Strength Conditioning and Nutrition 101

Brain Health

Written By Martin Ng

According to Yahoo News, one recent article suggested that sugar can make you dumb; however, is this really the case?  In the study, rats were fed with omega-3 fatty acid diet (n-3 diet) with and without fructose; another group that was n-3 deficient was fed with and without fructose as well.  It was found that high levels of fructose were associated with cognitive dysfunction.



Table of Contents

• Background
• Research
• Summary
• Reference

Background
It should be clarified that the rats were fed with fructose solution and that though fructose is a “sugar”, it is different from other sugars such as glucose.  This makes a huge difference since their metabolic pathways are different and thus have different effects.  Dietary fructose is eventually converted to triglycerides in its metabolic pathway; however, the brain cannot use triglycerides as an energy source directly.  Triglycerides must first undergo lipolysis producing fatty acids and glycerol.  The glycerol then enters the glucogenesis pathway to produce glucose-6-phosphate which can be used as an energy source for the brain; the fatty acids undergo beta oxidation producing acidic ketone bodies.  One suffers from diabetic ketoacidosis (DKA) when these ketone bodies build up due to insufficient insulin levels.

Research
The experiment described by Yahoo! News found in The Journal of Physiology shows a positive correlation between serum triglyceride levels and insulin resistance and also triglyceride levels with memory functions.  This suggests that memory functions may be dependent on insulin resistance.  Furthermore, n-3 diet contributed to metabolic homeostatsis; dietary docosahexaenoic acid (DHA) helps maintain proper insulin brain signaling.  Additionally, a recent study in Neuroscience Letters shows that cognitive dysfunction was found to be associated with DKA.

Summary
Sugar includes many carbohydrates such as fructose and glucose.  Eating ONLY FRUCTOSE ALONE may make you “dumber”.  The study shown in Yahoo! News by The Journal of Physiology uses only fructose as an energy source causing insulin resistance (DHA, an n-3 fatty acid helps maintain homeostatsis) and most likely a build up of ketone bodies as well due to insufficient levels of glucose causing DKA.
Furthermore, a recent study found in Neuroscience Letters shows that there is an association between cognitive dysfunction and DKA supporting my hypothesis that fructose causing cognitive dysfunction is a result of DKA

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Agrawal, R. and F. Gomez-Pinilla. 2012. ‘Metabolic syndrome’ in the brain: deficiency in omega-3 fatty acid exacerbates dysfunctions in insulin receptor signalling and cognition. J Physiol 590 (10): 2485-2499

Glaser, N.; S. Andersonb; W. Leongb; D. Tancredia and M. O’Donnell. 2012. Cognitive dysfunction associated with diabetic ketoacidosis in rats. Neuroscience Letters 510: 110-114