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.
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.
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.
Learning about nutrition is important, he agreed, but it can also fall by the wayside amid other demands. Medical school can be so stressful that, often, "our own eating habits are the first thing to go," he said.
Though several diets can benefit heart health, a systematic review ranked the Mediterranean diet as the most likely model to provide protection against heart disease. The Lyon Diet Heart Study previously showed that it could reduce the risk of a second heart attack by up to 70 percent.
The traditional Mediterranean-style diet is characterized by high intake of fruits, vegetables and grains, moderate amounts of nuts, seeds, olive oil, fish and poultry and low doses of dairy products, red and processed meat, and sweets. Exercise and relaxing with friends are also considered important elements.
Evidence suggests the diet is anti-inflammatory and helps improve the function of endothelial cells, which pump out nitric oxide.
"Nitric oxide keeps cells within our blood vessels flowing smoothly, prevents inflammation from developing in the walls of the arteries, keeps us from getting stiff vessels and has a role in keeping us from developing blockages or plaque," said Dr. Caldwell B. Esselstyn Jr., author of "Prevent and Reverse Heart Disease," a former Cleveland Clinic heart surgeon who says the Mediterranean Diet is not as healthful as proponents claim. Esselstyn recommends a diet completely free of animal products, with minimal use of added oils.
"Certain foods compromise and injure the endothelial cells' capacity to make nitric oxide," said Esselstyn, whose nutritional approach was highlighted in the documentary "Forks Over Knives."
"As we are constantly getting less and less nitric oxide, we are less able to prevent coronary artery disease."
Animal products, processed foods and sugar compromise the cells the most, said Esselstyn.
For the recent study on the Mediterranean-style diet, published last month in the New England Journal of Medicine, researchers in Spain randomly divided patients who were already at high risk for heart disease into three groups. One was given a low-fat diet and advice on how to follow it.
The other two groups were placed on a Mediterranean diet, with one using at least four tablespoons of extra-virgin olive oil per day for cooking and dressing food. The third group was told to eat an ounce, or a generous handful, of a combination of walnuts, almonds and hazelnuts per day.
The volunteers in both Mediterranean diet groups had a "substantial reduction in the risk of major cardiovascular events among high-risk persons," the researchers concluded.
For Jessie Chavez, 39, a software engineer for Google, heart disease loomed in his future. His father had three heart attacks — the third was fatal — and Chavez, who worked long hours at the computer and neglected his diet, had high cholesterol.
Initially his doctor put him on a statin drug. But when he asked if there was anything more he could do, "she said, 'Well, of course you can look into diet,' but I felt like she didn't see it as something viable," Chavez said.
Chavez went to see a another doctor who incorporated a Mediterranean-style diet and exercise into his heart health program. Chavez, 5 feet 10 inches tall, dropped his weight from 196 to 156 and is now off nearly all medication because his cholesterol is back to normal. Once physically unfit, he's now able to run 10 miles.
"As an engineer, I always think, 'Where's the proof?' " said Chavez, of Berwyn, Ill. "To actually have a cardiologist tell you, 'Here are a few studies; this is what it shows and this is the impact' gives you more options. I liked knowing it wasn't part of a fad, but science."