due to differences in measurement methods, the actual sugar content in different types of fruits, as well as ripening and growth conditions. Therefore, these tables should always be considered as rough guidelines.
First step: we look at the ratio of fructose and glucose (F / G value), it should be less than 1 (i.e., the fructose in the product is less than glucose).
Second step: the absolute fructose content in the product should not exceed 3 grams per serving. Small portions of border products are acceptable, but not on an empty stomach.
Content per 100 g of product (in grams):
|Berries||Fructose (F)||Glucose (G)||F / G ratio|
|Black currant, fresh||3||3||1|
|Currant red, fresh||2||2||1.2|
Content per 100 g of product (in grams):
|Dried fruits||Fructose (F)||Glucose (G)||F / G ratio|
Honey and fruit
Content per 100 g of product (in grams):
|Honey, fruits||Fructose (F)||Glucose (G)||F / G ratio|
|Grapefruit juice, fresh||2||2||1|
|Fresh orange juice||3||3||1.2|
Vegetables and mushrooms
Content per 100 g of product (in grams):
|Vegetables, mushrooms||Fructose (F)||Glucose (G)||F / G ratio|
|Whole rye bread||1||1||1.5|
Sweeteners: aspartame, acesulfame K, saccharin, cyclamate, stevia and thaumatin do not cause problems for people with fructose intolerance, including hereditary.
Sorbitol decreases, and glucose increases fructose tolerance.
Glucose (e.g. glucose / dextrose preparations, drinks, syrups) can be consumed with products containing fructose to increase tolerance.
Products containing fructose are best tolerated in small portions throughout the day and not on an empty stomach.
About 30% of people with fructose intolerance also suffer from lactose intolerance. They are likely to be sensitive to the entire FODMAP group.
What is maltose?
Most sugars are short chains made up of smaller sugar molecules that act as building blocks. Maltose consists of two units of glucose. Table sugar, also known as sucrose, consists of one glucose molecule and one fructose molecule.
Maltose can be obtained by breaking down starch, the long chain of many units of glucose. Enzymes in the intestine break down these glucose chains into maltose (1).
Plant seeds also produce enzymes to release sugar from starch when they germinate.
People have long used this natural process for food.
For example, during malting, grains germinate in water and then dry. This activates the enzymes in the grains to release maltose and other sugars and proteins.
Sugar and proteins contained in malt are very nutritious for yeast, therefore malt plays an important role in brewing, production of whiskey and malt vinegar.
Malt grains are also used in sweets and desserts as sweeteners.
Maltose can be bought in the form of dry crystals, where beer is sold, or in the form of syrup. Typically, the syrup is made from corn, but it cannot be mistaken for high fructose corn syrup.
You can use maltose in recipes as a substitute for other 1: 1 sugars. Maltose is not as sweet as sucrose or fructose, so in some recipes a slightly larger amount may be required to obtain the desired taste.
Maltose is created by breaking down starch. This occurs in the intestines after you have eaten starch, as well as in seeds and other plants when they begin to germinate. This sugar is important in brewing and is used as a sweetener.
High Maltose Foods
Some foods contain maltose (2).
You can find it in wheat, corn, barley and several ancient cereals. Many breakfast cereals also contain malt grains to add natural sweetness.
Fruits are another common source of maltose in the diet, especially peaches and pears. Sweet potatoes (sweet potato) contain more maltose than most other foods, due to their sweet taste.
Most syrups get sweet from maltose. High maltose corn syrup provides 50% or more sugar in the form of maltose. This is useful in making caramel and an inexpensive sweetener.
Maltose is found in starchy grains, vegetables and fruits. It is useful as an inexpensive sugar source in the form of high maltose corn syrup.
What is more beneficial than maltose or table sugar?
People commonly use sucrose, also known as table sugar, to cook and sweeten foods. This is another short chain of two sugars, consisting of one glucose molecule linked to one fructose molecule.
Since sucrose contains both of these sugars, its health effects are probably somewhere between glucose and fructose.
However, fructose has more serious health effects and is not metabolized like glucose.
A diet high in fructose can lead to a more rapid onset of obesity, insulin resistance, and diabetes mellitus (3).
Since maltose consists only of glucose and not fructose, it may be a little healthier than table sugar. However, no studies have investigated the effects of fructose substitution with maltose, and more studies are needed.
Maltose does not contain fructose, like table sugar. Therefore, replacing table sugar with maltose in your diet will help you avoid the known health effects of too much fructose. However, the health effects of maltose are not well understood.
High maltose corn syrup and high fructose corn syrup: which is healthier?
Some people think table sugar is healthier than the often demonized high fructose corn syrup.
But in fact, their fructose content is very similar. Table sugar contains exactly 50% glucose and 50% fructose, while high fructose corn syrup contains about 55% fructose and 45% glucose.
This small difference hardly makes table sugar more healthy than high fructose corn syrup (4).
Food companies tried to avoid growing negative public perceptions of fructose by replacing high fructose corn syrup with high maltose corn syrup.
And they may be right about that. If maltose is used to replace the same amount of fructose, grams per gram, this may be a slightly healthier option.
As a rule, corn syrups with a high content of maltose and fructose can replace each other in a ratio of 1: 1, but individual products can vary.
The fact that fructose may be a little worse for you does not necessarily make maltose healthy. Keep in mind that maltose is still sugar and should be used in moderation.
Replacing high fructose corn syrup with high maltose corn syrup can have little health benefit as it will reduce fructose intake. However, there is no convincing research, so more new data is needed.
Is maltose harmful to you?
Research on the effects of maltose on health has not been conducted.
Since the majority of maltose breaks down into glucose during digestion, its health effects are probably similar to other sources of glucose (5).
In terms of nutritional value, maltose provides the same amount of calories as starches and other sugars.
Your muscles, liver and brain can convert glucose to energy.In fact, the brain receives energy almost exclusively from glucose. When these energy needs are satisfied, any remaining glucose in the blood turns into lipids and accumulates in the form of fat (6).
As with other sugars, when you consume maltose in moderation, your body uses it for energy, and it does no harm (7, 8, 9).
However, if you consume maltose in excess, it can lead to obesity, diabetes and heart disease, like other sugars (3).
Maltose, like most nutrients, is precisely the high level of consumption that makes it harmful.
Research is limited, but the health effects of maltose are likely similar to those of other sugars. Thus, moderate consumption of maltose is not harmful.