Thursday, December 28, 2006


It reproduces only a tiny part of the human experience of long-haul flight. And elderly humans DON'T die from jet-lag -- or we would all have heard of it years ago

A study that exposed elderly mice to the ravages of regular long-haul flights found most of them died. The University of Virginia study showed a majority of older mice died while being subjected to the equivalent of a Washington to Paris flight once a week for eight weeks, The Washington Post reported today. More intense forms of jet lag sped up the death rate in the elderly rodents, the study found.

Experts say the study is one of the first hard scientific looks into the health effects of jet lag. Younger mice seemed to rebound more quickly and were not immediately harmed by the jet lag. Simulated jet lag conditions were created by advancing and delaying the rodent's exposure to light. But researchers aren't sure what conclusions to draw from the results, the newspaper said.

Gene Block, the report's co-author, said older mice might be more susceptible to sudden light changes than younger mice. Or, he said, jet lag might be a health problem that builds up in younger subjects, causing future maladies. To further explore the issue, his researchers have launched another set of tests to determine whether jet lag causes long-term health consequences in younger and middle-age rodents, Mr Block said. Mr Block's study also hinted at what flyers have been saying for years - it's more difficult to adjust to time zone changes when flying east. The researchers found 53 per cent of elderly mice died when they were subjected to a simulated weekly flight from Washington to Paris over the eight-week study. The death rate dropped to 32 per cent of elderly mice on a simulated Paris to Washington route, according to the study, which was published last month in the journal Current Biology. Seventeen per cent of the mice in a control group died in the eight-week study.


Benefits of brittle bone drug 'last five years'

Millions of people who suffer from osteoporosis may be able to stop taking their medication and still feel the benefits, a long-term study suggests. The effects of the drug alendronate may last up to five years after a patient stops taking it, significantly boosting its cost-effectiveness, researchers say. According to a study published today, most post-menopausal women who took alendronate for five years and then stopped had no increased risk for non-vertebral fractures during the next five years.

Alendronate is part of the class of drugs known as bisphosphonates, which stop further loss of bone mass. Treatment for osteoporosis often continues indefinitely, but few studies have examined the long-term effects of using bisphosphonates — at a cost of about 80p a day — or stopping treatment after a certain period. The Fracture Intervention Trial Long-term Extension (Flex) study examined alendronate’s effect on bone mineral density (BMD) and fracture risk in 1,099 post-menopausal women with low BMD.

Dennis Black, of the University of California, San Francisco, and colleagues found that, compared with continuing alendronate, switching to a placebo for five years appeared to result in slight declines in BMD at the hip (-2.4 per cent) and spine (-3.7 per cent), but average levels were the same or above those ten years earlier, before treatment.

After five years, there was no significant difference in the cumulative risk of non-spinal fractures between those continuing to take the drug and those who had stopped. However, among those who continued to take the drug, there was a 55 per cent lower risk of clinically recognised spinal fractures, the authors report in the Journal of the American Medical Association.

“The BMD and bone marker changes suggest some residual effect from five years of alen- dronate treatment that is evident for at least five years after discontinuation,” the authors write. “We conclude that continuation of alendronate for ten years maintains bone mass and reduces bone remodelling [continuous turnover of bone mineral] compared with discontinuation after five years.

“The results confirm the safety of alendronate for up to ten years and suggest that, for many women, discontinuation of alendronate after five years for up to five more years does not significantly increase fracture risk, but women at high risk of clinical vertebral fractures, such as those with vertebral fracture or very low BMD, may benefit by continuing beyond five years.”

In an accompanying editorial, Cathleen Colon-Emeric, of Duke University Medical Centre, Durham, North Carolina, writes: “Women who have a good response to five years of bisphosphonate therapy and are not otherwise at increased risk of vertebral fracture can consider a ‘holiday’ of up to five years without therapy. This strategy would clearly improve the reported cost-effectiveness of bisphosphonates. Now . . . physicians may be able to begin telling women when they have had enough of a good thing.”



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? It is just about pure fat. Surely it 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.

The use of extreme quintiles to examine effects is in fact so common as to be almost universal but suggests to the experienced observer that the differences between the mean scores of the experimental and control groups were not statistically significant -- thus making the article concerned little more than an exercise in deception


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