Is fructose bad for you? Is it true that it damages the liver and makes us gain weight?

It was always thought that fructose acted differently from glucose, and had a negative impact on health.
Fructose, a sugar widely found in fruit and honey, has been heavily demonized in recent years for the reasons listed below.

1. Because in industrial foods it is very present in the form of glucose-fructose syrup or corn syrup .
2. As it increases uric acid concentrations , and this negatively impacts the liver ( source ).
3. Because unlike glucose it has always been thought that fructose could only be converted into hepatic glycogen, but not taken directly from the cells that needed it.
4. Due to the fact that fructose generally ferments in the intestine, therefore people with intestinal problems have difficulty digesting foods rich in fructose, such as honey and some types of fruit.

However, this has led people to significantly limit the consumption of fruit , thinking that it is bad and that it can lead to a greater risk of obesity, metabolic syndrome and non-alcoholic fatty liver disease.
But is it really so? Is fructose bad for you?
Well, not exactly.

IS FRUCTOSE HARMFUL?
HERE ARE THE LIMITS OF STUDIES AGAINST FRUCTOSE

The main limitations of the studies that have analyzed the negative impact of fructose on health have two problems: one the quality of fructose, the other the quantity.

In all the studies , the negative impact of fructose in liquid form was analyzed, and in an amount of 25% of the total daily calories of the subjects, who however were subjected to an uncontrolled non-normocaloric diet .

In other studies, like this one, for example, teenagers were told to consume drinks rich in fructose glucose syrup, regardless of their diet .
The researchers then used simple questionnaires to figure out how much fructose they had taken.
It is difficult to assess a connection if I do not know the rest of the diet that the participants have made, and especially if I have encouraged them to consume drinks with syrup instead of eating fruit.

To be clear, in this study , to prove that fructose was bad for you, the scientists encouraged the consumption of 8 cans of sugary drinks per day . A little bit much. As with all foods, the dose makes the poison.

Can we say that, for example, vegetables are good for you?
You will all say yes.
But what if I eat 5-6 kilos of vegetables a day?
If a study used this method to say that vegetables are bad, wouldn’t that seem a bit of a risky conclusion?

But it doesn’t stop there.
Instead, one study subjected participants to greater consumption of candy, which contained both glucose and fructose, to see if this led to worsening liver health and an increase in visceral body fat, so let’s say, abdomen. The subjects were evaluated for 5 years in a row and subjected to periodic checks.

Result? They are not fattened.
Cholesterol, triglycerides, transaminases and inflammation markers all decreased by 15 to 19%.
How can this be explained? It is explained by the fact that the candies were not pure fructose, but in combination with glucose. Glucose promotes the correct absorption of fructose.

While in the other studies, participants consumed pure fructose in liquid form.
In mice it was injected directly into the liver.

Now: fruit contains both glucose and fructose. Eating fruit is not like drinking liquid fructose.
So let’s see what happens when we eat a food that contains fructose