HgbA1c (hemoglobin A1c) is measure of average blood sugar levels over the previous three months. From a 2018 study:
In this community-based population, we observed a significant trend for cognitive decline over a 10 year period among individuals aged ≥50 years with normoglycaemia, prediabetes or diabetes at baseline. Additionally, HbA1c levels were linearly associated with subsequent cognitive decline in memory and executive function (but not orientation) irrespective of diabetes status at baseline.
Source: HbA1c, diabetes and cognitive decline: the English Longitudinal Study of Ageing | SpringerLink
h/t to Jan at The Low-Carb Diabetic
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Exercise also seems to protect against memory loss and dementia
Keep your eyes on this development, folks. Potential game-changer. And a boon to Big Pharma. From NBCnews.com…
Lowering blood pressure to recommended levels can prevent dementia and the memory and thinking problems that often show up first [mild cognitive impairment], researchers reported Wednesday.
People whose top blood pressure reading was taken down to 120 were 19 percent less likely to develop mild cognitive impairment, the loss of memory and brain processing power that usually precedes Alzheimer’s, the study found. And they were 15 percent less likely to eventually develop cognitive decline and dementia.
It may take a few more years before the study conclusively shows whether the risk of Alzheimer’s was actually reduced because of the lower blood pressure,the researchers said.
It’s the first intervention that has been clearly demonstrated to lower rates of mental decline.
The findings come from a large trial of blood pressure called the Systolic Blood Pressure Intervention Trial, or SPRINT.
It has already found that lowering systolic blood pressure — the top number in a blood pressure reading — to 120 or less can prevent stroke, heart attacks, kidney disease and other problems.
Source: Tight blood pressure control can cut memory loss, study finds
He’s not worried about adequate dietary calcium
The paleo diet is relatively low in calcium content. So is that a reason to take a calcium supplement? Probably not. Calcium supplements are problematic. They may increase the risk of heart attacks. They may raise the odds of premature cardiac death in men. High calcium consumption increased the risk of death in Swedish women.
MedicalNewsToday has a brief report on dementia in women with cerebrovascular disease and calcium supplements:
“Calcium supplements may increase the risk of developing dementia in senior women with cerebrovascular disease, finds a study published in Neurology, the medical journal of the American Academy of Neurology.
Women who took calcium supplements were twice as likely to develop dementia.Cerebrovascular diseases are conditions caused by problems that affect the blood supply to the brain. The four most common types of cerebrovascular disease are stroke, transient ischemic attack (TIA), subarachnoid hemorrhage, and vascular dementia.”
Source: Dementia risk increased with calcium supplements in certain women – Medical News Today
“More basic research is critical.”
Several scientific studies, but not all, link type 2 diabetes with Alzheimer’s disease. Some go so far as to say Alzheimer’s is type 3 diabetes.
My Twitter feed brought to my attention a scientific article I thought would clarify the relationships between diabetes, carbohydrate consumption, and Alzheimer’s dementia (full text).
Click the full text link to read all about insulin, amylin, insulin degrading enzyme, amyloid–β, and other factors that might explain the relationship between type 2 diabetes and Alzheimer’s dementia. You’ll also find a comprehensive annotated list of the scientific studies investigating the link between diabetes and Alzheimer’s.
Bottom line: We still don’t know the fundamental cause of Alzheimer’s disease. A cure and highly effective preventive measures are far in the future.
Action Plan For You
You may be able to reduce your risk of Alzheimer’s disease by:
- avoiding type 2 diabetes
- preventing progression of prediabetes to diabetes
- avoiding obesity
- exercising regularly
- eating a Mediterranean-style diet
Scientists have no idea whether a Stone Age diet prevents dementia.
Carbohydrate restriction helps some folks prevent or resolve obesity, prediabetes, and type 2 diabetes. A low-carb Mediterranean diet is an option in my Advanced Mediterranean Diet (2nd edition).
Steve Parker, M.D.
Reference: Schilling, Melissa. Unraveling Alzheimer’s: Making Sense of the Relationship Between Diabetes and Alzheimer’s Disease. Journal of Alzheimer’s Disease, 51 (2016): 961-977.
…according to an article at the Journal of the American Medical Association. The study involved Chicago-area residents who had provided information about their eating habits. After death, their brains were biopsied, looking for typical pathological findings of Alzheimers Disease.
Rich sources of omega-3 fatty acids include salmon, sardines, herring, trout, and mackerel
Participants who ate seafood at least once a week had fewer Alzheimers lesions in their brains, but only if they were carriers of a particular gene the predisposes to Alzheimers. The gene is called apolipoprotein E or APOE ε4.
You’ve heard that seafood may be contaminated with mercury, right? The seafood eaters in this study indeed had higher brain levels of mercury, but it didn’t cause any visible brain damage.
The Mediterranean diet, relatively rich in seafood, has long been linked to a lower risk of dementia.
A weakness of the study is that the researchers didn’t report results of clinical testing for dementia in these participants before they died. You can have microscopic evidence of Alzheimers disease on a biopsy, yet no clinical diagnosis of dementia.
Steve Parker, M.D.
