The Effect of Long-Term Taurine Supplementation and Fructose Feeding on Glucose and Lipid Homeostasis in Wistar Rats - Advances in Experimental Medicine and Biology - page 45

Tappy et al. 2010 ). However, several human and animal studies have found none or
only a small effect of a fructose diet on glucose metabolism (Abdullah et al. 2009 ;
Tappy and Lê 2010 ). Thus, in some rat strains, long-term high-fructose diets cause
an adaptation to the diet, completely abolishing the effect of a high-fructose diet on
glucose and lipid homeostasis and glucose tolerance (Stark et al. 2000 ) . Furthermore,
fructose effects may depend on the composition of the control diet, i.e., effects of
fructose have been reported to be significant only when compared to chow but not
if compared to a diet with fructose substituted by starch (Kim et al. 1999 ) .
An increase in fasting blood glucose has been linked to overall mortality and
development of metabolic and cardiovascular disease (Seshasai et al. 2011 ; Singh
et al. 2010 ). The results of the current study are particularly worrying, as taurine is
an often used ingredient in energy drinks, and thereby automatically consumed
together with a large amount of fructose (from either sucrose or high-fructose corn
syrup used as sweeteners). There is a good case from epidemiological studies for
fructose ingestion as a precipitator of insulin resistance albeit age, obesity, study
duration, and other dietary factors are possible confounding factors (Stanhope
2012 ). Thus, the exact circumstances in which increased fructose consumption may
be detrimental in humans are currently not well established. However, this study
points towards a possible link between glucose homeostasis and a combined intake
of fructose and taurine. As such further studies are needed to examine this interac-
tion between taurine and fructose.

5.5 Conclusion

In summary, the current study indicates that long-term taurine supplementation may
be beneficial with regard to glucose tolerance when given together with fructose.
However, taurine also increases fasting glucose when given together with fructose.
Thus, this study did not corroborate earlier findings showing that taurine has a solely
beneficial effect on glucose and lipid homeostasis. Despite these negative findings,
when taking into account earlier studies and the current study, it seems quite clear that
there is a connection between taurine and glucose homeostasis and possibly a connec-
tion to dietary fructose, but also that a number of unanswered questions remain.

Acknowledgements This research was supported by The Danish Strategic Research Council grant
#09-067124 and #09-059921, Danish Medical Research Council grant #271-07-0732, by Købmand
i Odense Johann og Hanne Weimann f. Seedorffs Legat, Gangstedfonden, Ernst Fischers mindele-
gat, Eva og Hans Carl Adolfs Mindelegat, and Direktør Emil Hertz og Hustru Inger Hertz Fond.

References

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