Saturday, July 07, 2007

Asthma in the genes too

A PREVIOUSLY unknown gene may be the solution to the puzzle of childhood asthma. The link between the gene and the disorder is so strong that scientists may have a complete understanding of what causes asthma within three years, predicts the team leader, British respiratory physician William Cookson. "I'm upbeat that we're going to do it," said Dr Cookson, with the National Heart and Lung Institute at Imperial College London.

Along with European and US colleagues, Dr Cookson reported overnight in the journal Nature that mutations in the novel gene ORMDL3 had a strong association with childhood asthma. "It's a potential target for therapy," Dr Cookson said. "But we're not completely sure what this gene does." His team found the mutations and the gene by comparing DNA from thousands of people with and without childhood asthma.

Molecular biologist Carolyn Williams, head of the genetics unit at the Lung Institute of Western Australia, said the result was extraordinary. "In all the years we've been looking. we've never found such a strong line between a genetic mutation and asthma," she said. Although numerous genes have shown small effects on susceptibility to childhood asthma, Dr Cookson said none had proved as closely tied as ORMDL3.

New data analysed by epidemiologist Guy Marks of Sydney's Woolcock Institute of Medical Research showed roughly 11 per cent of Australian children had asthma. "This is an important study in adding to knowledge of genetic risk factors of asthma," said Associate Professor Marks, who also heads the Australian Centre for Asthma Monitoring. Associate Professor Marks said childhood asthma was caused by a combination of poorly understood genetic and environmental factors.

Peter Le Souef, a respiratory physician at the University of Western Australia in Perth, praised Dr Cookson's team's gene-scanning prowess. "They're the best in the world at it," he said. But Professor Le Souef said Dr Cookson's three-year timeline was overly optimistic. "We need to see how the finding replicates in further populations of children, as well as knowing its function," he said. To that end, Dr Cookson's group hopes to nail down ORMDL3's role in the body, asthmatic and otherwise.


"Alternative" medicine bad for pregnancy

But it COULD just be that women who are less healthy are more likely to take risks with quack remedies

Women who use complementary therapies while trying to conceive by IVF are less likely to get pregnant than those who use conventional medicine alone, research indicates. A study of 818 Danish fertility patients revealed that pregnancy rates were about 20 per cent lower among users of alternative medicine, such as reflexology and acupuncture, than among those who did not use such treatments. The findings could mean that complementary medicines that have a biological effect, such as herbal remedies or nutritional supplements, interfere with fertility drugs or other aspects of IVF treatment.

Women who turn to alternative medicine, however, tend to be more stressed by their infertility, and may have been trying for longer to get pregnant. The lower success rate could reflect that these patients are willing to try anything to improve their chances of having a child. "It may be that complementary therapies diminish the effectiveness of medical interventions," said Jacky Boivin, of Cardiff University, who led the research. "Or it may simply be that persistent treatment failure encourages women to seek out complementary and alternative therapies."

Edzard Ernst, professor of complementary medicine at Exeter University, said: "Similar associations have been made in cancer patients. Those who use complementary or alternative medicine [CAM] are on average more distressed and more depressed. The important question is whether the chicken or the egg came first. "The most likely explanation is that those women who are prone to stress and have more health problems are more likely to try CAM. So CAM could only be a marker, and not the cause of stress and lower success rates."

The study, which was conducted with the University of Copenhagen, found that 31 per cent of the fertility patients had used an alternative treatment, with reflexology and nutritional supplements the most popular. Such patients suffered from greater stress, and the researchers said that they could have turned to complementary medicine to address this. Previous small studies have indicated that techniques such as acupuncture may help with relaxation.

Dr Boivin said: "We found that women who went on to use complementary therapies, for example reflexology and nutritional supplements, during their treatments were more distressed and emotionally affected by their fertility problems than nonusers. "This difference in stress may mean that women used complementary and alternative therapies for stress reduction, and if this were the case it would be important for future research to establish whether these achieve this goal more effectively than conventional psychological therapies."

The team now intends to follow up the patients over five years to assess pregnancy rates over a longer period. "It is important to do this because we are concerned that, with persistent treatment failure, women might become more and more susceptible to deceptive advertising about ineffective complementary and alternative therapies or other unproven treatments," Dr Boivin said.


Organic produce has more flavonoids: So what?

The flavonoid faith rolls on

Organic fruit and vegetables may be better for the heart and general health than eating conventionally grown crops, new research has found. A ten-year study comparing organic tomatoes with standard produce found that they had almost double the quantity of antioxidants called flavonoids which help to prevent high blood pressure and thus reduce the likelihood of heart disease and strokes. Alyson Mitchell, a food chemist, who led the research at the University of California, believes [Isn't faith wonderful?] that flavonoids can also help to stave off some forms of cancer and dementia.

She found that levels of quercetin and kaempferol, both flavonoids, were on average 79 and 97 per cent higher, respectively, in organic tomatoes. Her findings are due to be published in full in the Journal of Agricultural and Food Chemistry. Dr Mitchell said that previously it had been hard to make comparisons between organic and conventionally grown produce because of difficulties in comparing soil quality, irrigation practices and the handling of harvested produce. But for this study researchers used data from a long-term project in which standardised farming techniques were used to reveal trends in crop productivity. The team believes [More faith!] that the different levels of flavonoids in tomatoes are due to the absence of fertilisers in organic farming.

Plants produce flavonoids as a defence mechanism; they are triggered by nutrient deficiency. Feeding a plant with too many nutrients, such as inorganic nitrogen commonly found in conventional fertiliser, curbs the development of flavonoids. The lower levels of flavonoids in conventional tomatoes were caused by "over-fertilisation", the research team concluded.

The Soil Association is now pressing the Food Standards Agency to review its guidance on the merits of organic as opposed to conventional fruit and vegetables. Peter Melchett, its policy director, said that there was now a rapidly growing body of evidence which showed significant differences between the nutritional composition of organic and nonorganic food.

Recent research in Europe found that organic tomatoes contained more vitamin C, B-carotene and flavonoids than conventionally grown tomatoes. Organic peaches and organic apple puree were also found to have more antioxidants. Lord Krebs, the former chairman of the Food Standards Agency and now Master of Jesus College, Oxford, said that even if such benefits existed, higher flavonoid levels did not make organic food healthier. "This depends on the relevance of the differences to the human body," he said. "Tomato ketchup has higher levels of lycopene [a strong antioxidant] than either organic or conventional tomatoes. So if you wanted lots of lycopene you should eat tomato ketchup."

The Food Standards Agency, however, has commissioned a three-year study into the benefits of flavonoids. It said: "There is accumulating evidence that dietary flavonoids. . . may in large part explain the cardiovascular disease benefits of increased fruit and vegetable intake."



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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