I’ve been a vegetarian for 10 years, and in that time my family has come to accept and embrace my dietary choices. In turn, I’ve never tried to persuade them to reduce their meat intake. We’ve had a household policy of live and let live.

Last week I watched a documentary that changed my opinion about that. In Forks Over Knives (2011), director Lee Fulkerson examines the link between animal protein consumption and chronic illness in America. His film summarizes the life’s work of T. Colin Campbell, Ph.D. and Dr. Caldwell Esselstyn, distinguished researchers in nutrition and medicine, and, over two hours, chronicles the director’s own decision to switch to a vegetarian diet. He does this to combat dangerously high cholesterol and heart inflammation.

The film is well organized and precise, convincingly building the case for how overburdened America’s healthcare system is. Heart disease and cancer kill hundreds of thousands every year; yet, Lee argues, modern medicine treats only symptoms. Bypasses and chemotherapy do nothing to address the root causes of those chronic diseases which impact so many.

Preventing cancer and heart disease is, according to Campbell and Esselstyn, simple: people have to remove animal protein from their diets. Entirely. This recommendation follows Campbell’s massive 6,000 person nutritional study in China, and the book he wrote about it, The China Study; as well as Esselstyn’s 20-year clinical trial with 18 terminally ill patients, each told they had less than a year to live. (All 18 eliminated animal protein from their diets, overnight, and all but four are still alive today.)

I wouldn’t lightly advise anyone to change their diet, but after watching this film and reading up extensively on the research behind it, I’m mailing a copy to each member of my family. I do, after all, want them to live as long as possible.

Consider your diet and reducing how much animal protein you eat. And watch this film. I want to know your thoughts about it.