Category Archives: Dementia

Does Diabetes Drug Pioglitazone Prevent Dementia?

Nobody knows. A recent report out of Germany suggests that pioglitazone does prevent dementia, but it’s not a very strong linkage. If it works, I wonder if it’s simply related to better control of blood sugar, which could be accomplished with a variety of means. Pioglitazone (aka Actos) is a type 2 diabetes drug in the TZD class. You could call it an “insulin sensitizer.”

The best popular press report I’ve seen is at Bloomberg.

German researchers went fishing for associations in a huge database of patients and drug usage. Their formal report hasn’t even been published yet. A five-year study was recently initiated to further investigate the possibility that piogoitazone prevents dementia. I doubt this will pan out.

Steve Parker, M.D.

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Another Study Finds the Mediterranean Diet Preserves Brain Function During Aging

Well, maybe that’s a bit of an overstatement. Preserved brain function and the Mediterranean diet were  positively associated in a study involving Americans in Utah. This fits with prior observations that the Mediterranean diet prevents dementia.

In the study at hand, the DASH diet (Dietary Approaches to Stop Hypertension) also protected the brain:

Higher levels of compliance with both the DASH and Mediterranean dietary patterns were associated with consistently higher levels of cognitive function in elderly men and women over an 11-y period. Whole grains and nuts and legumes were positively associated with higher cognitive functions and may be core neuroprotective foods common to various healthy plant-centered diets around the globe.

See the American Journal of Clinical Nutrition for details.

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Filed under Dementia, Health Benefits, Mediterranean Diet

High Blood Sugar Raises Risk for Dementia, Even For Non-Diabetics

dementia, memory loss, Mediterranean diet, low-carb diet, glycemic index, dementia memory loss

“Let’s work on getting those blood sugars down, honey.”

On the heels of a report finding no association between Alzheimer’s disease and abnormal blood sugar metabolism, MedPageToday features an new study linking high blood sugars to future development of dementia. And diabetics with sugar levels higher than other diabetics were more prone to develop dementia.

Some of you have already noted that not all cases of dementia are Alzheimer’s dementia. But Alzheimer’s accounts for a solid majority of dementia cases, about eight in 10 cases.

Some quotes from MedPageToday:

During a median follow-up of 6.8 years, 524 participants [of the 2,000 total] developed dementia, consisting of 74 with diabetes and 450 without. Patients without diabetes and who developed dementia had significantly higher average glucose levels in the 5 years before diagnosis of dementia (P=0.01). The difference translated into a hazard ratio of 1.18 (95% CI 1.04-1.33).

Among the patients with diabetes, glucose levels averaged 190 mg/dL in those who developed dementia versus 160 mg/dL in those who did not. The difference represented a 40% increase in the hazard for dementia (HR 1.40, 95% CI 1.12-1.76).

Steve Parker, M.D.

Reference: Crane PK et al. “Glucose Levels and Risk of Dementia” N Engl J Med 2013; 369: 540-548.

Reminder: Conquer Diabetes and Prediabetes is now available on Kindle.

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One More Reason to Exercise: Slow the Rate of Age-Related Memory Loss and Alzheimer’s Disease

…according to an article at MedPageToday. The 300+study participants were at high risk of Alzheimer’s dementia due to family history. The protective dose of exercise was at least 7.7 MET per hour/week. Please comment if you can translate that into something practical! Click for the definition of MET at About.com.

Old-school preparation for exercise; stretching actually doesn't do any good for the average person

Old-school preparation for exercise; stretching actually doesn’t do any good for the average person

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Yet Another Study Links Impaired Sugar Metabolism With Dementia

…according to an article at MedPageToday. A cohort of patients with mild to moderate Alzheimer’s were found to have unexpectedly high rates of impaired glucose tolerance or outright type 2 diabetes. We don’t know for sure if impaired glucose metabolism is a cause of dementia, or if some other factor links the two conditions. Until we have that answer, if I had impaired glucose metabolism, I’d work to improve it with loss of excess weight, exercise, and low-carb eating.

