Diabetes, Obesity, & The Brain

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There is very substantial evidence that Type 2 Diabetes significantly raises the odds that one will develop Alzheimer’s or other forms of dementia. Here are some presentations:

Connections Between Diabetes and Alzheimer’s Disease
Diabetes and Alzheimer’s linked
Alzheimer’s Disease & Diabetes
How Diabetes Affects Your Brain

There is also strong evidence that being overweight or obese raises the odds that one will develop Type 2 diabetes. Here are some articles:

How Obesity Increases The Risk For Diabetes
Adult obesity and type 2 diabetes
Diabetes and Obesity

Just being overweight, without diabetes, can still have effects on the brain:
Brains of overweight people look ten years older than those of lean peers

And being overweight together with having diabetes further affects your brain:
Diabetes, weight can combine to alter brain, study says

All the links above have been added to Alzheimer’s > Risk Factors.

Category: Risk Factors

Advance Directive for Dementia

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Advance Care Directives concerning general medical care are recognized throughout all the states (for example, see the American Bar Associations list Links to State-Specific Advance Directive Forms). More recently, advance care directives specifically aimed at dementia have begun to appear. The point of advance directives is to have a plan in place and to have discussed your wishes with family, potential caregivers, and your doctors — while you are still capable.

A fairly simple straight-forward dementia-oriented directive has been developed by a Washington state internist, and is available as a pdf download at Health Directive for Dementia. The directive was documented by an essay in the JAMA at Advance Directives for Dementia – Meeting a Unique Challenge. Both of these links are available at ADVANCE DIRECTIVE FOR DEMENTIA. A media article about this work appeared at One Day Your Mind May Fade. At Least You’ll Have a Plan.

A more extensive dementia-oriented directive, with detailed directions, can be found at Alzheimers Disease and Dementia Advance Directive , with a general introduction at Alzheimer’s Disease and Dementia Mental Health Advance Directive. This directive apparently has legal weight in Washington state. It is not clear whether Advance Directives for Dementia have yet gained legal weight in other states.

Whatever the legal status of these Advance Directives for Dementia, it is important for anyone at any risk for dementia to engage in discussions of advance care with family, friends, and doctors, and to make their wishes known while they are able.

All the links above have been added to the top of Alzheimer’s > Coping & Caregivers and to the top of Alzheimer’s > General & Resources

Various Risk Factors

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In this post we’ve grouped articles and reports on several (independent) risk factors that have been reported in the past several years.

The first is the effects of the brain-dwelling parasite Toxoplasma gondii, often transmitted to humans by contact with cat feces.
Media article:
http://www.sciencealert.com/mind-altering-parasite-transmitted-by-cats-linked-to-several-brain-disorders
Research report:
Toxoplasma Modulates Signature Pathways of Human Epilepsy, Neurodegeneration & Cancer

Next is a study of how hearing loss could portend a greater risk for dementia later in life.
Media article:
Hearing loss could pose greater risk of potential dementia in later life – study
Research report:
SELF-REPORTED HEARING LOSS, COGNITIVE PERFORMANCE, AND RISK OF MCI: FINDINGS FROM THE WISCONSIN REGISTRY FOR ALZHEIMER’S PREVENTION

Next is a study on how, contrary to being purely negative (and presumably a primary sign of Alzheimer’s), the accumulation of amyloid beta may in fact be a response to the presence of infection.
Media articles:
Antimicrobial Mechanism Gone Rogue May Play Role in Alzheimer’s Disease
Human amyloid-beta acts as natural antibiotic in the brain: Alzheimer’s-associated amyloid plaques may trap microbes
Research abstract:
Amyloid-β peptide protects against microbial infection in mouse and worm models of Alzheimer’s disease.

Finally is a study of the interaction of certain heart treatments and the possible increase in potential for dementia.
Media article:
Warfarin, AF May Each Contribute to Dementia Risk in Atrial Fibrillation
Medical media article:
Among warfarin users, patients with AF at increased risk for dementia

All links have been added to Alzheimer’s > Risk Factors

Category: Announcements

Added Sugar: Again The Bad Guy — It Can Kill

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Sugar is definitely not too good for your health. We’ve collected a number of media articles about the bad effects of added sugar in our diets. The articles contain references to the original research publications.

Eating too much added sugar increases the risk of dying with heart disease
Sweet Stuff: How Sugars and Sweeteners Affect Your Health
How Does Too Much Sugar Affect Your Body?
More Proof Sugar Can Kill
Is Sugar Really Bad for You? It Depends

All the links have been added to Health > Diet

Category: Diet

Exercise: Again & Again, Like Notorious RGB

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Boring? Sometimes. Worthwhile? Sure. Benefits while aging? Can be fantastic.

