Despite a growing consensus that cardiovascular disease is a "food-borne" illness, many physicians are ill-prepared to advise patients on what they should eat to best protect them from heart attack or stroke.
One provocative new study found that a Mediterranean-style diet was so effective at warding off heart attacks, stroke and death that scientists stopped it early. They wanted to let subjects in the control group and the public start to reap the benefits.
Yet the number of hours devoted to nutrition education in medical schools is decreasing, leaving doctors unequipped to deal with common patient concerns about diet, studies have found.
Even as rates of obesity and Type 2 diabetes soar, researchers report that doctors are spending less time than ever talking to patients about nutrition because they lack time, training and optimism that patients can make lifestyle changes. Insurance is also more likely to cover procedures than behavioral counseling.
"Ask 50 cardiologists and they'll say, 'Of course I know about the Mediterranean diet,'" said Dr. Dean Ornish, president and founder of the nonprofit Preventive Medicine Research Institute. "But if you ask, 'Do you teach it?' they say, 'No, who has the time?' This is real-world medicine. We need to do it better."
"There's tremendous ignorance about nutrition among physicians," added Dr. William Davis, a preventive cardiologist in Milwaukee. "It has never been part of the culture."
Cardiovascular disease, which kills 600,000 Americans a year — more than all types of cancer and AIDS combined — is linked to high blood cholesterol. Though cholesterol-lowering statin drugs are popular treatments, levels in the body also can be lowered through diet.
Meanwhile, lifestyle changes have been shown to work better than medication in preventing obesity and Type 2 diabetes, both risk factors for heart disease.
Procedures involving stents and angioplasty can save lives when patients are in the middle of a heart attack or having unstable symptoms, but patients also often undergo them in more stable situations where they have not been proved to prevent a heart attack or extend life.
Research suggests that physicians don't feel comfortable, confident or adequately prepared to give nutrition advice, said Kelly Adams, a research associate in the department of nutrition at the University of North Carolina.
One survey published in 2003, for example, found that 96 percent of internists and 84 percent of the cardiologists who responded did not know that a low-fat diet, in general, would increase triglycerides in the blood. High triglycerides increase the risk of heart disease.
"This can lead to well-meaning but misguided information being given to patients," Adams said.
Some heart specialists say the question is whether physicians should be the ones supplying the information on diet and nutrition, even if they are well-educated.
"The patients we see are in sensory overload — a new diagnosis, an evaluation of lifestyle, new medicines, perhaps recent procedures and then diet issues," said Dr. Clyde Yancy, chief of cardiology at Northwestern University's Feinberg School of Medicine.
What patients need most is coaching and support that can help them make lasting behavioral changes, but that's no easy task, Yancy said. "We (physicians) may lead the team, but it does take a village and requires having access to good information and an expert dietitian," he said.
A 1985 landmark report on nutrition in medical schools by the National Academy of Sciences found that on average, future physicians received 21 hours of nutrition instruction over four years. Medical students need at least 25 hours to be adequately prepared to help patients, the report concluded.
Since then, professional groups, federal agencies, scientific journals and even a congressional mandate have called for improved nutritional training among doctors.
Yet more than two decades later, nutrition education in U.S. medical schools remains inadequate, according to a 2010 study led by Adams and her UNC colleagues and published in the journal Academic Medicine.
On average, doctors receive 19 hours of total nutrition education in medical school; in 2004 the average was 22.3 hours, according to the study, conducted as part of the Nutrition in Medicine project at UNC. In 2009, 27 percent of the schools met the minimum standard of nutrition training, compared with 38 percent in 2004.
Ben Kester, 25, who is finishing his second year at the Northwestern medical school, said nutrition has been mixed into some of his classes; in a recent cardiology unit, the class talked about using statin drugs in combination with diet as the first line of treatment, he said.