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“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.

Can rosemary improve cognition?

3 Apr

Perhaps, but only at very low doses. Dr. Greger explains. Note that the study suggests that too much rosemary might interfere with cognition.

I did find the results about aromatherapy interesting. I had always assumed that the idea was implausible. But Dr. Greger points to a study that shows that the volatile compounds used can actually be measured in the blood. This doesn’t mean that aromatherapy works, only that it’s plausible.

High blood pressure and dementia

9 Nov

A paper published in the journal Hypertension, here is the abstract:

Background—Age-related dementia, most commonly caused by Alzheimer disease or cerebrovascular factors (vascular dementia), is a major public health threat. Chronic arterial hypertension is a well-established risk factor for both types of dementia, but the link between hypertension and its treatment and cognition remains poorly understood. In this scientific statement, a multidisciplinary team of experts examines the impact of hypertension on cognition to assess the state of the knowledge, to identify gaps, and to provide future directions.

Methods—Authors with relevant expertise were selected to contribute to this statement in accordance with the American Heart Association conflict-of-interest management policy. Panel members were assigned topics relevant to their areas of expertise, reviewed the literature, and summarized the available data.

Results—Hypertension disrupts the structure and function of cerebral blood vessels, leads to ischemic damage of white matter regions critical for cognitive function, and may promote Alzheimer pathology. There is strong evidence of a deleterious influence of midlife hypertension on late-life cognitive function, but the cognitive impact of late-life hypertension is less clear. Observational studies demonstrated a cumulative effect of hypertension on cerebrovascular damage, but evidence from clinical trials that antihypertensive treatment improves cognition is not conclusive.

Conclusions—After carefully reviewing the literature, the group concluded that there were insufficient data to make evidence-based recommendations. However, judicious treatment of hypertension, taking into account goals of care and individual characteristics (eg, age and comorbidities), seems justified to safeguard vascular health and, as a consequence, brain health.

The butter brain hypothesis

10 Oct

I always enjoyed reading the late Seth Robert’s blog. He never hesitated to question orthodoxies and always had some interesting new idea. However, some of the things he advocated were troubling. One example, of this was the butter brain hypothesis, the idea that consumption of butter might improve cognitive performance.

The idea is not implausible. The brain, after all, contains many lipids and the idea that consuming certain lipids might improve its performance does not sound unreasonable. The problem is butter is high in saturated fats and has been linked to heart disease.

I know, I know, many recent news reports tell us that “butter is safe” or that “butter is back.” These kind of person-bites-dog stories are popular in the media, but the science around saturated fats and cardiovascular disease is well established.

Here is an article from the New York Times reflecting on evolution and the dietary needs of the brain.

And here is a recent paper on the dangers of saturated fats. The abstract reads:

In recent years, many nutrition news headlines exclaimed that saturated fat was not linked to heart disease, leaving the public confused about whether to limit intake, as has been the dietary recommendation for several decades. However, a more nuanced look at the evidence indicates that high saturated fat diets are in fact not benign with respect to heart disease risk. Dietary recommendations should emphasize replacing saturated fats typical in red and processed meats, and certain tropical oils and dairy forms, with healthier polyunsaturated and monounsaturated fat-rich foods, such as nuts, olive oil, and fatty fish, as well as healthy sources of carbohydrates, such as fiber-rich whole-grain foods, rather than refined-grain and sugar-laden foods.

 

Why are they called essential fatty acids?

5 Oct

I actually didn’t know until I watched this video:

 

 

I’ll post the second video on Friday.

Meet world memory champion Jonas Von Essen

26 Sep

You can read an interview with him here.

“I think that aiming high and practicing above your comfort level is very important. If you aim low you will land low. If you go fast and forget a lot you will gradually adapt to the higher tempo and forget less and less. It made all the difference to me.”

Von Essen has also received some attention for his diet.

“Diabetes of the brain”

5 Aug

The idea that Alzheimer’s disease might be a kind of diabetes has been floating around the research community for a number of years. Now it’s beginning to garner some media attention. Here is a 2008 paper that explains the hypothesis:

‘For nearly three decades of relatively intense research on AD, the inability to interlink this constellation of abnormalities under a single primary pathogenic mechanism resulted in the emergence and propagation of various heavily debated theories, each of which focused on how one particular component of AD could trigger a cascade that contributes to the development of all other known abnormalities. However, reevaluation of the older literature revealed that impairments in cerebral glucose utilization and energy metabolism represent very early abnormalities that precede or accompany the initial stages of cognitive impairment1 and led us to the concept that impaired insulin signaling has an important role in the pathogenesis of AD and the proposal that AD represents “type 3 diabetes.”’

This suggests that the behaviors that protect against diabetes may also protect Alzheimer’s disease.

 

 

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