Healthy Skepticism Library item: 2422

Warning: This library includes all items relevant to health product marketing that we are aware of regardless of quality. Often we do not agree with all or part of the contents.

Publication type: news

Ross E.
Vitamin B Pills May Not Stop Heart Attacks
Seattle Post-Intelligencer ( via AP ) 2005 Sep 5
http://seattlepi.nwsource.com/national/apscience_story.asp?category=1500&slug=Vitamin%20B

Keywords:
homocysteine folic acid vitamin B6 heart attacks strokes

Notes:

Ralph Faggotter’s Comments: A high serum homocysteine level is associated with an increased risk of heart attack.
Taking folic acid can reduce the level of homocysteine, therefore it seems logical to assume that taking folic acid would reduce the risk of a heart attack.
Unfortuntely this turns out not to be true.
This is an example of the fallacy of surrogate end-points.
The only way to know whether folic acid will statistically reduce the risk of heart attack is to test the proposition directly- and not jummp to any seemingly logical, but false, conclusions based on surrogate endpoints!
The triumph of this fallacy is apparent everywhere- on the internet, in newspapers, in media discussions and in everyday conversation- and it’s application has lead to the accumulation of a vast body of inaccurate opinion on every subject to which we have turned our minds.
Try studying a few advertisements for ‘medicinal products’ sold over the internet and you will see what I mean.

Full text:

By EMMA ROSS, AP Medical Writer2 hours, 46 minutes ago

Folic acid and vitamin B pills do not ward off heart attacks or strokes and may even be harmful when combined, new research suggests.

Studies showing that the vitamins lower levels of a substance in the blood suspected of playing a role in the development of heart disease have prompted hundreds of thousands of heart patients in the developed world to take them.

However, the first large study of the question, presented Monday at a meeting of the European Society of Cardiology, found that although the supplements dramatically lowered the levels of homocysteine, they offered no heart protection.

“The message is clear here: Don’t take folate or B-6 in the hope that it will stop you having a heart attack or stroke. If there was a real major effect, they would have seen it,” said Dr. Peter Weissberg, medical director of the British Heart Foundation, which was not connected with the study.

Other experts said the findings will also stir the debate over whether homocysteine has any role at all in the development of heart disease.

In the study, conducted by Dr. Kaare Harald Bonaa, a professor of cardiology at the University of Tromso in Norway, 3,749 heart attack survivors were divided into four groups. In addition to standard heart medicines, one group took high dose vitamin B pills every day for three years. Another took high dose folic acid. A third group took both pills every day and the fourth group took fake pills.

There was no difference in the groups taking fake pills, vitamin B or folic acid when it came to new heart attacks or strokes. However, there were 20 percent more heart attacks and strokes among the group that took both pills.

Those who fared worst were patients who also had kidney problems, and those who reported they also take other vitamin supplements, the study found.

“This is the latest in a series of things that when tested in a scientific way don’t actually pan out the way people expected,” said Dr. Ray Gibbons, a professor of medicine at the Mayo Clinic who was not connected with the research.

Homocysteine levels in the blood are often higher in people with heart disease. Some scientists therefore believe that lowering the substance might help prevent heart trouble. However, no study has ever shown that reducing concentrations improve heart conditions or prevent heart disease. For that reason, the role of homocysteine in the development of heart disease is hotly debated.

Folates, such as folic acid and vitamin B, are known to reduce the levels of homocysteine in the blood. That’s why hundreds of thousands of people take them, sometimes on the advice of their doctors.

“These things are very attractive to patients because they are perceived as natural, inexpensive and they are widely advertised,” said Gibbons, president-elect of the American Heart Association. “Many people have the perception that they are equivalent” to heavily researched pharmaceuticals.

“Taking something that has no beneficial effect is a bad idea, for several reasons,” Gibbons said.

It’s a waste of money, he said.

Also, it’s hard enough for heart patients to take the fistful of pills that are proven to help them and there’s a limit to how many they can tolerate taking. Adding another one only makes it less likely that they will take their real medication properly, Gibbons said.

“I’m going to purposely educate everybody I see that the folic acid they are taking has just been tested and the single large study to test it didn’t find any benefit at all,” he said. “I’m going to ask them if they are taking B-6 or a multivitamin that contains B-6 – and many of them are – and I’m going to point out that this study showed that this combination is harmful.”

Other vitamins found to be either useless or potentially harmful are vitamin E and beta-carotene, the precursor of vitamin A.