Dr. Kim Williams thought he followed a heart-healthy diet: He avoided red meat and fried foods. He ate his chicken breast without the skin.
But in 2003, the Chicago cardiologist realized his level of LDL, the so-called "bad" cholesterol, was too high. Inspired by a patient's success with a plant-based diet, Williams began using "meat substitutes" for protein. Within six weeks, he says, his LDL level plummeted almost by half into the healthy range.
Now a firm believer in the vegan way of eating — no meat, fish, eggs or dairy — Williams is about to step into a prominent leadership role as president of the American College of Cardiology. When he wrote an essay on the benefits of a plant-based diet for cardiac patients, it kicked off yet another rancorous debate over how people should eat to best protect their hearts.
Supporters praised Williams, chief of the cardiology division at Rush University Medical Center, for highlighting the widely accepted health benefits of eating fruits and vegetables. Critics grumbled about the "food police" and questioned whether a physician with such an influential position should be advocating for a diet that many view as extreme.
"Doctors who recommend a vegan diet are experimenting on their patients," said Dr. Jack Wolfson, an Arizona cardiologist who encourages "Paleo" nutrition, or eating unprocessed foods that can be hunted or gathered, including meat.
Williams says he's surprised by the polarized reaction and dismisses the idea that veganism is "experimental" given the considerable data gathered on people who eat that way. But he's also eager for large-scale, randomized trials and acknowledges there are many ways to eat more healthfully.
"Anything someone does to move away from the Standard American Diet will make a huge difference in terms of diabetes, hypertension, obesity and heart disease," said Williams, referring to the nation's high consumption of sugar, saturated fat and processed foods.
"Given the health implications of diet, putting the issue in front of people who live with an epidemic of heart disease is not a bad thing," he added.
The debate underscores the personal and complex nature of nutrition science. Though fruits and vegetables are part of any healthy diet, there's no consensus on the best way to eat, causing endless confusion and frustration for consumers.
Williams' statements in support of a plant-based diet — an option naturally low in saturated fat — came not long after a study published in March famously challenged the conventional wisdom that people who consume more saturated fat are at higher risk of heart disease.
Vegan products are easier than ever to find in stores and restaurants, reflecting the diet's increasing popularity. But another trendy choice is the high-protein, high-fiber Paleo or "caveman" diet, which includes grass-produced meats and seafood and excludes grains, potatoes and legumes.
Among those who choose a plant-based diet, many cite health reasons, but environmental and ethical concerns are more important for others.
Vegans eat no animal products — including meat, fish, eggs, dairy and, often, honey. But though Williams eats like a vegan, he doesn't describe himself that way because of the term's other connotations. Many vegans avoid all animal-based products, including leather, fur, silk, wool and some soaps and cosmetics, for ideological reasons.
"It just happens that my view on a plant-based diet agrees with those groups," Williams said. "For me, it's a health and diet statement."
Vegetarians generally abstain from eating animal flesh of any kind. Dairy is usually OK, and some eat eggs. Pescetarians are vegetarians who also eat fish and seafood. The term flexitarian refers to people who primarily eat plant-based foods but might indulge when they smell bacon.
Well-planned vegetarian diets, including vegan ones, are nutritionally adequate and appropriate for nearly everyone, including pregnant women and elite athletes, according to the Academy of Nutrition and Dietetics. The National Institutes of Health says a varied vegetarian diet can reduce the risk of obesity, heart disease and Type 2 diabetes, as well as lower blood pressure.
But experts also say vegans and vegetarians who aren't careful can wind up consuming a high-carbohydrate diet lacking in basic nutrients.
"You can eat white bread and Oreos, a bunch of Boca Burgers, and a gallon of sweetened soy milk and be 'vegan,'" Dr. Ashwani Garg wrote in response to Williams' essay on MedPage Today.
Garg, a family medicine practitioner in Hoffman Estates, said in an interview that he commends Williams for raising the issue of nutrition but would rather see him promoting plant-based nonprocessed foods in general.
Cardiologist Neil Stone, medical director of the vascular disease center at Northwestern Medicine's Bluhm Cardiovascular Institute, said the vegan diet hasn't been conclusively shown to be better than other healthful eating patterns, including the DASH diet and the Mediterranean-style diet. Both emphasize fruits, vegetables, nuts, beans and seeds, but they differ in the amount of recommended fats.
Vegetables are also the foundation of Paleo nutrition, "but everyone should be eating some amount of meat and/or seafood on a weekly basis," Wolfson said. "I'm talking about free-range, grass-fed, healthy animals," he added. "I'd never tell anyone to eat a burger with a bun."
Wolfson, who sells duck, pork and beef fat in his office to be used for cooking, points to research that has challenged the relationship between saturated fat and heart disease. But the question is far from settled.
In general, eating foods that contain saturated fats raises the level of cholesterol in the blood, and high levels of LDL cholesterol increase the risk of heart disease and stroke. But the impact can vary by individual. For some people, the cholesterol consumed in food has a greater impact on their blood cholesterol.
In addition, researchers tend to study isolated nutrients, but the foods we eat are more complex.
"I don't recommend focusing on any single nutrient -- including fat,” said Dr. Stephen Devries, executive director of the Gaples Institute for Integrative Cardiology, a nonprofit that advocates for a greater role of nutrition in health care. “For example, cutting down on saturated fat but replacing it with sugar, leaves you no further ahead."
In March, the journal Annals of Internal Medicine published a review of current literature that concluded the current evidence does not support the idea that consuming less saturated fat will prevent heart disease. Many experts quickly responded that people shouldn't see the paper as a green light to eat all the steak and butter they'd like.
One complicating factor is that when people cut down on fats they tend to replace them with other foods that are bad for cardiovascular health, such as processed carbohydrates.
"It's not that saturated fats are good," Stone said. "It's what the saturated fat is replaced with that's the problem. That's what has confused America."
Current guidelines from the American Heart Association restrict the consumption of saturated fats to about 6 percent of daily calories and encourage people to eat polyunsaturated fats, such as omega 3 and omega 6, to prevent heart disease. For someone eating 2,000 calories a day, that's about 13 grams of saturated fat.
Williams' conversion to vegan eating began in 2003 after a nuclear scan on a patient with severe heart disease showed startling improvement after she had followed a plant-based diet for six months while also exercising and meditating. He was surprised but later discovered several published studies documenting similar improvement.
Around the same time, he discovered his own cholesterol was 170 milligrams per deciliter, well above the normal range of 70 to 130 mg/dl.
Williams searched the Internet and discovered that he was eating more cholesterol than he realized. He changed to a cholesterol-free diet, consuming protein in the form of vegetable-based meat substitutes and nuts. "Within six weeks my LDL cholesterol level was down to 90," he wrote.
Now Williams discusses the benefits of a plant-based diet with patients who have high cholesterol, diabetes, hypertension or heart disease. He may encourage those patients to seek out and sample plant-based versions of basic foods such as chicken or eggs, or he'll search for alternatives and email suggestions.
At the same time, Williams recognizes that guidelines from the American College of Cardiology and the American Heart Association don't specifically recommend a vegan diet because the studies on its effects aren't definitive.
Like his colleagues, he hopes for large, well-designed randomized trials rather than polls, opinions and analyses of observational data. But until then he's sticking to vegetable-based protein.
"The day that there is similar data on the dangers of processed soy as there is on processed meat, I will drop it like a hot potato, or perhaps just eat the potato," Williams wrote in defense of his essay.