“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
Carbohydrate restriction helps many folks prevent or resolve obesity, prediabetes, and type 2 diabetes.
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.
LCHF Mediterranean diet
…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 clinically diagnosis of dementia.
Steve Parker, M.D.
Filed under Dementia, Fish
Adult life is a battle against gravity. Eventually we all lose.
“Death rates from both of these cancers [breast in women, colon in men] were about half as high at an altitude of greater than 1000 meters (3300 feet). The study also found about a 30% reduction in deaths from coronary artery disease at >1000 meters.
This accords well with a number of other studies. For example, “Lower Mortality From Coronary Heart Disease and Stroke at Higher Altitudes in Switzerland“. This study found 22% less heart disease death for every +1000 meters in altitude, and 12% less stroke death.
“Association Between Alzheimer Dementia Mortality Rate and Altitude in California Counties“: This study found about half the death rate from Alzheimer’s at an altitude of 1600 meters vs that at sea level.
There’s less diabetes at high altitude.”
Source: Higher Altitude Means Much Lower Death Rates – Rogue Health and Fitness
MRI scan of brain
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.
The Mediterranean diet also seems to prevent or forestall dementia.
Steve Parker, M.D.
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.
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.