One of the sad and unpleasant effects of aging for a great many people is the gradual loss of muscle mass. But apparently it doesn’t have to be that way. Two studies of master athletes in their 60s and 80s show that such athletes preserve a greater number of “motor units” in their legs: pairs of muscle fibers together with neurons connecting them to the spinal cord. With age, there is a tendency for the neurons to die. In younger people, new neurons are generated to replace the ones that die. However, in older people, they are not replaced, leading to the death of the originally attached muscle fiber. Two studies of older master athletes show that serious exercise can resist this scenario.

Here are links to two media articles about the research on both 60- and 80-year old master athletes:
Can the inevitable age-related decrement in motor unit number and stability be out run?
Exercise Makes Our Muscles Work Better With Age
Here is a link to the research based on 60-year-olds:
Motor unit number estimates in masters runners: use it or lose it?
And here is a link to the research based on 80-year olds:
Motor unit number and transmission stability in octogenarian world class athletes

So — master-level athletes can maintain muscle mass. But, you say, they must spend an awful lot of time at it. Well sure, as the saying goes: No pain, no gain, including the pain of time spent. But what if you’ve gotten into middle or advanced age masquerading as a couch potato? Is it all over for you? Fortunately, not.

A recent media article describes how intense strength training, combined with good nutrition, can hold the line or even reverse it:
How to build muscle as age tears it down

Here’s the research report mentioned in the article above about counteracting muscle weakness and physical frailty in very elderly people by using high-intensity resistance exercise training:
Exercise Training and Nutritional Supplementation for Physical Frailty in Very Elderly People

And now for the inspiration! Ruth Bader Ginsburg (the notorious RGB) is an Associate Justice of the Supreme Court of the United States, is 85 years old, and works out twice-weekly in the Supreme Court gym with her personal trainer. “She attributes her long career as a liberal legal icon to the sweat time she puts in with her trainer.” Her trainer has written an “exercise along with RGB” book:
The RBG Workout: How She Stays Strong . . . and You Can Too!

Here’s a media article about the book:
Get fit with the Ruth Bader Ginsburg workout

And just for fun, here’s a video of Stephen Colbert trying to workout out with the notorious RGB:
Colbert attempts Ruth Bader Ginsburg’s workout

All links have been added to Health > Physical Exercise

Diet Soda And Dementia And Stroke

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Just about a year ago, a study examining the associations of drinking artificially sweetened soda drinks made something of a splash. The study found that people consuming at least a can of so-called diet drinks every day were 2.96 times more likely to suffer an ischaemic stroke and 2.89 times more likely to develop Alzheimer’s disease than those who drank them less than once a week. The study — like many — could not establish a causal relationship either way, only a definite association. But “the best current evidence suggests that when it comes to reducing your risk of dementia, what is good for your heart is also good for your head.”

Here are four media articles about the work:
Stroke and dementia risk linked to artificial sweeteners, study suggests
Diet sodas may be tied to stroke, dementia risk
Is soda bad for your brain? (And is diet soda worse?)
Diet Soda and Dementia: What You Need to Know
Here is a link to the research publication:
Sugar- and Artificially Sweetened Beverages and the Risks of Incident Stroke and Dementia
And here is a link to a collection of expert researcher reactions to the publication:
expert reaction to artificially-sweetened fizzy drinks, stroke and dementia

The links have all been added to Alzheimers > Risk Factors and Health > Diet.

Too Many Hours Sitting Shrinks A Brain Memory Area

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The medial temporal lobe (MTL) includes the hippocampus, and is essential to the processing and storage of long-term memories. Recent research demonstrates that in people over 45, the number of hours spent sitting per day is inversely related to the thickness of the MTL. Crudely put, too many hours sitting can reduce your ability to remember. Since it is already known that sedentary behavior is linked to an increased risk of heart disease, diabetes and premature death in middle-age and older adults, this most recent work adds another disturbing element to the argument against sitting too much.

While the research appears to show that physical activity, even at high levels, is insufficient to offset the harmful effects of sitting for extended periods, the work is preliminary in that the study focused on hours spent sitting, and did not take into consideration whether participants took breaks during long stretches of sedentary behavior. The researchers said that this could be a limitation of their results.

Here are links to two media articles on the work:
Sitting Too Much Can Change Your Brain & Impact Your Memory, A New Study Says
Too Much Sitting May Shrink the Part of Your Brain Tied to Memory
Here is a link to the research article:
Sedentary behavior associated with reduced medial temporal lobe thickness in middle-aged and older adults

All the links have been added to Aging, Physical Exercise, and Alzheimers > Risk Factors.

New Biological Definition Of Alzheimer’s Advances

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Historically, Alzheimer’s Dementia (AD) has been defined by visible symptoms, simply because that was all that was available. Around the mid 1990’s, various researchers began pushing for the development of a biologically-based specification of the disease, separate from the manifested symptoms. Among other things, this allows reasoning about the onset of AD before manifestation of symptoms, much like cancer or heart disease. It is believed that the AD process may begin decades before any outward sign of memory loss or other decline.

