Clear narrowed arteries

Laughing Matter

Mother Theresa, Regis Philbin and David Bowie. When you see those three names in the same sentence, you might wonder if it’s a set up for a joke – they walk into a bar, or they’re stuck on a life raft – something like that.

But these three diverse personalities all have something in common, and it’s no joke: they’ve all undergone surgery to have stents implanted to clear narrowed arteries.

One of the risk factors for artery blockage is an elevated level of the amino acid homocysteine. In recent years, some key studies have shown that folate therapy (a combination of folic acid and vitamins B6 and B12) has been useful in lowering homocysteine levels in patients who have undergone angioplasty and stent implantation. But a new study indicates that folate therapy may actually promote blockage of the arteries.

If you’re thinking that this doesn’t make any sense – that vitamins might actually CAUSE blockage? – then you’re thinking what I’m thinking. And, I might add, I’m not buying a word of it.

Reality check

It’s headline time again. Here’s one of the outrageous headlines that covered this study: “Vitamin B May Block, Not Clear, Arteries.” And the lead paragraph of that article (found on NutraIngredients.com) was even more negative, stating that vitamin B supplements, “previously thought to help keep arteries clear after a coronary stent was inserted, actually do the opposite.”

Actually no they don’t.

A team of German and Dutch researchers recruited more than 600 subjects who had all undergone angioplasty, followed by the insertion of a stent in an artery. Subjects were divided into two groups. One group received placebo “supplements” for six months, while the rest received one intravenous dose of folic acid (the synthetic form of folate), and vitamins B6 and B12, followed by a daily regimen of oral supplements: 1.2 mg of folic acid, 48 mg of B6, and 60 IU of B12. At the beginning and the end of the six month trial period, all the subjects were evaluated with an x-ray examination of the treated arteries.

Researchers looked for a condition known as angiographic restenosis, which is the narrowing or closing of an artery that has undergone angioplasty. Nearly 35 percent of the subjects who received folate therapy showed a significant renarrowing of the arteries. That would seem to be fairly convincing evidence that folate therapy is actually a dangerous choice for patients who have had stents inserted.

The key phrase here is “would seem to be.”

The hazardous placebo

One of the primary causes of angiographic restenosis is the inflammation or scarring that is often caused by – ready for this? – the insertion of a stent. So you have to imagine that many of those who received folate treatment would have had artery renarrowing even if they’d been assigned to the placebo group. In fact, the American College of Cardiology estimates that renarrowing may occur in as much as 30 percent or more of the patients who receive a stent!

Meanwhile, nearly 27 percent of the placebo group experienced angiographic restenosis. So either a huge percentage of this group had a NEGATIVE placebo effect (extremely unlikely), or the damage done to the arteries was caused by stent insertion. That being the case, it’s a ridiculous jump to the conclusion that vitamins did the damage to the folate group. It simply defies logic.

And here’s the clincher: In three subgroups of the folate group (women, diabetics, and those with high homocysteine levels) there was no angiographic restenosis experienced at all. None.

So while the study DOES confirm that the procedure itself presents a danger of complicating the very condition it’s meant to solve, it also confirms that folate therapy may in fact help protect certain patients from angiographic restenosis.

Begging to differ

This study was reported in the New England Journal of Medicine – a source that offers enough prestige to inspire a headline writer for NutraIngredients.com to declare that B vitamins may clog arteries. Too bad he wasn’t familiar with several previous studies that showed folate therapy to be effective in preventing angiographic restenosis.

I told you about one of those studies in the e-Alert “B & E My Valentine” (9/3/02). As reported in the Journal of the American Medical Association, 533 patients who had undergone coronary angioplasty were divided into two groups. Half received a supplement of folic acid, vitamin B6 and B12, while the other half received a placebo. Six months later, the researchers found that folate treatment not only slowed the development of plaque build up in the arteries, but in some cases also prevented it from occurring.

In tomorrow’s e-Alert I’ll tell you about another recent study that reveals just how significant folate can be in support of a healthy heart.

Sources:
“Folate Therapy and In-Stent Restenosis after Coronary Stenting” Vol. 350, No. 26, 6/24/04, content.nejm.org
“Vitamin B May Block, Not Clear, Arteries” NutraIngredients.com, 6/24/04, nutraingredients.com
“ACC/AHA Guidelines for Percutaneous Coronary Intervention” Journal of the American College of Cardiology, Vol. 37, No. 8, June 2001, acc.org
“Effect of Homocysteine-Lowering Therapy With Folic Acid, Vitamin B12, and Vitamin B6 on Clinical Outcome After Percutaneous Coronary Intervention” Journal of the American Medical Association, Vol. 288, No. 8, 8/28/02, jama.ama-assn.org