Saturday, August 11, 2007
MORE ON THE LATEST STUDY OF COFFEE GOODNESS
I mentioned this study yesterday but I have just now found the original journal article. See the abstract below. The authors acknowledge that coffee consumption varies according to all sorts of social factors ("a wide range of sociodemographic, lifestyle, and clinical variables") and have made some effort to allow for the possibility that it is an underlying social factor they are examining rather than coffee consumption itself. Such factors are however hard to measure and the fact that differences were observed only among women strongly points to a social rather than a physiological explanation for what was observed. My conjecture that the absolute differences would be small is also confirmed
The neuroprotective effects of caffeine: A prospective population study (the Three City Study)
By K. Ritchie et al.
Objective: To examine the association between caffeine intake, cognitive decline, and incident dementia in a community-based sample of subjects aged 65 years and over.
Methods: Participants were 4,197 women and 2,820 men from a population-based cohort recruited from three French cities. Cognitive performance, clinical diagnosis of dementia, and caffeine consumption were evaluated at baseline and at 2 and 4 year follow-up.
Results: Caffeine consumption is associated with a wide range of sociodemographic, lifestyle, and clinical variables which may also affect cognitive decline. Multivariate mixed models and multivariate adjusted logistic regression indicated that women with high rates of caffeine consumption (over three cups per day) showed less decline in verbal retrieval (OR = 0.67, CI = 0.53, 0.85), and to a lesser extent in visuospatial memory (OR = 0.82, CI = 0.65, 1.03) over 4 years than women consuming one cup or less. The protective effect of caffeine was observed to increase with age (OR = 0.73, CI = 0.53, 1.02 in the age range 65 to 74; OR = 0.3, CI = 0.14, 0.63 in the range 80+). No relation was found between caffeine intake and cognitive decline in men. Caffeine consumption did not reduce dementia risk over 4 years.
Conclusions: The psychostimulant properties of caffeine appear to reduce cognitive decline in women without dementia, especially at higher ages. Although no impact is observed on dementia incidence, further studies are required to ascertain whether caffeine may nonetheless be of potential use in prolonging the period of mild cognitive impairment in women prior to a diagnosis of dementia.
NEUROLOGY 2007;69:536-545
THERE REALLY IS SUCH A THING AS A FATHEAD
The study below shows that fatties have more white matter (a fatty substance) in their brains. No adverse effect of increased white matter was however shown. It is grey matter that does the thinking.
Brain White Matter Expansion in Human Obesity and the Recovering Effect of Dieting
By Lauri T. Haltia et al.
Context and Objective: Obesity is associated with several metabolic abnormalities. Recent studies suggest that obesity also affects brain function and is a risk factor for some degenerative brain diseases. The objective of this study was to examine the effects of weight gain and weight loss on brain gray and white matter structure. We hypothesized that possible differences seen in the brains of obese subjects would disappear or diminish after an intensive dieting period.
Methods: In part I of the study, we scanned with magnetic resonance imaging 16 lean (mean body mass index, 22 kg/m2) and 30 obese (mean body mass index, 33 kg/m2) healthy subjects. In part II, 16 obese subjects continued with a very low-calorie diet for 6 wk, after which they were scanned again. Regional brain white and gray matter volumes were calculated using voxel-based morphometry.
Results: White matter volumes were greater in obese subjects, compared with lean subjects in several basal brain regions, and obese individuals showed a positive correlation between white matter volume in basal brain structures and waist to hip ratio. The detected white matter expansion was partially reversed by dieting. Regional gray matter volumes did not differ significantly in obese and lean subjects, and dieting did not affect gray matter.
Conclusions: The precise mechanism for the discovered white matter changes remains unclear, but the present study demonstrates that obesity and dieting are associated with opposite changes in brain structure. It is not excluded that white matter expansion in obesity has a role in the neuropathogenesis of degenerative brain diseases.
The Journal of Clinical Endocrinology & Metabolism Vol. 92, No. 8 3278-3284
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Just some problems with the "Obesity" war:
1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).
2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.
3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.
4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.
5). Food warriors demonize salt and fat. But we need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. And Eskimos eat huge amounts of fat with no apparent ill-effects. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?
6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.
7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.
8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? And what about butter and margarine? They are just about pure fat. Surely they should be treated as contraband in kids' lunchboxes! [/sarcasm].
Trans fats:
For one summary of the weak science behind the "trans-fat" hysteria, see here. Trans fats have only a temporary effect on blood chemistry and the evidence of lasting harm from them is dubious. By taking extreme groups in trans fats intake, some weak association with coronary heart disease has at times been shown in some sub-populations but extreme group studies are inherently at risk of confounding with other factors and are intrinsically of little interest to the average person.
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