Cut Diabetes Risk to Prevent Alzheimer’s?

Cut Diabetes Risk to Prevent Alzheimer's? (by BrainReady special guest contributor Dr. Susan Parsons, MD)

In my last article for BrainReady ("Avoid the Dreaded 'D'"), I discussed the nature of both Alzheimer’s and vascular dementia.  I explained the disabling symptoms, the underlying pathology, and some of the risk factors associated with these diseases.

The bad news about Alzheimer’s disease?  Genetics and age increase your risk.  Obviously you can’t change your genes or the passage of time.

The good news?   You can cut your risk of dementia by following my healthy lifestyle recommendations.  A little prevention goes a long way toward minimizing the risk of developing these disorders as we age. 

Controlling Our Risk for Alzheimer’s Disease

Number one on my list of modifiable risk factors?  Diabetes.  Even if you only have obesity or pre-diabetes, you most likely have insulin resistance, a condition which appears to be a contributor to the pathology of Alzheimer’s dementia. 

More and more evidence accumulates to support the Diabetes-Alzheimer’s link.  My own clinical observations support this relationship as well.  Many, although not all, of my elderly diabetic patients have dementia. 

The Diabetes – Alzheimer’s Connection

Let’s look at some of the evidence.  A 2004 study from Rush University Medical Center in Chicago monitored 843 Catholic nuns, brothers, and priests, all who were over age 55 at the beginning of the study.  The findings?  Those with Type 2 Diabetes were much more likely to develop Alzheimer’s disease by the end of the 9-year study.  In fact, the presence of diabetes increased the risk of Alzheimer’s by 65%. 

Very similar results were found in a 2007 Swedish study.  Elderly subjects with “borderline” diabetes were almost 70% more likely to later be diagnosed with Alzheimer’s dementia.  If they also had very high blood pressure on exam, the risk of the disease was even greater. 

You may have heard that diabetes can damage your heart, your eyes, and your kidneys.  But now you know that it can be hazardous to your brain as well.

The good news is that the diabetes risk may be improved upon with diet, exercise, weight loss, and medication when necessary.  If you can maintain good blood sugar control, you may be able to lower your risk of dementia as well as other complications such as stroke.  Conversely, diabetics who have poor blood sugar control are in the greatest jeopardy of developing dementia. 

You can read more about insulin resistance, how it promotes obesity, and how you can reverse this process at my website, The right diet and regular exercise are needed to keep insulin under control.

Diabetes Damages Brain Cells

Why does diabetes damage the brain?   High blood sugar is known to be damaging to both blood vessels and nerves throughout the body.  But some of the damaging effects of diabetes are related to higher than normal insulin levels due to the condition known as insulin resistance.

Resistance to insulin develops when blood sugar levels are chronically high.   Receptors for insulin are found throughout the body, including the brain.  Insulin controls many metabolic reactions.  It also acts as an escort to glucose, ushering it into cells when needed for energy. 

Insulin resistance is a condition in which the body begins to ignore insulin’s signals.  The body is forced to produce more and more insulin in order to trigger its receptors and do its job properly.  A vicious cycle of higher insulin production and increasing insulin resistance can develop.

How Does Insulin Do Its Damage?

Several mechanisms have been identified:

Diabetes and insulin resistance promote clogged arteries. In particular, very small vessels may become clogged, decreasing blood flow.  When this happens, the neurons are deprived of the nutrients they need for proper function and for repair.  They may atrophy or even die.  

With diabetes, glucose levels in the blood may fluctuate widely.  Insulin resistance also impedes the transport of insulin into the brain itself.  Since brain cells require glucose for energy,   they may be “running on empty” when blood glucose levels drop.  Very high blood sugar levels are also a problem since too much glucose is toxic to brain cells.

High insulin levels lead to more beta-amyloid. This protein forms the basis of the amyloid plaque seen with AD.  The toxic builds up accumulates between neurons, choking off their circulation and preventing communication with other neurons.

High insulin levels promote inflammation.   The “smoking gun” called inflammation stimulates abnormal amyloid protein production.  The inflammatory response also triggers the fire power of the immune system, which then wreaks havoc on blood vessels and neurons. 

AGEs damage the cortex of the brain. AGE (advanced glycation end) products are formed when blood sugar molecules attach themselves to a variety of structural and functional proteins molecules.  This process renders the proteins useless. High blood sugar levels lead to more AGEs, including a particularly virulent form called AGE-2.  AGE-2 is toxic to the neurons of the brain cortex, especially the hippocampal region associated with memory.  

Whew!  There are sure to be other mechanisms as well which have not yet been studied.  As you can see, high insulin levels as well as high blood sugar levels cause a lot of problems for the brain as well as for the rest of the body.

What Can You Do Now to Decrease Your Risk of Insulin Resistance and Diabetes?

There are things you can do to decrease your chance of having insulin resistance and diabetes.  These measures should also help protect you against the risk of developing many of the chronic diseases of aging.  To fight off Alzheimer’s disease as well as stroke and vascular dementia, make sure you are living as healthy a lifestyle as possible.

Don’t wait!  Begin now to lower your risk of diabetes and insulin resistance:

Check fasting blood levels of glucose, lipids, and insulin. Your fasting blood sugar should be around 90 mg/dl (greater than 110 mg/dl is suggestive of insulin resistance, greater than 126 md/dl suggests diabetes).    Your cholesterol profile reflects your insulin biochemistry.  To lower your risk, your triglyceride/HDL ratio should be less than 2.0.  A ratio greater than 4.0 suggests high insulin levels.   A healthy fasting insulin level should fall below 10 uUnits/ml, ideally less than 7 uUnits/ml. 

Maintain your ideal body weight.  Being overweight increases your risk of insulin resistance and type 2 diabetes.  Even losing as little as 5 – 7% of your body weight is enough to improve your health and decrease your risk.  To lose weight, reduce calorie intake and eat smaller, more frequent meals.  I have many more suggestions at

Exercise improves insulin sensitivity. You can benefit greatly from exercise even if you don’t lose weight.  So keep moving and be more active.  Build more muscle.  Muscle is metabolically active tissue which soaks up blood sugar.   Do the type of activities that you enjoy, so that you will keep it up on a daily basis.

Get enough sleep. 7 – 8 hours seems to be ideal for most.  Recent research showed that those who slept only 5 -6 hours per night had higher insulin levels.  For many this led to weight gain.  A sleep shortage increases insulin resistance as well as appetite-stimulating hormones.

Follow an insulin-lowering diet.  Avoid high glycemic carbohydrates such as sugars, syrups, and refined grains which raise blood sugar.  You may need to follow a lower carb diet and limit starchy foods like grains and potatoes.  Make sure to get plenty of omega-3 fats (think fish).  Avoid trans and saturated fats which increase insulin resistance.  Include high fiber foods which decrease hunger as well as lower insulin and cholesterol levels.

A healthy lifestyle can help keep your brain healthy and sharp well into old age.

Make your brain last as long as the rest of you!

(We'd like to thank Dr. Parsons again for another wonderful, exclusive health article for BrainReady...and we highly recommend visiting her too as it's packed with great diet & health articles, recommendations, and more!)

- The BrainReady Team

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