The risk of Alzheimer’s disease is increased in people with diabetes, who are “resistant” to the effects of insulin and therefore develop high blood glucose levels.
New research suggests that a decreased level of an enzyme that breaks down insulin — insulin-degrading enzyme (IDE) — in brain tissue is the missing link between the two disorders, according to Dr. Greg M. Cole’s research at the University of California, Los Angeles.
Moreover, since insulin’s action in the brain increase IDE levels, it may be possible to prevent or even reverse Alzheimer’s disease by boosting insulin activity.
Cole’s group found in lab-dish experiments with brain neurons that insulin significantly increased IDE levels.
Comparing brain specimens obtained from normal patients and those with Alzheimer’s disease, IDE was decreased in the Alzheimer’s tissue, the researchers report the Journal of Neuroscience.
And in mice bred to develop a condition similar to Alzheimer’s disease, a diet high in safflower oil led to significantly reduced levels of IDE and more of the amyloid beta plaques associated with the disease.
There are a number of approaches that may increase IDE levels and thus reduce amyloid beta in the brain, Cole noted. For example, the anti-diabetes drug Avandia "an agent used to treat insulin resistance, is currently being tested in a clinical trial to see if it can help patients with Alzheimer’s disease," he said.
But even lifestyle changes — increasing exercise, lowering saturated fats in the diet, and increasing dietary fish oil, which is rich in omega-3 polyunsaturated fatty acids — can modify insulin’s effects and perhaps "increase the degradation and clearance of amyloid beta," Cole concluded.
Journal of Neuroscience, December 8, 2004
FACT: Are Ace inhibitors recommended for All those with coronary artery disease? NO.
There is new controversy about whether Ace inhibitors are beneficial for patients with STABLE coronary artery disease. Current guidelines recommend ACE inhibitors for almost ALL patients with coronary disease. This is based on several trials that show these drugs reduce mortality in many patients with heart disease. But now a large study shows that Ace inhibitors don’t provide any extra benefit in LOW-risk patients. These are patients who are well-controlled on aspirin, a statin, and a beta-blocker. Keep in mind that ACE inhibitors are still beneficial for higher-risk patients. These are patients who have high blood pressure or cholesterol despite treatment. Or those with other cardiac risk factors as diabetes, heart failure, or recent heart attack.
Ann Intern Med 2004;141:562-7. J Am Coll Cardiol 2001;38:1581-3.