April 19, 2015
Alzheimer's Disease – Part 1
Alzheimer's disease and diabetes do have a link. The Mayo Clinic recognizes this, as do a few other organizations. A few organizations reject the link and more state that the link is in question and acknowledge that the evidence is conflicted. New research suggests that those with insulin resistance or diabetes are at significantly higher risk of developing one of today's most devastating and incurable neurological disorders: Alzheimer's disease.
The connection between diabetes and Alzheimer's is yet another compelling reason for those who value their health to address issues of impaired insulin sensitivity before it is too late. Although diabetes is an epidemic, it is also preventable and reversible through strategies that incorporate dietary changes, lifestyle modifications, and nutritional supplementation.
Alzheimer's cost the US $130 billion in 2011 alone. One of the biggest risk factors is having type 2 diabetes. This kind of diabetes occurs when liver, muscle, and fat cells stop responding efficiently to insulin, the hormone that tells them to absorb glucose from the blood. The illness is usually triggered by eating too many sugary and high-fat foods that cause insulin to spike, desensitising cells to its presence. As well as causing obesity, insulin resistance can also lead to cognitive problems such as memory loss and confusion.
While medical researchers have yet to pinpoint a single cause of Alzheimer's disease, they have uncovered some of the basic biochemical processes that underlie the hallmark mental changes seen in Alzheimer's.
First, Alzheimer's sufferers exhibit a marked decline in levels of acetylcholine, a neurotransmitter (that is, a chemical messenger of the nervous system) that is vitally important to memory formation and retention in certain regions of the brain. Second, Alzheimer's patients demonstrate an accumulation of harmful beta amyloid deposits, or senile plaques, in the brain. Third, brain autopsies of Alzheimer's patients show signs of significant oxidative damage induced by free radicals. Finally, new research indicates that advanced glycation end products may also initiate this dreaded condition.
Feeding animals (in this case rats) a diet designed to give them type 2 diabetes leaves their brains riddled with insoluble plaques of a protein called beta-amyloid, one of the calling cards of Alzheimer's. We also know that insulin plays a key role in memory. Taken together, the findings suggest that Alzheimer's might be caused by a type of brain diabetes. If that is the case, the memory problems that often accompany type 2 diabetes may in fact be early-stage Alzheimer's rather than mere cognitive decline.
While declining levels of acetylcholine and formation of beta amyloid plaques in the brain are characteristic of Alzheimer's, oxidative damage and the accumulation of advanced glycation end products occur in both Alzheimer's disease and diabetes. These biochemical similarities may be a telling link between the two seemingly different diseases.
Scientists from Kaiser Permanente in Oakland, CA, reported that diabetic individuals with very poor blood glucose control experienced a dramatically increased risk of dementia and Alzheimer's. Their eight-year study, which tracked 22,852 patients, aged 50 or above with type II diabetes, sought to determine whether elevated glycosylated hemoglobin, a marker of long-term blood glucose control, correlated with an increased risk of dementia. They found that patients with very poor blood glucose control were more likely to develop dementia.
Researchers from the Mount Sinai School of Medicine in New York City discussed the link between diabetes-related toxins and impaired memory function. Advanced glycation end products (AGEs) are increased in people with diabetes, as well as in those with cardiovascular and kidney disease. They are also found in the brains of people with Alzheimer's, and laboratory findings suggest that AGEs may contribute to the formation of Alzheimer's plaques and tangles. The researchers evaluated nearly 200 cognitively healthy people aged 70 or older using tests of memory and thinking ability, and measured AGE levels in their blood. They found that those with the highest AGE levels fared significantly worse on six different tests than those with low AGE levels. This relationship could not be explained by factors such as gender, educational level, heart disease, or related conditions such as high blood pressure. The researchers concluded that dietary and lifestyle interventions to decrease advanced glycation end products in the blood deserve further study for preventing or delaying Alzheimer's disease.
Most of recent research points to a link between diabetes and Alzheimer's Disease. How firm this link is still is in doubt, but more evidence is now in the affirmative.