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.
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.
Nutrition education is also slighted during fellowship training, the period after medical school when doctors specialize, said integrative preventive cardiologist Stephen Devries, executive director of the Gaples Institute for Integrative Cardiology in Deerfield, which advocates for nutrition and lifestyle interventions.
In the 32-page cardiology accreditation guidelines, "nutrition isn't mentioned once," said Devries, who is gathering support to lobby the Accreditation Council of Graduate Medical Education to mandate nutrition education as part of all physician training programs.
Today's primary care physicians spend less time than previous generations of doctors talking to patients about what they eat, according to a study published last year in the journal Medical Care.
Among the obstacles? "Many physicians are overweight themselves and may feel uncomfortable talking about healthy diet and physical activity when they themselves struggle with similar issues," said lead author Jennifer Kraschnewski, an assistant professor of medicine and public health sciences at the Penn State College of Medicine.
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 olive oil, fruits, nuts, vegetables and cereals, moderate amounts of fish and poultry and low doses of dairy products, red and processed meat, and sweets. Consuming wine at meals in moderation, exercise and relaxing with friends are also considered important elements.
The heart-healthy mechanism is still a mystery, but 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."
"Certain foods compromise and injure the endothelial cells' capacity to make nitric oxide," Esselstyn said. "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, who also, controversially, tells his patients to avoid oil.
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.
Yancy stressed that the results went beyond added olive oil, nuts or even regular wine consumption. "They were greatly influenced by diet coaching and constant reinforcement that kept patients on board with the chosen diet," he said. "It's the entire diet program. That's where the real gains reside."
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 Devries, 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. "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."
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