Brain Health and Blood Sugar

Is Alzheimer's the New Type 3 Diabetes?

By VRP Staff

In the past, Alzheimer’s disease and diabetes were considered two unrelated conditions. However, scientists are discovering alarming similarities between type 2 diabetes and cognitive decline, adding dementia to the list of major concerns diabetics already face, including heart disease, strokes, kidney failure, and blindness.

Several large studies have found that people with type 2 diabetes are twice as likely to develop Alzheimer’s compared with healthy people of the same age and sex.1-2 Even more worrisome is that people with borderline diabetes, which affects a large part of the US population, are also at risk. A recent study found that 70 percent of elderly people with chronically elevated levels of blood glucose were more likely than those with normal levels to develop Alzheimer’s.³

The researchers concluded, “our findings highlight the need to detect borderline diabetes in order to proactively address both type 2 diabetes and dementia.”³

Scientists have also discovered that once Alzheimer’s is diagnosed, people with type 2 diabetes are twice as likely to die sooner than those without diabetes.⁴ As evidence for a link between the two diseases continues to mount, researchers are uncovering a number of reasons to explain the possible connection.

Poor Insulin and Glucose Control

Insulin resistance is a hallmark of type 2 diabetes and occurs when the body cannot properly use insulin, the hormone that is secreted by the pancreas to move glucose from the blood into cells that need it. In people on their way to type 2 diabetes, the pancreas produces extra insulin in a futile attempt to compensate. However, this only leads to higher insulin and glucose levels in the blood and a deficiency of glucose in the cells that need sugar to function properly, particularly brain cells, setting the stage for the development of Alzheimer’s. Scientists also believe that diabetes impacts memory via another mechanism: by increasing the risk blood vessels will become obstructed, restricting blood flow to the brain.

In addition, the recent discovery that insulin receptors are expressed in the hippocampus of the brain, which is crucial for learning and memory formation, has added further weight to the link with diabetes. When insulin becomes less able to bind to its receptors in the brain, the mechanisms for nerve-cell survival and memory formation also become affected, increasing the risk for Alzheimer’s.⁵

Toxic Byproducts of Excess Glucose

High blood glucose levels also impact cognition through the formation of sugar-related toxins called advanced glycation end products (AGEs). Anyone who has made toast has witnessed glycation firsthand, as reactions between sugars and proteins in the bread cause it to turn brown when heated. Similarly, in the body, glycotoxins are formed when sugars interact with proteins and lipids, damaging the structure of proteins and membranes, rendering them less able to carry out their many vital processes. These toxic AGE molecules are a critically important factor linking aging, diabetes, and Alzheimer’s.

In diabetes, AGEs play a pathologic role in damaging blood vessels and contribute to the micro- and macrovascular complications of the disease. They also contribute to degenerative processes in the brain. Laboratory studies show that AGEs are a key factor involved in the cross-linking of harmful beta-amyloid plaques in the brain that are implicated in Alzheimer’s.⁶

AGEs have also been found to accumulate in brain regions associated with memory and attention, areas also affected in Alzheimer’s.⁷ A recent study in approximately 200 healthy people aged over 70 found that those with the highest AGE levels performed significantly worse on six different tests of memory and cognitive ability than those with low levels.⁸

Promoting Healthy Blood Glucose Metabolism

Even those who pay careful attention to what they eat may find their blood glucose levels increase with age. Fortunately, combating high blood glucose levels and insulin resistance will help to maintain cognitive health. In addition to exercise and avoiding high-glycemic foods, certain natural substances may help maintain healthy blood glucose levels and prevent insulin spikes as well as quell the damage wrought by glycation.

N-Acetyl cysteine (NAC): A precursor of the tripeptide antioxidant glutathione, NAC protects pancreatic insulin-producing cells against damage from free radicals, which flourish in the presence of high glucose levels. NAC also inhibits the activation of a key proinflammatory molecule called nuclear factor-kappa beta.⁹ In addition, animal studies show that NAC inhibits the blood glucose surge and weight gain that occurs after consuming a sucrose-rich diet,¹⁰ while also protecting against oxidative stress, a major factor in diabetic complications.

Vitamin C: According to a large study of nearly 6,500 people aged 45-74 years, a vitamin C deficiency increased HbA1c, a measure of long-term blood sugar control that indicates how much glycation is occurring in the body. This study found that plasma vitamin C levels were significantly higher in subjects with HbA1c less than 7 percent compared with those whose HbA1c levels were 7 percent or more. The researchers concluded, “dietary measures to increase plasma vitamin C may be an important health strategy for reducing the prevalence of diabetes.”¹¹

Human studies have demonstrated that vitamin C supplements may help lower blood glucose levels in diabetics. Vitamin C may also produce additional reductions in low-density lipoprotein (LDL) and plasma free radicals.¹² A recent study of nearly 22,000 non-diabetic patients found that those whose plasma vitamin C levels were in the top 20 percent had a 62 percent lower risk of developing diabetes than those in the lowest fifth.¹³ Vitamin C also inhibits sorbitol accumulation and glycation of proteins that cause diabetic complications.

