Friday, May 28, 2010

What fun! Mediterranean diet 'could raise risk of heart attacks'

Though this study is about blood lipids among people who have already had heart attacks rather than diet as such

It has long been thought that a diet rich in olive oil, nuts and oily fish is good for health because it can reduce bad cholesterol levels. However, a study suggests that some heart attack patients may have genetic mutations that mean the diet increases their risk of suffering further cardiac problems.

It found that those at most risk of suffering subsequent heart attacks had large amounts of the high-density lipoprotein (HDL), or 'good' cholesterol', in their blood that destroys unhealthy trans fats in foods such as biscuits and cakes.

They also had more of a protein known as CRP which causes inflammation – suggesting this influences whether good cholesterol protects or endangers individuals.

The findings, published in Arteriosclerosis, Thrombosis, and Vascular Biology, could also explain disappointing results from a trial of an experimental drug called torcetrapib designed to increase HDL cholesterol. Manufacturers Pfizer had to halt it in 2006 due to a surprisingly excessive number of unexplained heart attacks and deaths that were linked with higher levels of good cholesterol.

Pathologist Professor James Corsetti, of the University of Rochester, New York, said: "It seems counter-intuitive that increasing good cholesterol – which we've always thought of as protective – leads to negative consequences in some people. "We've confirmed high HDL cholesterol is in fact associated with risk in a certain group of patients."

Out of 767 patients followed for two years, about 20 per cent at high risk of another heart attack also had high levels of HDL and CRP – the first study to find supposedly good cholesterol can harm a subgroup of people.

Co-researcher Prof Charles Sparks said: "The ability to identify patients who will not benefit from efforts to increase HDL cholesterol is important because they can be excluded from trials testing medications that aim to raise HDL cholesterol. "With these patients excluded researchers may find raising HDL cholesterol in the remaining population is effective in reducing cardiovascular disease risk." [speculation]

The researchers believe genetics and environmental factors – particularly inflammation – decide what effect good cholesterol has on patients. Given an inflammatory environment a person's unique set of genes determines whether HDL transforms from good to bad in the heart disease process.

In the high-risk subgroup of patients they also identified two genes associated with recurrent heart attacks – CETP which moves cholesterol away from the vascular system and is associated with HDL and p22phox which influences inflammation-related processes and is associated with CRP.

Prof Corsetti said: "Our research is oriented around the ability to better identify patients at high risk. "Identifying these patients and determining what puts them at high risk may be useful in choosing treatments tailored to the specific needs of particular patient subgroups. This gets us another step closer to achieving the goal of personalised medicine."

Despite the outcome of the torcetrapib trial drug companies are continuing to develop drugs to increase HDL cholesterol. Merck recently announced plans to launch a major clinical trial in 2011 to test whether anacetrapib – a chemical cousin of torcetrapib designed to raise good cholesterol – reduces the risk of heart attack and death.


Clean your teeth twice a day to keep a heart attack at bay

The usual epidemiological simple-mindedness. Keen brushers are probably very careful of their health generally and that is just one probable reason why they have less heart disease. Brushing itself is not likely to affect the heart

Those who rarely brush their teeth are more likely to suffer heart disease than those who brush twice a day

Brushing your teeth twice a day could save you from a heart attack.

Scientists say those who fail to keep their teeth clean have a higher chance of suffering heart problems.

It is well established that having gum disease makes you more prone to heart disease, but this is the first time a link has been made with brushing habits.

A study found that those who never or rarely brush their teeth are 70 per cent more likely to suffer heart disease than those who brush twice a day.

Previously, researchers have found that poor dental hygiene and bleeding gums can allow up to 700 types of bacteria to get into the bloodstream, increasing the risk of a heart attack regardless of how healthy the person is.

Bacteria entering the bloodstream may activate the immune system, making artery walls inflamed and narrowed, or attach directly to fatty deposits already present in the arteries, causing further narrowing.

In the latest study, researchers from University College London analysed data for more than 11,000 people with an average age of 50 taking part in the Scottish Health Survey.

Participants were asked how often they visited their dentist and how often they brushed their teeth, and medical histories were taken.

Just over six out of ten (62 per cent) visited their dentist every six months while 71 per cent said they brushed their teeth twice a day.

Over the next eight years, there were 555 cases of serious heart problems, of which 170 were fatal, says a report published online in the British Medical Journal.

The experts found that those who never or rarely brushed their teeth were 70 per cent more likely to suffer heart disease than those who brushed twice a day.

This held true even when factors likely to influence the results, such as obesity and smoking, were taken into account. Poor oral-hygiene was also linked to low-grade inflammation in the blood.

Researcher Professor Richard Watt said: 'Our results confirmed and further strengthened the suggested association between oral hygiene and the risk of cardiovascular disease.

Furthermore inflammatory markers were significantly associated with a very simple measure of poor oral health behaviour.

'Future experimental studies will be needed to confirm whether the observed association between oral health behaviour and cardiovascular-disease is in fact causal or merely a risk marker.'

Professor Damien Walmsley, scientific adviser to the British Dental Association, said: 'There are several studies linking a wide range of health conditions, such as heart disease, diabetes and even dementia, to poor oral health.

'However, further research is necessary to confirm whether these findings are just coincidental or have a definite cause and effect.

'Whatever the true position is, we can say with certainty that if people-brush their teeth twice a day with fluoride toothpaste, visit the dentist regularly and restrict sugary snacks to mealtimes, this will go a long way towards keeping their teeth and gums in a healthy state for life.'


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