Alzheimer’s dementia (AD) is a progressive disorder with no identifiable cause or effective treatment. All the drug treatments available today appear to have major side effects and the cognitive improvement is only marginal.
Now there is a study showing that intranasal insulin spray may be of benefit in patients with Alzheimer’s dementia. The latest study done by Suzanne Craft, PhD, from the Veterans Affairs Puget Sound Health Care System in Seattle, reveals that individuals who received 20 IU of intranasal insulin daily for four months had improvement in their cognition and overall function (1).
The researchers indicate that insulin is critical for normal brain function and alteration in its metabolism may be a contributing factor to the development of Alzheimer's disease. The researchers mention that because some patients with AD have lower levels of insulin in the brain, perhaps delivering supplemental can help improve cognition.
The present study showed that both the 20 and 40 IU of insulin led to preservation of function in carrying out daily living activities in AD patients. This improvement was not seen in patients with milder symptoms. In additon, the researchers found no change in the AD biomarkers like tau protein.
More importantly, a few patients also underwent PET assessment after completion of the study. The imaging studies revealed less dementia-related hypometabolism in several areas of the brain in patients receiving insulin. In this study no serious adverse reactions were noted.
Similar studies in animals have also shown that insulin may be acting via receptors in the frontal cortex (2).
So what does this mean for the consumer?
While these results may sound impressive they are fraught with errors. To date, there is no imaging technique that can reliably make a diagnosis of Alzheimer's dementia.
Moreover, there is no reliable way to measure insulin levels in the brain, asides from autopsy specimens. To claim that AD patients have low levels of insulin is false, because there is no scientific evidence for this statement that I have read.
In my opinion the study is not bona fide at all. First off all, if insulin was a cure for Alzheimer's dementia, then most type 1 diabetic patients would never develop this disorder since, they are treated with insulin for life. Clearly this is not the case.
Secondly, if insulin deficiency was a cause of Alzheimer's dementia, only type 1 and type 2 diabetics would develop Alzheimer's dementia. Again, this is not the case.
Thirdly, administering insulin to a non-diabetic patient is very risky. Hypoglycemia is a serious complication of insulin therapy and can be fatal if not recognized.
To date, there is no evidence to show that diabetics (who lack insulin) have a higher prevalence of Alzheimer's dementia than non-diabetics. More studies are needed before insulin can be recommended for treatment of any other medical disorder, besides diabetes.
Finally, the healthcare professional who prescribes insulin to non-diabetics better have good medical malpratice insurance.
Sources
1. Craft S, et al "Intranasal insulin therapy for Alzheimer disease an amnestic mild cognitive impairment: a pilot clinical trial" Arch Neurol 2011
Abstract: http://www.ncbi.nlm.nih.gov/pubmed/21911655
2. Chen S et al. Amelioration of neurodegenerative changes in cellular and rat models of diabetes-related Alzheimer's disease by exendin-4. Age (Dordr). 2011 Sep 8. Abstract: http://www.ncbi.nlm.nih.gov/pubmed/21901364
Reviewed September 21, 2011
by Michele Blacksberg RN