Scientists reveal how L-Arginine cleans arteries


London: Scientists at Imperial College London have used a new chemical imaging technique to reveal how a simple dietary supplement cleans up arteries.

The new technique could one day help in the fight against atherosclerosis – the disease in which arteries get clogged up with plaque and fats, suggests the research research. (published in the August 2009 edition of the Journal of the Royal Society Interface).

Atherosclerosis is the disease underlying most heart attacks and strokes and it is characterised by lesions in the arteries, made of fats, collagen and cells.

The lesions cause artery walls to harden and thicken, which severely restricts the flow of blood around the body and they can also rupture, leading to heart attacks and strokes. Understanding the precise chemical composition of an individual’s lesions is important because the ones with higher levels of a type of fat, called cholesteryl ester, are more prone to rupture.

The team behind the new imaging technique, which is known as Attenuated Total Reflection Fourier Transform Infrared Spectroscopic Imaging (ATR-FTIR imaging), believe that with further refinement, it could become a useful tool for doctors wanting to assess a patient’s lesions.

For example, by combining fibre optic technology with ATR-FTIR imaging, the researchers believe doctors could carry out real-time inspections of patients with atherosclerosis, in order to assess the progress of the disease and establish which patients are at the greatest risk of complications.

Currently, doctors can use ultrasound to assess the size and location of lesions but they need to take biopsies of lesions in order to determine their chemistry. This is a complex and invasive procedure.

The researchers say the ATR-FTIR imaging could potentially improve current imaging techniques because it could combine imaging and chemical analysis, which would provide a comprehensive and accurate picture of a patient’s lesions in one procedure. In the present study, the researchers demonstrated that ATR-FTIR imaging was able to reveal the precise composition and size of the lesions and the levels of elastin, collagen and cholesteryl ester in them.

The ATR-FTIR imaging technology works by using infrared light to identify different chemical molecules, which are mapped by an array detector to create a ‘chemical photograph’.

The researchers used the technique to study the effects of age and an amino acid called L-arginine on the composition of lesions in cholesterol-fed rabbits. The work appeared to confirm that dietary L-arginine can remove lesions in the arteries of mature rabbits.

The researchers say further studies need to be done before the ATR-FTIR imaging could be used for patient care.

Lead-author, Professor Sergei Kazarian, from the Department of Chemical Engineering and Chemical Technology at Imperial College London, says:

“Atherosclerosis can be a dangerous condition and our hope is that with further work, our approaches could ultimately be used to determine which patients are most at risk of complications. That way, doctors can target treatments at those patients who most need it, in order to prevent strokes and heart attacks.”

This research was funded by the Engineering and Physical Sciences Research Council.

Aspirin does reduce heart and stroke attack risks, say US experts


New York: Aspirin should be recommended to reduce the risk of heart attack in men aged 45 – 79 and to reduce the risk of stroke in women aged 55 – 79 who do not have heart disease, the US Preventive Services Task Force (USPSTF) has recommended.(1)

The USPSTF(2) states that men aged 45 – 79 should be encouraged to take aspirin when the potential benefit of a reduction in the risk of a heart attack outweighs the potential harm of an increase in gastrointestinal bleeding; women aged 55 – 79 should be encouraged to take aspirin when the potential benefit of a reduction in the risk of ischaemic stroke outweighs the potential harm of an increase in gastrointestinal bleeding.

The recommendations are based on the latest evidence of the benefits of aspirin. If implemented in Europe, they would greatly increase the number of people taking aspirin to prevent heart attack or stroke.

Taking aspirin to prevent heart attack or stroke by people who are not known to have heart disease is known as primary prevention. An individual’s risk is estimated from their sex, age, smoking status, blood pressure and cholesterol level. European guidelines recommend primary prevention with aspirin when the risk of a heart attack exceeds 10% per year;(3) in the UK, primary prevention is recommended for people over 50 years old when the 10-year risk exceeds 20%.(4) Aspirin is universally recommended for people who have already had a heart attack or stroke (secondary prevention).

The USPSTF provides estimates of the numbers of cardiovascular events avoided by primary prevention with aspirin and the risk of gastrointestinal bleeding and stroke. Assuming aspirin reduces heart attacks by 32%, its benefits for men aged 45 – 79 outweigh the risks when the 10-year risk of a heart attack is 4%. For women aged 55 – 59, the benefit:risk ratio becomes favourable when the 10-year risk of stroke is 3%. The USPSFT says the benefits of aspirin are not proven for men or women in younger age groups, among people aged 80 or over, or for reducing the risk of heart attack among women.(1)

The decision to take aspirin should be made jointly between doctors and patients, the USPSFT emphasises, but the recommendation should be stronger as the potential benefit increases.


Chocolate body booster

Los Angeles: Cocoa, the main ingredient in chocolate, is good for the circulation, according to scientists at the University of California.

So eating some chocolate may reduce the risk of blood clots by improving blood circulation through the heart and brain.

Cocoa, contains flavonols, naturally occurring antioxidants, which can help the body protect itself from the diseases of ageing, such as cancer and heart disease, by eradicating the free radicals that can damage arteries and blood vessels.

Cocoa has already been credited with health properties that can improve blood vessel function and may reduce clot formation. The new research shows flavonol-rich cocoa improves blood flow which, scientists say, also lowers the risks of clotting. The study is pubished in the Journal of Cardiovascular Pharmacology.

Carl Keen, professor of Nutrition at the University of California, said their findings contradicted popular views about chocolate.

‘This news catches people off guard as it contradicts popular views: chocolate can actually be good for you when it’s rich in flavonols.

New clot-busting drug offers hope to stroke victims

London: Trials of a new clot-busting drug for stroke victims are taking place in the US and Canada.

If successful, the drug, by UK company Vernalis and codenamed V10153, could go into the final phase of clinical trials next year.

The drug contains a protein that activates when it comes into contact with a clot and breaks it up. It is thought that the drug will be particularly helpful to those who have ischemic strokes, the most common form of stroke triggered by a blood clot in the brain. It can be given up to nine hours after a stroke and still be viable, unlike most current medications.

Vernalis medical director Dr John Hutchison said that clotbusting drugs should be administered as quickly as possible after a stroke, but that it was often difficult to get a patient scanned and treated within three hours.

Tomatoes help fight blood clots, say scientists

Aberdeen: Tomatoes can help fight deep vein thrombosis, according to an investigation by scientists at the Rowett Institute in the UK.

They have discovered that a yellow fluid around the seeds contains an anti-clotting substance which could help sufferers of the potentially fatal condition.

DVT usually occurs when people are inactive such as sitting for ours on planes and it is thought that as many as 12 per cent of long haul passengers may suffer from clots.

Although aspirin can be helpful some people are allergic to it and others may suffer bleeding in the stomach.

Professor Asim Duttaroy who led the research which has been published in the American Journal of Clinical Nutrition said that tomotoes were entirely safe and the fruit can be used to prevent rather than cure clots.

The anti-clotting substances in the tomato include flavonoids, which are known to help prevent heart attacks and cancer. The substances have already been patented under the name Fruitflow and added to the Sirco brand of fruit drinks. Drinking a quarter of a pint of the juice a day – the equvalent of six tomatoes – will give protection against clots, say the scientists. The benefits last for 18 hours.

The research also revealed that blood ‘stickiness’ was reduced by an average of 70 per cent in 220 volunteers who drank juice containing the tomato extract. Tests showed that in 97 per cent of people the substance changed the thickness of the blood so that it was less likely to clump together as a clot.