You probably remember (or maybe you don’t) the hilarious scenes from Arrested Development in which GOB tried to use forget-me-not pills on his brother Michael & of course on himself! You can reminisce here.
Interestingly, new research suggests that this scene could have played out with GOB trying to shove some standard american diet (SAD) (foods containing higher amounts of fructose in particular) into Michael’s mouth.
There’s been a lot of excellent research surfacing since Dr. Perlmutter published Grain Brain (here) back in Sept of 2013. Most of it has reinforced the fact that as humans, we in the
Western world are eating far too much refined carbohydrates (i.e. sugar & grains) and it’s become clear that this trending increase along with a change from traditional fats to more processed vegetable oils as well as a decrease in overall fat content and these changes have occurred much more rapidly over the last 60 years or so. This could definitely be at least partly responsible for the metabolic disturbances of the body & the MIND that we are facing in higher amounts than ever before in history.
The reason for this tirade, is that a recent study (subscription required) from the University of Southern California and published in the journal Hippocampus looked at the effects of refined carbohydrates and in particular sucrose & high fructose corn syrup (HFCS) on spatial memory function and neuro-inflammation in adolescent rats.
The authors used the standard rat diet and either an 11% sucrose solution, 11% HFCS solution or and extra bottle of water (Control). They did this in both adult and adolescent rats. In adolescent rats the HFCS solution imparied hippocampal-dependent spatial learning & memory in a maze, with moderate learning impairment also observed for the sucrose group.
They found no effect of the solutions on anxiety in the zero maze or performance in non-spatial response learning tasks. They did observe increases in pro-inflammatory cytokines ((Interleukin) IL-6, IL-1B) in the dorsal hippocampus for the adolescent HFCS group relative to controls, whereas liver IL-1B and plasma insulin levels were elevated for both adolescent-exposed sugar groups. Intake of HFCS or sucrose in adults did NOT impact spatial learning, glucose tolerance, anxiety or neuro-inflammatory markers. The authors conclude that consumption of added sugars, particularly HFCS, negatively impacts hippocampal function, metabolic outcomes & neuroinflammation when consumed in excess during adolescent period of development.
This study is relatively well done & thorough. Obviously, it’s unethical to do this sort of research in humans, so the rat model does allows for much more mechanistic data generation. An interesting follow up study might be serial brain scans in adolescents who are known to consume high amounts of HFCS and examine morphological effects on brain development regional activity. This might show how translatable this data is to humans.
It could help explain why we’re seeing lower test scores in North American children/adolescents over the last few decades compared with international peers (here), which coincides with a steady increase in refined carbs (sugar & grains) and concomitantly and of equal or possibly greater importance a decrease in fat intake. This could then lead us to what I would consider a great intervention trial in North American kids (& adolescents & adults as well), which would entail the abandonment of the low fat, high carb (highly refined carb) diet & return to a more traditional, evolutionary-based nutrition strategy involving lower (& unrefined) carbohydrates, higher fat and moderate protein intake (i.e. paleo, primal or at least no sugar/no grains). I’ve discussed my theories on this in a couple of prior posts including the potential metabolic consequences of highly refined carb (grain)-based diet (here) and the impact of low whole vegetable & fruit intake (natural carb sources) could have on mental health (here). It’s no mystery that fat intake is associated with brain development and in particular the omega-3s and this link has been demonstrated early on in development in breast milk fatty acid content (here).
Anyway, it’s all part of the puzzle & slowly we will put it all together. Definitely no one will be hurt by dropping the highly refined carbs from their diet – it’s NOT easy, but I think it’s definitely worth it, because if nothing else it should help break the cycle of addiction that most of us feel when consume hyper-palatable foods, almost all of which are made from highly refined carbs.
Happy Thanksgiving to our fellow Canadians and Happy Columbus day to many of our American friends! Have a great weekend!
Till next time! Enjoy life in Health & Fitness but enjoy it none-the-less!
Graph on Sugar intake over last century (here).