Here’s another article I wrote wondering if diabetes causes dementia.

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Omega-3 Fatty Acid Supplements Fail to Prevent Dementia

I like fish, but raw whole dead fish leave me cold

Supplementation with omega-3 fatty acids does not help prevent age-related cognitive decline and dementia, according to an article at MedPage Today.

The respected Cochrane organization did a meta-analysis of three pertinent studies done in several countries (Holland, UK, and ?).

The investigators leave open the possibility that longer-term studies—over three years—may show some benefit.

I leave you with a quote from the MedPage Today article:

And while cognitive benefits were not demonstrated in this review, Sydenham and colleagues emphasized that consumption of two servings of fish each week, with one being an oily fish such as salmon or sardines, is widely recommended for overall health benefits.

Steve Parker, M.D.

Reference:
Sydenham E, et al “Omega 3 fatty acid for the prevention of cognitive decline and dementia” Cochrane Database of Systematic Reviews 2012; DOI: 10.1002/14651858.CD005379.pub3.

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Metformin Impairs Brain Function In Some Users

 

 

Conquer Diabetes and Prediabetes

Metformin is the most-recommended drug for type 2 diabetes

…according to an article at MedPageToday. I consider this finding preliminary, but definitely something to keep an eye on. We need confirmatory data before taking action. Long-term metformin users should get vitamin B12 levels checked periodically in view of the well-established association of low levels in users. Low B12 impairs cognition and is easily preventable or treated.

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Deteriorating Brain Function Linked to High Insulin Levels and Insulin Resistance: Here’s How You Fight Back

dementia, memory loss, Mediterranean diet, low-carb diet, glycemic index, dementia memory loss

Don’t wait to take action until it’s too late

Insulin resistance and high blood insulin levels promote age-related degeneration of the brain, leading to memory loss and dementia according to Robert Krikorian, Ph.D.  He’s a professor in the Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati Academic Health Center.  He has an article in a recent issue of Current Psychiatry – Online.

Proper insulin signaling in the brain is important for healthy functioning of our brains’ memory centers.  This signaling breaks down in the setting of insulin resistance and the associated high insulin levels.  Dr. K makes much of the fact that high insulin levels and insulin resistance are closely tied to obesity.  He writes that:

“Waist circumference of ≥100 cm (39 inches) is a sensitive, specific, and independent predictor of hyperinsulinemia for men and women and a stronger predictor than body mass index, waist-to-hip ratio, and other measures of body fat.”

Take-Home Points

Dr. Krikorian thinks that dietary approaches to the prevention of dementia are effective yet underutilized.  He mentions reduction of insulin levels by restricting calories or a ketogenic diet: they’ve been linked with improved memory in middle-aged and older adults.

Dr. Krikorian suggests the following measures to prevent dementia and memory loss:

  • eliminate high-glycemic foods like processed carbohydrates and sweets
  • replace high-glycemic foods with fruits and vegetables (the higher polyphenol intake may help by itself)
  • certain polyphenols, such as those found in berries, may be particularly helpful in improving brain metabolic function
  • keep your waist size under 39 inches, or aim for that if you’re overweight

I must mention that many, perhaps most, dementia experts are not as confident  as Dr. Krikorian that these dietary changes are effective.  I think they probably are, to a degree.

The Mediterranean diet is high in fruits and vegetables and relatively low-glycemic.  It’s usually mentioned by experts as the diet that may prevent dementia and slow its progression.

Read the full article.

I’ve written before about how blood sugars in the upper normal range are linked to brain degeneration.  Dr. Krikorian’s recommendations would tend to keep blood sugar levels in the lower end of the normal range.

Steve Parker, M.D.

PS: Speaking of dementia and ketogenic, have you ever heard of the Ketogenic Mediterranean Diet?  (Free condensed version here.)