Vitamin E: An antioxidant that modulates insulin action and improves glucose transport,¹⁴ vitamin E is important in reducing long-term diabetic complications. Studies also have shown that diets rich in vitamin E significantly decrease the rate of mental decline and may help lower Alzheimer’s risk in some people.¹⁵ An effective approach is to combine vitamins C and E, which provides more complete protection against molecular damage.¹⁵

Goat’s Rue: This natural extract is rich in aminoguanidine, which helps to maintain healthy blood glucose levels. Goat’s rue improves insulin sensitivity and stabilizes blood sugar in both normal and diabetic humans¹⁶ as well as exerts anti-AGE effects.

Cinnamon: In a recent trial, cinnamon was found to help diminish the blood glucose spike that typically follows a meal, partly by delaying gastric emptying.¹⁷ In another study, daily consumption of 1-6 grams of the spice for 40 days reduced fasting serum glucose levels by 18-29 percent in people with type 2 diabetes.¹⁸ It is believed that cinnamon’s water-soluble polyphenols are responsible for its metabolic effects. Research shows that these natural compounds upregulate the expression of genes involved in activating insulin receptors on the cell membranes, increasing cellular glucose uptake and lowering blood glucose levels.¹⁹

Quercetin: This bioflavonoid strongly inhibits aldose reductase, an enzyme that converts glucose into sorbitol, which is implicated in diabetic complications. Quercetin also protects insulin-producing cells in the pancreas by blocking the genetic expression of cytokines and enzymes that are important mediators of inflammatory responses.²⁰

Vanadium: Vanadyl sulfate is a trace mineral that functions as an insulin-mimetic, improving glucose tolerance in type 2 diabetics and decreasing insulin requirements.²¹ A study of vanadyl sulfate treatment in type 2 diabetes found that a daily 150-mg dose for six weeks reduced blood glucose and HbA1c, while improving performance during an oral glucose tolerance test, which measures the body’s ability to metabolize glucose.²²

Bitter melon: This tropical fruit lowers blood glucose without raising insulin levels. In one study, an extract from bitter melon significantly improved glucose tolerance in 73 percent of 18 patients with type 2 diabetes.²³
Combining a supplement that contains all of the above ingredients (such as GluControl™) with a chromium supplement can be an ideal way to support healthy blood sugar levels and cognitive health.

AGE-Blocking Nutrients

Carnosine: This dipeptide comprised of beta-alanine and histidine binds to other protein molecules in the body, shielding them against glycation. Carnosine also protects neuronal cells from many of the pathologies implicated in Alzheimer’s disease, such as amyloid-beta peptide toxicity²⁴ and lipid peroxidation of neuronal membranes in the brain.²⁵

Vitamin B1 (thiamine) and benfotiamine: Benfotiamine is the highly bioavailable form of vitamin B1 that prevents nerve and blood vessel damage caused by glycation processes in diabetes. It works by blocking the accumulation of glycotoxins before they can do damage. Recent studies have shown that benfotiamine may reduce the threat of diabetic complications by suppressing the effects of AGEs²⁶ and significantly improving neuropathy scores in those with painful peripheral neuropathy.²⁷

Vitamin B6: Pyridoxine (vitamin B6) is converted to several active metabolites in the body, such as pyridoxamine and pyridoxal-5-phosphate, which react with key intermediates involved in glycation and suppress the formation of AGEs. Pyridoxamine has also been shown in human studies to help avert diabetic complications.²⁸

NAC: is also a natural potent AGE inhibitor shown to reduce lipid peroxidation in neuronal cell lines after AGE exposure. These impressive findings have led researchers to conclude that NAC could be useful in protecting brain tissue from the pathophysiological consequences characteristic of Alzheimer’s.²⁹

Two other emerging, powerful AGE-blocking agents are Guava and Yerba maté. Abundant polyphenols found in both of these plant extracts are believed to be responsible for their significant and dose-dependent inhibitory effect on the glycation of lipids and proteins.^30-31
Using a supplement that combines each of these ingredients (such as AGEBlock®) can play an important role in inhibiting AGEs and thus enhancing cognitive health.

Conclusion

Diabetes and Alzheimer’s are two epidemic disorders that share an extraordinary number of biochemical similarities; each disease is poised to threaten the health of tens of millions of Americans. Even people who watch what they eat may experience accumulated damage from glycation in tissues exposed to normal blood sugar for a long enough time. Fortunately, an integrated program comprising an anti-glycation eating plan, exercise, and scientifically validated nutrients combats several insidious factors that can help ward off the related afflictions of diabetes and Alzheimer’s.

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