Fruits and other foods rich in fructose do not seem to have any harmful effects on blood glucose levels; however, sugary beverages and some other foods that add excess "low energy" energy to nutrition can have a detrimental effect.
"These findings can help to reorient nutritional recommendations for fructose to prevent and treat diabetes," said John Sienvenpiper, lead author of the study and clinical food expert at St. Michael's Hospital in Toronto, Canada. ,
The role of sugars in the development of diabetes and heart disease raises a wide debate and there is increasing evidence that fructose can be particularly harmful to health.
Fructose is produced naturally in a variety of foods – raw fruits and vegetables, natural fruit juices and honey.
It is also added to foods such as soft drinks, snacks, processed products, sweets and desserts that we consume as "free sugars".
Dietary guidelines recommend reducing free sugars, especially fructose in sweetened beverages, but it is not clear whether for all food sources of these sugars.
Researchers have analyzed the results of 155 studies that evaluated the effect of various dietary sources of fructose sugars on blood sugar levels in people with and without diabetes observed over 12 weeks.
The results show that most foods containing fructose sugars have no detrimental effect on blood sugar levels when these foods do not provide extra calories.
When analyzing specific foods, fruit and fruit juices, when these foods do not provide excess calories, can have a beneficial effect on blood sugar and insulin control, especially in people with diabetes, while foods that add surplus "poor nutrients" to food, especially sugar beverages and fruit juices, appear to have harmful effects.
Researchers conclude: "Until more information is obtained, healthcare professionals should be aware that the harmful effects of fructose sugars on blood glucose appear to be mediated by energy and the source of food."