In 2007, leading AD clinicians formed an international working group (IWG) and proposed using amyloid PET scans, MRI, CSF (cerebrospinal fluid) levels of Aβ and tau, genetic testing, brain structural changes, and subtle cognitive changes to diagnose AD at an earlier stage than before. The NIA/AA (National Institute of Aging, and the Alzheimer’s Association) set up a separate leadership group, and in 2011 it proposed a related set of diagnostic guidelines for AD research that utilized separate criteria for three stages of disease: preclinical AD, mild cognitive impairment, and dementia. The current NIA/AA research framework draws on these two efforts and their personnel.

The workers stress, both in the framework publication and in an associated editorial, that this work is directed at research, and will only slowly begin appearing in the clinical context. But it is expected that the new framework will markedly improve research communication and advances.

Links to media articles on the new framework:
New biological research framework for Alzheimer’s seeks to spur discovery
Alzheimer’s disease redefined: New research framework defines Alzheimer’s by brain changes, not symptoms
New Definition of Alzheimer’s Hinges on Biology, Not Symptoms

Links to two different publications of the framework:
NIA-AA Research Framework: Toward a biological definition of Alzheimer’s disease
NIA-AA Research Framework: Toward a biological definition of Alzheimer’s disease

All the links have been added to Neuro-Psych and to Alzheimers > Neurology & Neuroplasticity

Conflict! New Neurons or Not?

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Do human brains keep generating new neurons in the hippocampus throughout life, or not?

Two studies, just published within a month of each other, come down on opposite sides of that question.

The first link below is a well-written media article discussing the two research papers and the possible grounds for the conflict:
Do Older Brains Make New Neurons or Not?

Next are a link to a media article on the “no-new-neurons” work, together with the research abstract:
Your brain stopped making new cells at age 13, study claims
Human hippocampal neurogenesis drops sharply in children to undetectable levels in adults

And here is a link to a media article on the “new-neurons-all-through-life” work, together with a link to the full research article:
Surprise! Scientists find signs of new brain cells in adults as old as 79
Human Hippocampal Neurogenesis Persists throughout Aging

Finally, to give rats their due, here are links to a media article and to the research article, on work showing that strong physical exercise causes rat brains to increase the rate at which new hippocampal neurons are created:
Physical exercise increases adult hippocampal neurogenesis in male rats provided it is aerobic and sustained.
Sustained aerobic exercise increases adult neurogenesis in brain

All the links have been added to Neuro-Psych.

Maybe Flashing Lights For Alzheimer’s Therapy?

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Mice again, but not drugs. Instead, it’s the promising use of strobe-type flashing lights to modify brain waves (neuromodulation) to induce changes beneficial to Alzheimer’s sufferers.

It has been previously noted that both human Alzheimer’s sufferers and the mice models of Alzheimer’s exhibit disrupted gamma waves, which are the highest frequency waves and are associated with higher cognitive events. The study placed mice, genetically engineered to mimic Alzheimer’s symptoms, in a box with strobe lights flashing at 40 cycles per second for an hour a day. This stimulated the visual cortex of the mice to generate more gamma waves, which set in motion an apparent sequence of biological events: A change in gene expression causes microglia (immune cells in the brain) to change shape, going into scavenger mode, where they better perform their usual housekeeping role, clearing away cellular debris, including amyloid-β.

Note how complex the brain and how difficult the science: In Brain Inflammation & Alzheimer’s, we discussed work showing that Alzheimer’s-type inflammatory response on the part of microglia can lead to increase in the deposit of amyloid-β, whereas the present work shows the microglia being stimulated to improve the removal of amyloid-β.

Here is a link to a recent Nature magazine news feature article on the MIT work and related work on the role of brain waves. The article is an excellent explication of the work and how it affects how the brain works:
How flashing lights and pink noise might banish Alzheimer’s, improve memory and more

Below are links to a number of media articles on the work. The first group deals with the MIT group’s earlier report from 2016:
Flashing light therapy’ for Alzheimer’s
Beating Alzheimer’s With Brain Waves
Unique visual stimulation may be new treatment for Alzheimer’s
LED Lights May Be a Promising New Alzheimer’s Treatment, MIT Study Says
Toward Treating Alzheimer’s Disease with Brain Waves
Here is the earlier research article:
Gamma frequency entrainment attenuates amyloid load and modifies microglia

Here are links to media articles on the more recent research:
Alzheimer’s Memory Loss May Be Reversible, MIT Study Says
How does the Sp3-HDAC2 Complex Reduce Synaptic Function in Alzheimer’s?

And here is the more recent research report:
The Transcription Factor Sp3 Cooperates with HDAC2 to Regulate Synaptic Function and Plasticity in Neurons

Light therapy (sitting bathed in light every morning) has been successfully used for treating the form of depression known as Seasonal Affective Disorder (SAD) (see e.g., Take Light, Not Drugs). If this strobe-approach to Alzheimer’s is successful with humans, Alzheimer’s treatment could utilize a similar therapeutic approach, or even possibly the two therapies could be combined when appropriate.

All of the links have been added to Alzheimer’s > Treatment