by Kristin Ohlson

Based upon what he observed at a plantation in Hawaii on his first job out of medical school, California physician John McDougall has eaten a vegan diet for 35 years. There, he cared for workers hailing from China, Japan, Korea and the Philippines, and quickly noticed that first-generation immigrants didn’t have the diseases he’d been trained to treat: no heart disease, no diabetes, no cancer, no arthritis. However, he saw more evidence of these conditions with each succeeding generation, as the workers increasingly indulged in standard American fare.

“My first-generation patients kept to the diet they had eaten in their home countries,” McDougall says. “They lived on rice and vegetables, with very little meat and no dairy. But, as their kids started to eat burgers and shakes, the kids got fatter and sicker.”

Accounts like this contribute to the fact that today, as many as 8 million Americans say that they are vegetarians, according to a 2009 Harris Interactive survey commissioned by The Vegetarian Resource Group. Of these, about a third are vegans, who avoid meat, eggs and dairy products, as well as meat. Many choose a plant-based diet for better health; others, because they believe it’s more humane and environmentally conscious. According to the Natural Marketing Institute, as many as 30 percent of Americans say they are trying to reduce their meat intake.

Vegan advocates, who include celebrities like Alicia Silverstone, Tobey Maguire and Woody Harrelson, support a robust vegan infrastructure, with new cookbooks and gourmet recipes, hip new restaurants and an explosion of websites and chat rooms devoted to a plant-based lifestyle.

Some omnivores doubt that people can be either healthy or satisfied without the nutrients and flavor of animal products. After all, didn’t we evolve from meat eaters? Yes, our hunter-gatherer forbears may have liked meat, explain some experts, but it comprised only a tiny part of their diet—those animals were hard to catch. Instead, early humans subsisted largely on wild vegetables, fruits, nuts and seeds. Milk and cheese didn’t become a diet staple until 10,000 years ago, and then only in Europe.

Author Virginia Messina, a registered dietitian with a master’s degree in public health, based in Port Townsend, Washington, says her research for the American Dietetic Association confirms that vegetarians overall have lower levels of bad cholesterol, less obesity and a lower incidence of both hypertension and colon cancer than meat-eaters. Vegans have even lower cholesterol and blood pressure than vegetarians who eat eggs and dairy.

But eschewing animal products only leads to improved health if people follow some basic guidelines. Vegans must be sure to eat a variety of whole grains, beans, legumes, nuts and seeds—good sources of protein—as well as fruits and vegetables. (Messina notes that the average person needs about 55 grams of protein a day, about half that ingested in a typical America diet.) And, while plant diets are generally rich in iron, Messina notes that vegans need to make sure that the iron is well absorbed by eating a diet rich in vitamin C—leafy greens, as well as citrus, peppers, potatoes, melons and tomatoes. She reminds vegans to get enough zinc in their diets with nuts, seeds and seed butters like tahini. Some nutritionists suggest that vegans take a vitamin B12 supplement, as well as a calcium supplement.

Vegans insist that giving up these animal products doesn’t mean giving up the pleasures of food. Perhaps no vegan chef has done more to convince skeptics than Isa Chandra Moskowitz, with cookbooks like Vegan with a Vengeance, Veganomicon, and Vegan Cupcakes Take Over the World. (She also founded the Post Punk Kitchen vegan website with free recipes at theppk.com). Many of her recipes take fewer than 45 minutes to prepare, often from inexpensive ingredients. “It’s an economical way to eat,” she says. “It’s the way poor people have always eaten.”

Certainly, it takes some retraining to adopt a vegan diet. Some people start by keeping meat portions to three or four ounces and going meatless one day each week, as author Michael Pollan recommends. But once people get the hang of preparing tasty, plant-based meals, they realize the breadth of the culinary experience.

“The people who have been vegan for any length of time actually have a diet that’s substantially more diverse and interesting than the typical omnivore,” observes Erik Marcus, author of The Ultimate Vegan Guide: Compassionate Living Without Sacrifice. “You might think that your diet becomes more limited if you get rid of animal foods, but the opposite is actually true.”

Kristin Ohlson is a freelance writer in Cleveland, OH. Reach her at KristinOhlson.com.