Exercise your brain
I saw a patient at the hospital a couple years ago who had been brought in by ambulance after suffering some trauma (not to his brain). He couldn’t call any friends or relatives to let them know what was going on because he didn’t have his cellphone. His phone had all his contact numbers so he had no reason to memorize any. Would you be in the same boat?
DailyMail has an interesting article on whether our use of technology is making us dumber. If we turn over mental tasks like navigation and math to computers, do our brains waste away? Will we be seeing more and earlier cases of age-related dementia? E-mentia?
This is worth keeping an eye on.
Steve Parker, M.D.
PS: The five other members of my household all have cellphones. The only number I’ve memorized is my wife’s.
Pioglitazone (aka Actos) is a type 2 diabetes drug in the TZD class. You could call it an “insulin sensitizer.” A recent report out of Germany suggests that pioglitazone prevents 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.
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.
The NYT’s Well blog has the details. The brain’s hippocampus is a critical center for memory. Alzheimers disease is associated with a gene called apo-E4. Carriers of that gene who exercise regularly have less shrinkage of the hippocampus than non-exercisers.
To PROVE that regular exercise prevents dementia-related shrinkage of the hippocampus, you’d have to force some folks to exercise and stop others who wanted to exercise. A couple years later, scan their brains and compare the two groups. That study may never be done.
Another way to preserve your memory could be to keep your fasting blood sugars closer to the lower end of the normal range, rather than the higher end. That strategy may prevent degeneration of your hippocampus and amygdala.
The Mediterranean diet also seems to prevent or forestall dementia.
Steve Parker, M.D.
The following quote is from an Instant Expert paper on intelligence. It’s full of interesting facts such as the typical difference in IQ between strangers is 17 points. It answers the question whether an enriched school or home environment can increase intelligence.
There are ways of slowing or reversing losses in cognitive function. The most effective discovered so far is physical exercise, which protects the brain by protecting the body’s cardiovascular health. Mental exercise, often called brain training, is widely promoted, but it boosts only the particular skill that is practised – its narrow impact mirroring that of educational interventions at other ages. Various drugs are being investigated for their value in staving off normal cognitive decline, but for now preventive maintenance is still the best bet – avoid smoking, drinking to excess, head injuries and the like.
Also, I think the Mediterranean diet helps preserve brain function, but it’s difficult to prove.
MRI scan of brain
The article mentions overload of patients’ brains when medical care is too complicated:
Given the complexity of self-care regimes, it is hardly surprising that some people make dangerous errors or fail to comply. The effective management of diabetes, for example, requires a person to keep blood sugar levels within a healthy range, which means coordinating diet, exercise and medication throughout the day, which in turn requires planning for contingencies, recognising when blood sugar is veering too high or low, knowing how to regain control and conceptualising the imperceptible but cumulative damage caused by failing to maintain control. There is no set recipe for people with diabetes to follow – their bodies and circumstances differ. Moreover, they get little training, virtually no supervision and no days off. Effectively managing your diabetes is a cognitively complex job and poor performance has serious consequences, including emergency room visits, lost limbs or eyesight, and even death. The lower the diabetic person’s IQ, the greater the risks.
You’ll also learn about the Flynn effect and possible explanations for it:
Over the past century, each successive generation has answered more IQ test items correctly than the last, the rise being equivalent to around 3 IQ points per decade in developed nations. This is dubbed the “Flynn effect” after the political scientist James Flynn, who most thoroughly documented it. Are humans getting smarter, and if so, why?
I’m more inclined to think Idiocracy describes our future.
Steve Parker, M.D.
h/t James Fulford
Sugar, according to John Yudkin and Robert Lustig, among others. The Age has the details. A quote:
[Robert] Lustig is one of a growing number of scientists who don’t just believe sugar makes you fat and rots teeth. They’re convinced it’s the cause of several chronic and very common illnesses, including heart disease, cancer, Alzheimer’s and diabetes. It’s also addictive, since it interferes with our appetites and creates an irresistible urge to eat.
This year, Lustig’s message has gone mainstream; many of the New Year diet books focused not on fat or carbohydrates, but on cutting out sugar and the everyday foods (soups, fruit juices, bread) that contain high levels of sucrose. The anti-sugar camp is not celebrating yet, however. They know what happened to Yudkin and what a ruthless and unscrupulous adversary the sugar industry proved to be.
In 1822, we in the U.S. ate 6.2 pounds of sugar per person per year. By 1999, we were up to 108 pounds.
An occasional teaspoon of sugar probably won’t hurt you
The U.S. Department of Agriculture estimates that added sugars provide 17% of the total calories in the average American diet. A typical carbonated soda contain the equivalent of 10 tsp (50 ml) of sugar. The average U.S. adult eats 30 tsp (150 ml) daily of added sweeteners and sugars.
On the other hand, Fanatic Cook Bix found a study linking higher sugar consumption with lower body weight, which you might think would protect against type 2 diabetes, heart disease, and some cancers.
Read the rest at The Age. It’s mostly about John Yudkin.
Steve Parker, M.D.
h/t Jamie Scott