Thursday, September 10, 2009

Alcohol and coffee linked to heartbeat problems

This sounds like more epidemiological nonsense and shows a foolish willingnes to generalize from atypical samples. It also fails to look at the big picture -- which also suggests benefits from coffee and alcohol intake. It's just "publish or perish" fodder

Drinking more than ten alcoholic drinks a week or four cups of strong coffee each day can increase the risk of developing an irregular heartbeat, new research suggests. Two studies presented at the European Society of Cardiology congress in Barcelona found that alcohol and caffeine intake can affect the chances of developing an abnormal heart rhythm, known as atrial fibrillation.

About 46,000 people in Britain are diagnosed with atrial fibrillation every year. The condition greatly increases the risk of having a stroke, heart attack or other cardiac problems.

The study into alcohol, carried out on 8,830 men and women in Britain, Scandinavia and the United States, found that those who drank the equivalent of ten standard drinks — about 15 units a week — had an 80 per cent increased risk of being diagnosed with the condition within five years.

The Department of Health advises [on no scientific basis] that men should drink no more than 21 units of alcohol a week, and women no more than 14. A 125ml glass of red or white wine or half a pint of 5 per cent lager contain about 1.5 units. A standard large glass of wine in a bar is 250ml.

The patients in the study had an average age of 67 and were already receiving treatment for high blood pressure but had no previous signs of atrial fibrillation. They were followed up for an average of 4.8 years, during which time heart scans revealed atrial fibrillation in 5.7 per cent of patients who reported drinking more than ten units a week, compared to 3.9 per cent of patients who drank less or no alcohol at all.

Inger Ariansen, who led the study at Oslo University Hospital, suggested that ten standard drinks could be regarded as a threshold for increased risk of atrial fibrillation, although she pointed out that different countries defined the amount of alcohol contained in a typical drink differently.

The second study, by researchers at the University of Modena, found that drinking more than the equivalent of four espresso shots a day could increase the risk of arrhythmias in people without known heart disease, even if they otherwise had a healthy diet.

Peter Weissberg, medical director of the British Heart Foundation, said that the recommended limits for drinking alcohol a week were formulated to avoid the risk of liver disease and other drink-related health problems. “But there is no doubt that some patients are more susceptible to the effects of alcohol on the heart and it may be that a subset of people who metabolise alcohol differently are at increased risk of atrial fibrillation.”

He added that he was not aware of any direct evidence that drinking caffeine increased the risk of atrial fibrillation, “but it wouldn’t be surprising if you found that”.


Moths, caterpillars may replace laboratory mice

If mice and moths are so similar, it's no wonder rodent findings often do not generalize well to human beings

MOTHS, caterpillars and fruit flies could soon take the place of millions of mice used every year by scientists testing drugs, researchers said. Biologists have discovered that certain key cells in mammals and insects react in the same way when attacked by infections and produce similar chemical reactions to fight them off. The findings could mean up to 80 per cent of the mice used for testing new pharmaceutical compounds may no longer be needed, offering drug firms sizeable time and cost savings.

"It is now routine practice to use insect larvae to perform initial testing of new drugs and then to use mice for confirmation tests," Kevin Kavanagh, a biologist from the National University of Ireland, said. "This method of testing is quicker, as tests with insects yield results in 48 hours whereas tests with mice usually take four to six weeks. And it is much cheaper too."

Mr Kavanagh and his colleagues found that neutrophils, white blood cells that form part of the mammalian immune system, and haematocytes, cells that carry out similar work in insects, react in the same way to infecting microbes. Both the insect and mammalian cells produce chemicals with a similar structure which move to the surface of the cells to kill the invading microbe, they found. The immune cells then enclose the microbe and release enzymes to break it down.

"We used insects instead of mammals for measuring how pathogenic a bacterium or fungus is, and found a very good correlation between the results in mammals and insects," Mr Kavanagh said. "The reason for this ... is that the innate immune system of mammals is almost 90 per cent similar to that of insects."


1 comment:

John A said...

Coffee [and alcohol] - "The patients in the study had an average age of 67 and were already receiving treatment for high blood pressure but had no previous signs of atrial fibrillation."

Golly. An existing problem affecting the heart (amongst other organs) actually might get worse upon reaching the late sixties. Hey, does that hold for hair going grey as well?