Tag Archives: Alzheimer

400 failed Alzheimer’s drugs

15 Jan

An article in The Washington Post examines why it is so hard to find an effective drug to treat Alzheimer’s disease:

These setbacks pile on to an already depressing situation: more than 400 failed clinical trials since the last Alzheimer’s drug — which only treats the symptoms of the disease, temporarily — was approved more than a decade ago.

(…)

Alzheimer’s is a formidable foe for a number of reasons. The brain isn’t easy to access, and much about how it works remains mysterious, even as scientific knowledge has moved forward. Doctors can’t take easy, repeat biopsies to see whether a drug is working.

Trials are long and expensive. It has become increasingly clear that it is necessary to treat patients early in the disease, and then wait to see if the disease is prevented or slowed.

Patients, though they are affected in heartbreaking ways, typically are unable to act as advocates for more funding or research when they are in the throes of the disease — unlike cancer or AIDS patients.

Does extra virgin olive oil prevent Alzheimer’s disease?

12 Jan

Sound too good to be true? It probably is. Here is a post on the topic by Joy Victory:

To deconstruct how this went off the rails, let’s start with the university news release sent to journalists: “Temple study: Extra-virgin olive oil preserves memory & protects brain against Alzheimer’s.”

That’s a headline that surely got journalists’ attention. It’s not until after two very long opening paragraphs extolling the virtues of the nearly magical powers of extra virgin olive oil that we find out who, exactly this was tested on.

Mice.

Andrew Gelman gives his take:

I looked briefly at the published research article and am concerned about forking paths, type M errors, and type S errors. Put briefly, I doubt such strong results would show up in a replication of this study.

Is Alzheimer’s caused by brain atherosclerosis?

3 Jan

Please  understand that this explanation if one of a number of competing hypotheses. Dr. Greger makes his case here:

Transcranial direct current stimulation for dementia?

1 May

Possibly, according to a paper presented at the recent American Academy of Neurology Annual Meeting:

To assess efficacy of transcranial direct current stimulation (tDCS) for improving picture naming abilities in individuals with mild dementia, researchers conducted a double-blind, cross-over study among 12 individuals. Study participants received 10 sessions of training on picture naming plus 30 minutes of anodal tDCS applied to the parietal lobe or sham simulation. Evaluation occurred before stimulation, at the final stimulation session, 2 weeks after stimulation and 2 months after stimulation.

Study participants who received tDCS significantly improved in picture naming, compared with those who received sham stimulation.

This seems like a strong study design and the results are striking. Normally, you would not expect improvement in a memory test on people suffering from dementia. Indeed, drugs, such as Donepezil,  used for treatment of dementia, only claim to reduce the rate of decline, not to cause improvement.

Note that this is a conference paper and has not yet been published in a peer reviewed journal. It would be important to know the magnitude of the effect and to see the research replicated.

“Sugary beverage intake and preclinical Alzheimer’s disease”

26 Apr

For some years I have been intrigued by the idea that Alzheimer’s disease might be a special type of diabetes (sometimes called Type 3 Diabetes). You can read the evidence for this hypothesis here.

A recent study published in the journal Alzheimer’s and Dementia reports the observation that sugary drink consumption may be linked to Alzheimer’s disease. Here is the abstract:

Introduction
Excess sugar consumption has been linked with Alzheimer’s disease (AD) pathology in animal models.

Methods
We examined the cross-sectional association of sugary beverage consumption with neuropsychological (N = 4276) and magnetic resonance imaging (N = 3846) markers of preclinical Alzheimer’s disease and vascular brain injury (VBI) in the community-based Framingham Heart Study. Intake of sugary beverages was estimated using a food frequency questionnaire.

Results
Relative to consuming less than one sugary beverage per day, higher intake of sugary beverages was associated with lower total brain volume (1–2/day, β ± standard error [SE] = −0.55 ± 0.14 mean percent difference, P = .0002; >2/day, β ± SE = −0.68 ± 0.18, P < .0001), and poorer performance on tests of episodic memory (all P < .01). Daily fruit juice intake was associated with lower total brain volume, hippocampal volume, and poorer episodic memory (all P < .05). Sugary beverage intake was not associated with VBI in a consistent manner across outcomes.

Discussion
Higher intake of sugary beverages was associated cross-sectionally with markers of preclinical AD.

This result would be consistent with the Type 3 Diabetes hypothesis. But note that the study is correlational and based on self-report. Sugary beverage consumption might be a proxy for some other variable.

“Prevention may prove the best way to manage the dementia epidemic”

20 Mar

So argues this important piece in Scientific American (sorry, it’s behind a paywall). So far drugs that target Alzheimer’s have been disappointing. Our best evidence suggests that lifestyle interventions (exercise, improvements in diet, and cognitive engagement) really do help.

LED light flickering as a treatment for Alzheimer’s?

14 Dec

Don’t get your hopes up yet. The findings reflect animal research, but here is the story from ScienceDaily:

Using LED lights flickering at a specific frequency, researchers have shown that they can significantly reduce the beta amyloid plaques seen in Alzheimer’s disease in the visual cortex of mice. This treatment appears to work by stimulating brain waves known as gamma oscillations, which the researchers discovered help the brain suppress beta amyloid production and invigorate cells responsible for destroying the plaques.

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