Glycemic Index of Fructose
Potential Benefits of Fructose
The relationship between fructose and diabetes is a troubled relationship, which in recent times seems very close to a breaking point. We are in fact talking about a “strange” sugar , often recommended in the presence of diabetes due to its low glycemic index (19-23).
Disadvantages of Fructose
Why Diabetics should avoid excess fructose
The characteristics listed so far seem to celebrate a lucky and lasting marriage between fructose and diabetes. Unfortunately, however, analyzing the metabolism of this sugar we realize that at high doses the ratio seriously tilts up to an almost definitive break. Data in hand, in fact, several studies show that HIGH fructose intakes (> 40-60 grams per day in addition to that already present in fruit and honey ) lead to rather negative metabolic consequences:
- fructose has about seven times the ability to form advanced glycation products ( AGEs ) than glucose (excess sugars bind to certain groups of proteins , forming these tissue-damaging advanced glycation products);
- fructose does not suppress ghrelin (a gastric hormone that stimulates appetite);
- chronic exposure to fructose favors the onset of metabolic syndrome ;
- a diet particularly rich in fructose increases insulin resistance ; in fact, although this sugar does not directly increase insulin secretion , it does so indirectly, hindering the hepatic metabolism of glucose and its transformation into glycogen (the form in which the liver deposits glucose);
- fructose increases lipogenesis de novo, and the synthesis of triglycerides and fatty acids ; in essence, therefore, despite being a carbohydrate , fructose is metabolised as a fat and is associated with an increase in triglycerides .
For all these reasons, it has been shown that chronic exposure to high levels of fructose favors the onset of:
- hypertension (by inhibition of nitric oxide ); myocardial infarction ; dyslipidemia ; pancreatitis (secondary to hypertriglyceridemia ); obesity ; liver dysfunction ( steatosis ); insulin resistance; hyperuricemia , gout (increased uric acid synthesis ), habituation , if not outright dependence .
These effects have mostly been demonstrated in laboratory animals, and do not appear to be related to the effect of additional calories induced by fructose supplementation, since all these negative consequences have not been recorded following diets equally rich in glucose and starch . Although the effects of fructose in the human body are still to be clarified, these studies certainly cannot be ignored.
As if that weren’t enough, the intensive use of fructose in drinks and many products, in the form of corn syrup and the like , has been linked to the increase in obesity recorded in recent decades. The biggest bogeyman, however, derives from the ability of fructose to increase triglyceridemia, with a consequent increase in cardiovascular risk .
For the above, the US association “The American Diabetes Association” states that the use of added fructose to sweeten foods is inadvisable in the presence of diabetes, but there is no reason to also avoid the amount of fructose naturally present in foods such as fruit, honey and vegetables.
