‘Don’t exclude berries because of sugar content’, say Scandinavian researchers

Sweetened berries in a healthy diet should not be excluded from a healthy diet since the fiber and polyphenols in the fruit null the glycemic effect, says a new study from Finland.

Data from a study with healthy people revealed that supplementing meals with sweetened lingonberry powder did not produce a higher glycemic response despite the overall meal having significantly more sugar.

“The results of this study indicate that the fibers and/or polyphenols present in lingonberries null the glycemic effect of the sugars that originate from the berries when consumed together with added sugar,” report researchers from the University of Turku in Nutrition Research.

“It can thus be argued that berries should not be excluded from healthy diets despite their sugar content.”

The new study is said to be the first to test the effects of fibers and polyphenols in lingonberries in human subjects, with a specific focus on how lingonberry powder affects blood sugar and blood lipid levels after a high sugar or high fat meal.

Ten people took part in the high sugar experiment, while 13 participated in the high-fat study. Test meals consisted of fat-free yoghurt formulated with either glucose (50 g) or triacylglycerols (35 g) with or without lingonberry powder (40 g for the the glycemia trial and 60 g in the lipemia trial).

Results showed that, despite the lingonberry glucose-yogurt having more sugars than the control yogurt (64.7 grams versus 50 grams, respectively), there were no significant differences in blood sugar levels after the meal.

On the other hand, no lipid-lowering effects were observed in the high-fat meal, said the researchers.

“This seems to indicate that the sugars of the lingonberry powder were compensated by a glycemia-lowering effect of fibers and/or polyphenols. Furthermore, the insulin response, although insignificant, supports the effect seen in the glycemic response because it points to an attenuating effect of the lingonberry.”

Source: Nutrition Research

Published online ahead of print, doi: 10.1016/j.nutres.2012.06.004

“The fiber and/or polyphenols present in lingonberries null the glycemic effect of the sugars present in the berries when consumed together with added glucose in healthy human volunteers”

Authors: K.M. Linderborg, R. Jarvinen, H-M. Lehtonen, M. Viitanen, H.P.T. Kallio