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Filed under Carbohydrate, Dementia, Glycemic Index and Load, ketogenic diet

Upper Normal Blood Sugars Linked To Brain Shrinkage

MRI scan of brain

MRI scan of brain

Healthy bodies keep blood sugar levels in a fairly narrow range.  You might think you’re fine if you’re anywhere within the defined normal range.  Think again.  Australian researchers found that folks with fasting blood sugars toward the upper end of the normal range had more degeneration (atrophy) in parts of the brain called the hippocampus and amygdala, compared to those in the low normal range.  Degeneration in those areas is often manifested as dementia.

The hippocampus is critical for learning and memory formation and retention.  The amygdala is also involved in memory as well as emotion.  The two areas are intimately connected, literally.

How Was the Study Done?

Over 250 study participants aged 60 to 64 years had normal brains at baseline and were free of prediabetes and diabetes.  They were mostly caucasian.  MRI brain scans were done at baseline and again four years later.  Significant atrophy (shrinkage) was seen in the hippocampus and amygdala over time, with greater atrophy seen in those with higher baseline fasting glucose levels.

Fasting blood sugar was measured only once, at the start, and ranged from 58 to 108 mg/dl (3.2 to 6.0 mmol/l).  (Fasting glucose of 108 would be prediabetes according to the American Diabetes Association, but not by the World Health Organization.)  Participants weren’t tested for deterioration of cognition (actual thinking).

So What?

The results of the study at hand are consistent with others that link higher rates of dementia with diabetes.  Diabetics, even when under treatment, usually have higher average blood sugars than non-diabetics.  The study authors speculate that damage from higher blood sugars may be mediated by inflammation and abnormal blood clotting (prothrombotic factors and platelet activation).

The Mayo Clinic recently reported that diets high in carbohydrates and sugar increase the odds of developing cognitive impairment in the elderly years.

It’s interesting to contemplate whether non-diabetics and diabetics would have less risk of developing dementia if blood sugars could be kept in the lower end of the normal range.  How could you do that?  Possibilities include:

  • avoid sugars and other refined carbohydrates
  • limit all carbohydrates
  • favor low-glycemic-index foods over high
  • regular exercise, which helps maintain insulin sensitivity (insulin is a major blood sugar regulator)
  • avoid overweight and obesity, which helps maintain insulin sensitivity
  • for diabetics: all of the above plus drugs that control blood sugar

Steve Parker, M.D.

Reference:  Cherbuin, Nicolas, et al.  Higher normal fasting plasma glucose is associated with hippocampal atrophy: The PATH Study.  Neurology, September 4, 2012, vol. 79, No. 10, pp: 1,010-1,026.  doi:10.1212/WNL.0b013e31826846de

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Filed under Dementia, Diabetes Complications

Which Diseases Do Vegetables and Fruits Prevent?

Potential answers are in the American Journal of Clinical Nutrition (2012).  I quote:

For hypertension, coronary heart disease, and stroke, there is convincing evidence that increasing the consumption of vegetables and fruit reduces the risk of disease. There is probable evidence that the risk of cancer in general is inversely associated with the consumption of vegetables and fruit. In addition, there is possible evidence that an increased consumption of vegetables and fruit may prevent body weight gain. As overweight is the most important risk factor for type 2 diabetes mellitus, an increased consumption of vegetables and fruit therefore might indirectly reduces the incidence of type 2 diabetes mellitus. Independent of overweight, there is probable evidence that there is no influence of increased consumption on the risk of type 2 diabetes mellitus. There is possible evidence that increasing the consumption of vegetables and fruit lowers the risk of certain eye diseases, dementia and the risk of osteoporosis. Likewise, current data on asthma, chronic obstructive pulmonary disease, and rheumatoid arthritis indicate that an increase in vegetable and fruit consumption may contribute to the prevention of these diseases. For inflammatory bowel disease, glaucoma, and diabetic retinopathy, there was insufficient evidence regarding an association with the consumption of vegetables and fruit.

It bothers me that vegetables and fruits are lumped together: they’re not the same.

All of my diets—Advanced MediterraneanLow-Carb Mediterranean, and Ketogenic Mediterranean—provide plenty of fruits and vegetables.

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Filed under cancer, Dementia, Fruits, Heart Disease, Stroke, Vegetables