The first edition of “The China Study,” the book that helped propel plant-based eating into the mainstream, was released 12 years ago. After selling more than 2 million copies, inspiring the documentaries “Forks Over Knives” and “PlantPure Nation,” influencing dozens of cookbooks, spinning off a guide book, sparking a grassroots network of plant-based groups and launching a plant-based certification program at Cornell University, an updated edition hit bookstores just before New Year’s.

Like the first edition, this expanded edition is written by scientist T. Colin Campbell and his son Dr. Thomas M. Campbell. The book’s structure and much of its prose remain the same and its scope continues to be broad, including the research in China from which the book draws its title, along with the findings of a variety of studies – ranging from lab research and patient studies to wide-ranging epidemiological investigations – that show a strong relationship between eating mostly plants and health. The updated edition features refreshed statistics and new research that validates the original claims.

If you’ve read “The China Study” or seen the films, you know the elder Campbell spent decades at Cornell University conducting nutrition research, including his work that discovered cancer in lab animals can be turned “on” and “off” by adding or removing dairy protein from their diets, and his cancer investigation in China that found a strong link between animal-based eating and cancer (which in 1990 the New York Times called the “Grand Prix of epidemiology”). What he uncovered caused him to radically reassess what he and his family were eating and ultimately to write “The China Study” and the 2014 bestseller “Whole: Rethinking the Science of Nutrition.”

The younger Campbell co-wrote the initial book. In the time since, he completed his medical studies and was appointed director of a plant-based medical practice called the Program for Nutrition in Medicine at the University of Rochester in upstate New York.

The hardcover edition of “The China Study” has gone through 21 print runs, and the paperback has been printed 45 times, according to Jennifer Canzoneri, marketing director at Dallas-based publisher BenBella Books.

Canzoneri said the book was not an overnight best-seller. Rather it picked up speed over the years. In those same years, the elder Campbell lectured widely, including in Portland in 2011 at the annual banquet of Mercy Hospital’s attending physicians. The book was well-known in health food circles by then, and later that same year the airwaves were filled with reports of former President Bill Clinton’s adoption of a vegan diet to reverse his heart disease. He often mentioned “The China Study” in interviews.

“The success of the book took us a little by surprise,” Thomas Campbell told me by phone from his office in Rochester.

He recalled being rejected by a number of publishers before BenBella decided to take a chance on the manuscript. BenBella publishes a full catalog of vegan and vegetarian books.

In 2005, the book didn’t really fit into an existing market category, Campbell said. Diet books were on store shelves, he said, but no books that offered science-based nutrition research.

BenBella Publisher Glenn Yeffeth said when he first read the manuscript he was “immediately captivated.”

“The book was very compelling, and the abundance of scientific studies supporting their conclusions was a feature, not a bug,” Yeffeth said. “I think most readers are tired of diet books based on opinion rather than established science.”

“The China Study” not only sells well, but it, and the related films, have led to dozens of cookbooks. (Neither Thomas Campbell nor T. Colin Campbell have a financial stake in the films or the cookbooks, although they have written forewords for some of the books.)

These days, it’s become something of a family affair: Nelson Campbell (also T. Colin’s son) produced the “PlantPure Nation” film and his wife, Kim Campbell, wrote “The PlantPure Nation Cookbook,” published in 2015, and “The PlantPure Kitchen,” released last month.

BenBella will release “The China Study Family Cookbook” this spring, which is written by Deb Sroufe and edited by LeAnne Campbell, T. Colin’s daughter. Her other related cookbooks include “The China Study Cookbook,” “The China Study All-Star Collection” and “The China Study Quick & Easy Cookbook.”

The current Amazon top 20 list of best-sellers in the vegetarian category contains eight books related to “The China Study” or the two films.

Thomas Campbell told me in addition to writing “The China Study Solution” in 2015, he has used the research to create a medical practice that dispenses plant-based meals in place of pills. Campbell and his colleagues offer consultations to people with a range of conditions, from diabetes to cancer.

Patients supply their goals, and Campbell helps them generate a plan. He also offers a seven-day intensive program, complete with cooking classes, at a nearby spa; and an eight-week intensive program.

Campbell and his father both know the University of Rochester practice is an outlier and that most hospitals have a long way to go before doctors know how to use diet as medicine; societal resistance to the scientific evidence they present for plant-based eating is among the book’s themes.

In the updated chapter on heart disease, as in the rest of the book, the acronym WFPB appears often and stands for whole-foods, plant-based. The Campbells write that, since the first edition was published, “there has been virtually no serious discussion in the cardiology community about the possible use of dietary interventions” even though “a WFPB diet can prevent and treat heart disease.”

Meanwhile, the evidence that this approach works continues to build. This is clear in the revised edition, where statistics have been updated and new medical research added.

For instance, the updated edition includes information on the recent prostate cancer work of Dr. Dean Ornish. Known for his work reversing heart disease using a plant-based diet, Ornish conducted a randomized trial of 93 men with elevated PSA scores (a marker of the slow-growing disease) who chose to monitor the progression of the disease rather than seek traditional treatments. Ornish divided the men into two groups, with one group prescribed a plant-based diet and stress reduction and the other group prescribed the standard “watchful waiting” care. The study was published in 2005 in the Journal of Urology, and has been updated many times since then.

The Campbells write that after one year, the vegan group saw a decline in their PSA scores compared to the traditional group. Even more remarkable, only 5 percent of the dietary change group needed conventional cancer treatment after two years compared to 27 percent of the men who were in the standard care group.

The Campbells write: “Every doctor should tell every man with prostate cancer to stop consuming dairy immediately and embrace a WFPB diet.”

Another new section reviews the evidence that has accumulated in the past decade linking meat and dairy-heavy diets to diseases of the mind, including Alzheimer’s. “Memory loss, disorientation, and confusion are not inevitable parts of aging, but problems linked to that all important lifestyle factor: diet,” the Campbells write in the updated book.

The last section of the book provides an overview of the cultural, corporate and institutional barriers standing in the way of more people learning that common diseases can be prevented and reversed by eating a diet centered on whole plant foods.

The barriers, Thomas Campbell told me, are beginning to crack. He cited the increasing number of research-heavy books about plant-based diets and increasing attendance at national plant-based medical conferences. Campbell also mentioned subtle but important shifts in institutional language.

“If you look at the executive summary in the recent dietary guidelines, the term plant-based was used all over,” Campbell said. “That would have never occurred 10 years ago.”

I’ll be curious to see where the next 10 years bring us now that this expanded edition of “The China Study” is on the market.

Avery Yale Kamila is a freelance food writer who lives in Portland. She can be reached at

avery.kamila@gmail.com

Twitter: AveryYaleKamila