Expert Consensus

The problem isn't access to medical care. According to an estimate by the Mayo Clinic, nearly 70 percent of Americans receive prescription medications. The problem is that these trillions in health care spending are not targeting the causes. The greatest risk factor for death in the United States is what we eat. It's the food. The standard American diet isn't to die for — it's just to die from. Literally. We eat as if there were no tomorrow. There are even data to support that, from a study titled “Dining on Death Row,“ which I describe at see.nf/usa. The result is that there is no major difference between what death row inmates request as their last meal and what Americans typically eat. If we keep eating as if we have our execution meal ahead of us, sooner or later it will be.

Expert Consensus

On the other hand, there is also good news: The potential for correction is enormous. One of the most beautiful graphs in all of public health is the curve of deaths from lung cancer. It took decades for us to finally turn the corner, but as smoking rates fell, the number of lung cancer deaths plummeted, too. I look forward to the day we see the same thing with diet.

Yes, about 80 percent of chronic diseases and premature deaths could be prevented if people didn't smoke, were physically active, and ate a “healthy diet“ — but what does healthy eating actually mean? Unfortunately, what we hear in the media about nutrition is often contradictory and confusing. In today's fiercely competitive media marketplace, many journalists are under pressure to produce sensations. Media analysts have suggested there may be deliberate incentives to take facts out of context in order to sell more newspapers. (This analysis was published before the practice of clickbait headlines, which presumably makes everything even worse.)

There is a quote from the 1940s by a leading expert in the field that today, more than 75 years later, seems more relevant than ever: “It is regrettable that the subject of nutrition seems to have a peculiar attraction for the gullible, the social zealot and, in the commercial field, the unscrupulous — [a combination] which can drive the sober, objective scientist to despair.”

The most important problem in preventive health we face may be our misguided lifestyle choices based on misinformation. The way recommendations for healthy eating are overshadowed by industry interests, ideologues, and misguided media reminds me of how some deny climate change. What we need is a kind of IPCC for nutrition, and I am proud to have contributed to such an initiative. The True Health Initiative is a nonprofit organization with hundreds of experts from dozens of countries who have agreed on the principles of a healthy lifestyle that “combat false facts and false doubts with time-tested, evidence-based principles of lifestyle as medicine, to create a world without preventable disease.” Spoiler alert: The healthiest diet consists mainly of minimally processed plants.

As Nature Intended

Perhaps this is not surprising, since it is what we ate from the evolutionary split from our last common primate ancestor about 20 million years ago until we began making tools about two million years ago. We know that for the first 90 percent of our development, when our nutrient needs and digestive metabolism took shape, we ate what the other great apes still eat today, namely primarily whole plant foods. Even the apes that eat the most meat — chimpanzees — get more than 98 percent of their diet from plants. You can give a natural omnivore like a dog the cholesterol equivalent of 500 eggs, and he just wags his tail, whereas a fraction of that amount can clog the arteries of an herbivore within a few months. Some animals are used to eating excess cholesterol and getting rid of it. Our bodies can't handle it, as shown by the fact that coronary heart disease is our leading cause of death.

In the Stone Age there was little selection pressure to protect people from their escalating diets, because most did not live long enough to have a heart attack. If average life expectancy is 25 years, the genes of those who somehow survive to reproductive age will be passed on — and that means, up to that point, not starving to death. The more calories, the better. A Stone Age human who ate a lot of bone marrow and brains — whether human or not — had a selective advantage (kind of like finding a time machine with a supply of Twinkies). If we only have to live long enough for our children to reach puberty and pass our genes on, we don't need protection against the devastating consequences of chronic disease.

To find a population that is nearly free of chronic disease in old age, we don't have to go back millions of years. As I describe in detail in How Not to Die, in the 20th century there was virtually no coronary heart disease in mission hospitals in rural Africa, and the same was true for other leading causes of death such as high blood pressure, stroke, diabetes, and common cancers. In a sense, people in rural China and Africa ate the way we ate for more than 90 percent of the past 20 million years, namely almost exclusively plant-based. But how do we know it was the diet and not something else? From the groundbreaking research of Pritikin, Ornish, and Esselstyn, who showed that plant-based diets can halt or even reverse the progression of heart disease in most patients when formally studied. In fact, this is the only type of diet that has ever done that.

Are a healthy diet and a healthy lifestyle all you need to fight the ravages of aging? If that were the case, this book would have been much thinner. As you have read in these pages, there is a wealth of pills and treatments and creams, supplements, and certain foods that help smooth wrinkles, grow hair, shrink the prostate, and improve vision, teeth, erection, cognition, and much more. But the foundation is diet and lifestyle — and that's good, because you control it.