For the past several years, I have been giving more and more thought to the nature of nutrition information and discussion in America. When my dad and I first proposed the idea of authoring a book to present his scientific journey and the evidence for a plant-based diet to the public, no publisher was interested. We went through three literary agents, who all together could get only a handful of publishers to meet with us. We were repeatedly told that to make a successful book we would need to present the information in a particular way. Since we didn’t want to play by the rules, we were turned away.

Despite this discouragement, we pursued our idea. Three years later, we ended up with a giant Word document, not knowing whether anyone would publish it or whether it would even be read by more than a handful of friends. We were on the path to self-publishing when we had the good fortune of meeting a small publisher in Dallas, Texas, who saw the potential of our message.

Since the publication of The China Study, I have seen its popularity and success spiral upward by virtue of its message, without marketing or money behind its promotion. But for all the popularity among those who read the book, I have also seen name-calling and angry backlash from internet “experts” who represent themselves as scientific authorities.

Nutrition conversations usually take a turn for the worse when the focus turns to relatively minute details that are given more importance than they deserve. For example, if some correlations in the China Project don’t align with the general findings supportive of eating more plants, does it invalidate the researchers’ conclusions, the entire body of work of T. Colin Campbell, and the hundreds if not thousands of other studies supporting the health benefits of consuming plants? Of course not. But that doesn’t stop some from making this insinuation, creating confusion and camps of vocal and often angry opponents that together do nothing to further health in America. It can feel like a swamp.

How do we stay out of the swamp? We keep the big picture in mind, the wholistic approach to health. By far the most impressive aspect of the argument for eating more whole, unprocessed plants (fruits, vegetables, tubers, beans, whole grains) is the exceptional breadth and depth of evidence supporting the health effects of these foods above all other foods. There is no single study that “proves” anything; instead, we have a tapestry of studies from at least the past century representing the wholistic context of nutrition information.

We have animal experiments showing the benefits of plant-based foods or the components of plant-based foods. Some of these same animal experiments help elucidate the mechanisms by which foods affect our bodies. We have many observational studies over the past one hundred years showing numerous benefits of plant-based diets across different populations, within single populations, and within populations across time. Finally, we have a growing body of interventional research showing that the superior power of plant foods, or components of plant foods, extends even to disease treatment and reversal. Most impressively, this varied research has now demonstrated benefits for a wide range of diseases. We have seen advanced heart disease and diabetes, and their risk factors, reversed. We have seen promising interventions with rheumatoid arthritis, multiple sclerosis, and prostate cancer. We have seen evidence of benefits for kidney, bone, eye, and brain health. Anyone looking honestly at the data of the past hundred years cannot be but impressed by the overwhelming benefits of eating whole plants compared with eating other types of foods. The consistency of this story is far more impressive than any inconsistencies that may be trumpeted by various internet “experts.”

(Learn more about this research from expert researchers and health professionals.)

Of course, many details can and should be honestly disputed, discussed, and researched. As we allude to in The China Study, it is certainly not valid to say that we can make a conclusive argument that a diet must be 100 percent plants for optimal health. Most of the studies we cite in The China Study do not involve a strict plant-exclusive diet; they merely show the benefit of consuming increasing proportions of unrefined plants, or the dangers of increasing animal and processed foods.

When a patient asks me if they can have some baked fish every few days as long as they otherwise eat mostly fruits, vegetables, beans, tubers, and whole grains, I cannot honestly claim any certainty about what effect the fish will have on their health based on the available research. In the same vein, people often want to know about the amplitude of the health value or risk of specific foods—for example, what will happen if they eat one egg a day—but this level of detail will always be swampy. How can we do a study in which the effects of one single food item are separated and quantified apart from all the other diet and lifestyle factors in a person’s life, in the context of diseases that take many decades to develop? The uncertainty doesn’t stop with specific foods. Many diseases lack sufficient research on the potential benefit of any dietary change after the disease is advanced.

And that’s just diet. We also know that exercise is important. We know that our mental, emotional, and spiritual health are crucial. Depression and anxiety are very common and strongly affect diet and lifestyle behaviors. We know that sunlight and environmental factors are important. But do we know the exact details of how all these factors interact and their exact importance for each possible outcome?

You know the answer: No way!

This uncertainty is not a cause for despair or alarm. In fact, it’s good news. I, for one, want to relax, and regarding diet, we can do just that. The data is as consistent as we could ever expect it to be: Eat more whole, unrefined fruits, vegetables, legumes, tubers, and whole grains. Eat less animal foods and processed foods. It is likely that the higher the proportion of unrefined plants, the greater the benefit will be. For those with heart disease, for example, I know of only one diet that has angiographically demonstrated reversal of advanced disease, and that is a total plant-based diet without added oil, so you probably should consider that if you don’t want to ever worry about heart disease (if low-carb advocates ever produce angiographic data like this in published studies, I’ll be the first to re-evaluate my thoughts, but I pity the heart disease patients asked to participate in that trial.).

In short, we can take a few deep, quiet breaths, relax our minds and our bodies, and follow our simple dietary rules without sweating the details. We can stay out of the swamp and also turn our attention and energy to the wholistic assessment of our health, including getting exercise and sunlight and tending to our relationships and responsibilities in a way that augments our physical health and sustains mental, spiritual, and emotional health. I’ve seen enough tragedy as a doctor to know that there are no guarantees in this life, but I believe that striving for peace and relaxation in our approach can make the twists and turns more manageable.