Intranasal insulin improves memory in humans

[Genecks]

I'm reading an article, I don't know if some of you can get access to it, but I'd like to know what some of the scientists here think about it.

 

Personally, I think the results are bogus and insignificant. I think over the 8 weeks that people just got better at doing certain tasks, because people get better over time at doing certain tasks. The brain starts forming to do those things better. If I'm understanding the statistics right, there isn't a large difference between the placebo group and the treatment group. There was an enhanced self-confidence effect from the insulin, though. I'm not sure what psychological consequences that would lead to, though. I haven't the slightest clue.

 

---------------------------------------------------------

Psychoneuroendocrinology

Volume 29, Issue 10, November 2004, Pages 1326-1334

 

Intranasal insulin improves memory in humans

 

authors:

Christian Benedicta,*, Manfred Hallschmida, Astrid Hatkea,

Bernd Schultesb, Horst L. Fehmb, Jan Borna, Werner Kernb

 

Abstract:

Previous studies have suggested an acutely improving effect of insulin on memory function. To study changes in memory associated with a prolonged increase in brain insulin activity in humans, here we used the intranasal route of insulin administration known to provide direct access of the substance to the cerebrospinal fluid compartment. Based on previous results indicating a prevalence of insulin receptors in limbic and hippocampal regions as well as improvements in memory with systemic insulin administration, we expected that intranasal administration of insulin improves primarily hippocampus dependent declaration memory function. Also, improvements in mood were expected. We investigated the effects of 8 weeks of intranasal administration of insulin (human regular insulin 4 x 40 IU/d) on declarative memory (immediate and delayed recall of word lists), attention (Stroop test), and mood in 38 healthy subjects (24 males) in a double blind, between-subject comparison. Blood glucose and plasma insulin levels did not differ between the placebo and insulin conditions. Delayed recall of words significantly improved after 8 weeks of intranasal insulin administration (words recalled, Placebo 2.92 +/- 1.00, Insulin 6.20 +/- 1.03, p < 0.05). Moreover, subjects after insulin reported signs of enhanced mood, such as reduced anger (p < 0.02) and enhanced self-confidence (p < 0.03). Results indicate a direct action of prolonged intranasal administration of insulin on brain functions, improving memory and mood in the absence of systemic side effects. These findings could be of relevance for the treatment of patients with memory disorders like in Alzheimer's disease.

Edited April 4, 2010 by Genecks

[Mr Skeptic]

Hm, it would make some sense for the brain to consider insulin a "reward chemical" of some kind. Increased insulin generally means you ate a good meal, and you should remember what you did to get it. No?