Sunday, May 06, 2007

Now pistachios get a nod

Incorporating pistachios into the diet can significantly reduce cholesterol and help to prevent narrowing of the arteries, research suggests. Nuts have a reputation as being salty, fatty and high in calories. In fact, they contain protein, fibre and in many cases their fats are of the healthy type. In 2003 the US Food and Drug Administration allowed nuts - including walnuts, peanuts, almonds and pistachios - to carry a "qualified health claim" asserting there was evidence that they could lower the risk of heart disease, because of their effects on cholesterol.

The latest trial, focusing on pistachios, adds to the evidence by showing that one or two handfuls of the nuts can reduce cholesterol levels. Volunteers who ate three ounces (85g) of pistachios a day for one month lowered their total blood cholesterol by 8.4 per cent. Crucially, levels of "bad" cholesterol, low-density lipoprotein (LDL), went down by 11.6 per cent, while the balance between LDL and "good" cholesterol, high-density lipoprotein (HDL), was also changed. Participants on the pistachio diet had less LDL relative to HDL after four weeks.

The volunteers did not simply add pistachios to their normal diet. Instead, they were put on diets that lowered the total fat they consumed, and also on lower-fat diets that incorporated either 1.5 or 3oz of pistachios a day. [So the study proves nothing about pistachios] The findings were presented at Experimental Biology, a meeting in Washington DC.


Heart attack gene

A test that determines whether people have an inherited vulnerability to heart attacks is to be developed after scientists discovered a genetic variant that can double the risk of having one at an early age. The DNA test, which is being developed by an Icelandic company, has been assisted by two separate studies that identified a genetic profile that increases a person's susceptibility to heart attacks and coronary heart disease. The most damaging variant, which is carried by between a fifth and a quarter of the white European population, raises the chances of a heart attack, at any age, by up to 60 per cent. In early middle age, it has an even greater impact: it doubles the risk for men younger than 50, and for women younger than 60, researchers found.

Coronary heart disease is the biggest cause of death in developed countries such as Britain. In England, about 275,000 people have a heart attack each year, and 110,000 people die of heart disease.

While many other factors, particularly diet, exercise and smoking, have a greater impact on the risk than genes, the discovery should eventually allow doctors to identify patients with a high genetic vulnerability. They could then be advised to change their lifestyle accordingly, to reduce the risks, or treated at an earlier stage with cholesterol-lowering drugs such as statins. In the longer term, insights into how the genetic variant increases risk might also be used to assist the design of new drugs.

The Reykjavik-based biotechnology company deCODE Genetics, which conducted one of the studies, said that it now intends to develop a test that would incorporate other genetic variants that contribute to heart attacks. It said in a statement: "deCODE plans to bundle this discovery with other genetic variants it has linked to risk of heart attack into a DNA-based test for gauging inherited risk of myocardial infarction [heart attack]. "The company believes that such a test, particularly for those with other risk factors, may enable individuals and their doctors to adopt more informed and thus potentially more effective prevention regimes."

Ruth McPherson, director of the University of Ottawa Heart Institute in Canada, who led the second study, said: "If we can identify genetic factors which influence heart disease risk, over and above known risk factors, we can do a better job of identifying those people who will benefit most from early intervention to reduce their risk." The two studies, which are published in the journal Science, scanned hundreds of thousands of single-letter DNA spelling mistakes known as single nucleotide polymorphisms (SNPs, pronounced "snips"), in search of variants that might be linked to heart attacks. Both alighted on an SNP that lies close to two genes called CDKN2A and CDKN2B. Each person inherits two copies of this stretch of DNA, one from each parent. When people inherit two copies of the SNP variant, they have a subtantially higher risk of heart disease than those with two normal copies.

The Icelandic study found an increased risk of around 60 per cent, while the Canadian researchers put their risk at 30 to 40 per cent higher. One normal copy paired with one copy of the variant raised the risk by 15 to 20 per cent. The deCODE study also looked at the risk of early heart attacks, before the age of 50 in men and 60 in women. It found that two copies of the variant doubled the risk, while one copy increased it by 49 per cent.

Independent researchers welcomed the findings. However, they cautioned that it is likely to take some time before genetic tests are developed or used in clinics. Genes remain less important than lifestyle factors in the onset of heart disease, they said. Professor Peter Weissberg, Medical Director of the British Heart Foundation (BHF), said: "Trying to find genes that put some families at an increased risk of heart attacks is like trying to find a collection of needles scattered amongst a field full of hay stacks. "The significance of these two studies is that two independent research teams have homed in on the same hay stack - a region of DNA within chromosome 9. "This makes it very likely that they are close to identifying a needle - an important gene in that region. "However, this will take a lot more research and - once found - the gene will be only one of several factors that are important. This research represents an important step along a very long journey, but a step in the right direction."

Tim Chico, of the University of Sheffield, said: "This is very interesting scientifically, but it won't change the way patients are investigated or treated at the moment. "We must not forget that 90 per cent of the risk of a heart attack comes from things like smoking, cholesterol, diet, lack of exercise and diabetes. "Whatever our genetic make-up, we can all reduce our chances of heart disease by improving our lifestyle."


Maggots cure superbug: "Maggots are being used to help successfully treat MRSA patients in record time, according to a study by the University of Manchester. Researchers used green bottle fly larvae to treat 13 diabetics whose foot ulcers were contaminated with MRSA. All but one were cured within a mean period of three weeks, instead of the usual 28 for conventional treatment. Professor Andrew Boulton, who published the results in Diabetes Care, will now do further tests, funded by Diabetes UK. Maggots eat dead tissue and bacteria, leaving healthy tissue to heal. The group of diabetics, aged between 18 and 80, had sterile larvae applied between two and eight times - depending on the size of foot ulcer - for four days at a time. All but one was cleared of the superbug. "This is very exciting," Professor Boulton said yesterday. "If confirmed in a randomised controlled trial, larval treatment would offer the first noninvasive and risk-free treatment of this problem."


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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