Caffeine

(Reuters Health) - Women with heart disease who down a few cups of coffee each day tend to live as long as those who avoid the beverage, a large study finds.

The results was reported in the American Journal of Clinical Nutrition. In theory, coffee could be problematic because it has caffeine and other compounds that can raise blood pressure or have other negative effects on the cardiovascular system. But some studies have found that coffee drinkers have no increased risk of a second heart attack or premature death. A few others have even hinted at protective effects from coffee.In this study, which followed nearly 12,000 U.S. nurses with a history of heart disease or stroke, those who regularly drank caffeinated coffee were no more likely to die than non-coffee-drinkers during the study period - which for some was more than 20 years.

Researchers found no link between a woman's coffee intake and her risk of death from heart attack, stroke or any other cause. And that was true even of women who downed four or more cups per day."What this study shows is that, in a general population, there's no obvious harm, or benefit, to consuming coffee after a heart attack," said Ahmed El-Sohemy, an associate professor at the University of Toronto who has studied coffee intake and heart health. The problem is that certain individuals may benefit from some caffeine, while others may be harmed, according to El-Sohemy, who was not involved in the new study.Some research, for example, has linked coffee drinking to increased risks of high blood pressure in people who are naturally "slow metabolizes" of caffeine. But the reverse pattern has been seen in people who quickly process caffeine: more coffee, lower heart risks.

The findings, Lopez-Garcia said, "support the idea" that people with heart disease who already drink coffee do not have to give it up. But she also advised checking with your doctor, particularly if you have uncontrolled high blood pressure or other conditions that could be aggravated by caffeine -- like sleep problems or anxiety.

El-Sohemy was even more cautious. It is hard to make individual recommendations on safe coffee intake, according to the researcher, because of genetic variations in people's caffeine metabolism. "I don't see how any results can be interpreted from studies that don't take this genetic difference into account," El-Sohemy said. Tests for genetic variations in the enzyme that processes caffeine are not routinely available, he noted.

SOURCE: http://bit.ly/kUXi5R American Journal of Clinical Nutrition, online May 11, 2011.

A gene test that predicts the risk of a stroke

Adults at risk of either prostate cancer or an erratic heart beat that can lead to strokes can now be identified early by genetic testing. About one in 20 elderly people suffer from atrial fibrillation, a condition in which turbulent blood flow raises the risk of blood clots, which can then lodge in the brain and cause a stroke.

Now an Icelandic company, deCODE, has announced in the journal Nature that it has found a variation in the human DNA sequence which raises the risk of atrial fibrillation, and used it as the basis of a test which will make it possible to identify those who will benefit the most from treatment. The firm's researchers found two "spelling mistakes" or single-letter variations in the human genetic code which increase the risk of atrial fibrillation by about 70 per cent and 40 per cent, doubling that risk if two copies of the variants are carried.

Because of the link with stroke, the company believes testing for these variants will provide doctors with a cost-effective means of identifying those who should be intensively monitored and reduce their risk by taking anticoagulant drugs. Passing abnormalities in heart rhythm are difficult to detect in many patients and it is impractical and too costly to conduct extended cardiac monitoring, even in patients who have had a stroke. The "spelling mistakes" in DNA linked with the risk were found through analysis of more than more than 300,000 common single-letter DNA changes in more than 5,000 Icelanders and were replicated in a further worldwide study of 18,000 subjects.

DNA test can help detect

(CNN) - DNA is already being used in criminal and paternity tests. But, now genetic testing offers doctors a new way to look for problems of the heart.

For years, Donna Mitchell has tried to lower her cholesterol levels through diet and exercise. Now, she is hoping a cutting-edge genetic test will give her a better picture of her risk for developing heart disease. "I want to live, I like living, I have grandchildren I want to see grow up," said Mitchell. "So, it was a no-brainer for me."

Doctors can test for millions of genetic variations for a number of diseases through a simple cheek swab and blood test. They are looking for inherited traits passed on from relatives. 

Mitchell's father died of a heart attack. While some experts say this type of testing needs more development, Mitchell saw potential benefits and so did her doctor. "If you have heart disease and you have one of these heart disease genes then the likelihood that is contributing to your problem is very high," said Dr. Robert Superko, of St. Joseph's Hospital in Atlanta. "And, if it gives you a therapeutic direction, a diet or drug to take then it becomes valuable." Mitchell's testing revealed that she would benefit from taking a cholesterol lowering statin. So in addition to sticking with a healthy diet and daily exercise, she has a new prescription for change. Mitchell tested negative for the so-called heart attack gene.