I eat fruit juice blended by blender every night. I use a blender to blend Watermelon, Lychee, Melon etc. Is the sugar from the fruit a risk for diabetes?
The question is about whole fruits vs blended fruits (smoothies), but I haven't found any studies about smoothies, so I included those about fruit juices. Both the smoothies and the fruit juices are liquid, so they pass the stomach faster than whole fruits, which can result in higher blood glucose spikes (a possible risk factor for diabetes). The other aspect is that smoothies probably contain about the same amount of fiber than whole fruits, while fruit juices contain much less fiber. Fiber likely decreases blood glucose spikes after meals.
Concluding from academic.oup.com, blending fruits probably does not affect the fiber in the nutritional sense:
The quantitative measurement of dietary fiber does not recognize its diverse actions on nutrient absorption...
According to 2 systematic reviews of studies, intake of 100% fruit juice (no sugar added) is not associated with diabetes type 2.
A higher intake of sugar-sweetened fruit juice was significantly associated with risk of type 2 diabetes, while intake of 100% fruit juice was not associated with risk of developing type 2 diabetes.
Overall, findings from this meta-analysis of RCT suggest a neutral effect of 100 % fruit juice on glycaemic control. These findings are consistent with findings from some observational studies suggesting that consumption of 100 % fruit juice is not associated with increased risk of diabetes.
However, according to one 2015 systematic review:
both artificially sweetened beverages and fruit juice were unlikely to be healthy alternatives to sugar sweetened beverages for the prevention of type 2 diabetes.
And finally, according to one study, which followed nurses for 18 years: Intake of Fruit, Vegetables, and Fruit Juices and Risk of Diabetes in Women (PubMed, 2008):
Consumption of green leafy vegetables and fruit was associated with a lower hazard of diabetes, whereas consumption of fruit juices may be associated with an increased hazard among women.
Fruit fibres help regulate sugar blood level .
Thank to this, if you do not just extract juice from your blender but you drink/eat to whole processed fruit, I think that will not be an issue for diabetes, or better, it has the same value of eating the same entire fruit.
What I don't know:
- does mastication play a role in this game?
- does blender break fibres? if yes, how them compare to the whole ones?
EDIT: linked answer Is it better to eat fruit as they are, than to have them in liquid form?