The woman had sudden, squeezing chest pains that traveled to her arm. An intensive care nurse and the daughter of a heart patient, she knew the stakes. She informed her supervisor, summoned the elevator, and came directly to the ER, where she described her symptoms to me with seasoned calm.
Six hours later, tests in hand, we were both relieved. Her pain was gone and, thankfully, it wasn't a heart attack. But the residue of fear lingered, and like many who experience a "near miss," she wanted an action plan. "What about that new diet?"
She was referring to the Mediterranean Diet which, it turns out, isn't new at all. Nearly two decades ago studies showed that heart patients who ate a Mediterranean Diet saw life-saving benefits. So what was different about this year's trial? The subjects. Healthy men and women without heart problems, like my ICU nurse.
It is a strange paradox that trials to prevent heart problems are usually performed on people who already have them. Why? Math. There is, simply put, a lot more room for improvement in a sick heart than a healthy one. For those with heart disease, events like strokes and heart attacks will happen occasionally. As unfortunate as this is, it gives researchers something to prevent. So researchers can easily study treatments for heart patients. But the chance that a healthy nurse will suffer a heart attack or stroke is tiny -- less than 1 percent, and almost zero. It's tough to prevent something rare, and this is why it would take thousands of subjects followed for many years to demonstrate preventive heart effects in healthy people.
Enter: the Mediterranean Diet study, published in April of this year, with more than 7,000 healthy people followed for an average of five years. These numbers are unusual, and they were big enough to show convincingly that fewer heart problems (strokes, heart attacks, deaths) occurred in those eating a Mediterranean diet than those on a low fat diet. This twist -- using the diet to prevent first-time heart problems -- extends the diet to healthy people for the first time. And that includes my ICU nurse.
I recommended she start the diet, since it seems less like a "diet" to me and more like a vacation on the Riviera. She was game. But she had another question: Her cholesterol levels were high at her last doctor visit, and though her doctor had suggested statin drugs, she demurred. (Nurses, like doctors, are famously disagreeable patients.) But now, she wasn't so sure.
Like the Mediterranean Diet, the statins have been studied in healthy people and in heart patients. In heart patients the benefits seem to trump the harms for many. But in healthy folks, again, it's tricky. In one large review the drugs reduced heart attacks and strokes by 25 percent, which is almost as good as the 30 percent reduction from a Mediterranean Diet. But there is still debate. How much? Lots. In an issue of the Journal of the American Medical Association last year prominent cardiologists took opposing views on the subject.
Now, this is confusing: Statins worked almost as well as the Mediterranean Diet, so why would experts everywhere embrace one but argue about the other? According to cardiologist Dr. Rita Redberg, the editor-in-chief of JAMA-Internal Medicine and author of the "con" view, the reason is simple: When it comes to drug therapy there is no free lunch. Some people experience benefits -- but some experience harms. Muscle damage, liver problems, and diabetes can all occur with statins. Ultimately, Redberg's logic is the same as the Diet researchers': Healthy hearts rarely have problems, which means harms can become more likely than benefits. In other words, taking a statin means hoping for a free lunch -- no side effects.
In this view if you're a winner, your heart problem is prevented by a statin. Problem is, that's rare because having a heart problem to prevent is rare. And if you're a loser, you get diabetes. This is uncommon too, but might still be more common than a heart problem. It's a roll of the dice, and statin supporters think that more people are winners than losers. Skeptics say the reverse.
Of course, the debate highlights what's unusual about a Mediterranean Diet: It's a free lunch. No losers, just rare winners. Among proven heart therapies, that is unique. And the bonus? It's more effective than statins. Dr. Redberg told me: "If the Mediterranean diet was a pill, it would be a blockbuster."
For my ICU nurse, still healthy, and still concerned, I recommended she skip the statins and start the Diet. She agreed. We figure she's better off eating a healthy lunch than hoping for a free one.