At the end of July 2017, a startling medical story came across television and the Internet. It was a tip-of-the-iceberg story, although few people realized it at the time. There was too much background noise from the usual stream of health risks people were supposed to heed. Among the latest risks: Working more than fifty-five hours a week can be bad for your health. Pregnant women are at higher risk of not getting enough iodine.

These were not tip-of-the-iceberg stories—more like the drone of familiar advice that most people have learned to shrug off. But one item was different. Twenty-four experts on old-age dementia—the greatest health threat around the world—were asked to assess the overall chances for preventing every kind of dementia, including Alzheimer’s disease. Their conclusion, published in the prestigious British medical journal The Lancet: One-third of dementia cases can be prevented. There is currently no drug treatment to cure or prevent dementia, so this was startling news on the face of it.

What was the key to preventing dementia? Lifestyle changes, with a different focus at every stage of life. The experts singled out nine specific factors that accounted for around 35 percent of dementia cases: “To reduce the risk, factors that make a difference include getting an education (staying in school until over the age of fifteen); reducing high blood pressure, obesity, and diabetes; avoiding or treating hearing loss in mid-life; not smoking; getting physical exercise; and reducing depression and social isolation later in life.”

One item from the list was startling: staying in school until at least the age of fifteen. What in the world? A dreaded condition of old age could be reduced by doing something when you are a teenager? For that matter, it was also a little peculiar that addressing hearing loss in middle age was related to a lower risk of dementia. Something new was going on. If you looked close enough, this news story was signaling a trend in medicine that promises to be a major revolution.

Not just in dementia, but across the board researchers are drastically pushing back the timeline of disease and life-threatening disorders like hypertension, heart disease, cancer, diabetes, and even mental disorders like depression and schizophrenia. When you catch a winter cold, you notice the symptoms and realize, with annoyance, that you were exposed to the cold virus a few days earlier. The incubation period was short and invisible; only the appearance of symptoms told the tale. But lifestyle disorders aren’t like that. Their incubation period is invisible but very long—years and decades. This simple fact has become more and more critical in medical thinking. Now it looms larger perhaps than any other factor in who gets sick and who stays well.

Instead of focusing on lifestyle disorders when symptoms appear, or advising prevention when high risk has developed, doctors are probing into normal, healthy life twenty to thirty years earlier. A new vision of disease has been emerging, telling us some very good news. If you practice lifelong wellness, beginning as early as childhood, the many threats that attack us from middle age onward can be defeated—the secret is to act before any sign of threat appears.

This is known as “incremental medicine”—the iceberg of which a single story about dementia is the tip. Take the seemingly strange finding about education. Experts estimate that dementia could be reduced by 8 percent globally if kids stayed in school until they were fifteen, one of the biggest single reductions on the list. The reason why traces a long trail. The more educated you are, the more information your brain stores and the better it accesses what you’ve learned. This buildup of information, starting in childhood, leads to something neuroscientists have identified as “cognitive reserve,” a boost to the brain in terms of added connections and pathways between neurons. When you have this boost, the memory loss associated with Alzheimer’s and other forms of dementia is countered, because the brain has extra paths to follow if some grow weak or diseased. (We discuss this in more detail in our section on Alzheimer’s at the end of the book.)

As medical logic goes, long trails are changing everyone’s thinking, because they exist in many if not most diseases. Suddenly it’s not about isolated factors like not smoking, losing weight, going to the gym, and worrying about stress. It’s about a continuous style of living where self-care matters every day in every way. Not smoking, losing weight, and going to the gym still have their benefits. But lifelong wellness isn’t the same as lowering your risks for disorder A or B. Only a holistic approach will ultimately work. Wellness is no longer just a valid alternative to regular prevention. It’s the iceberg, the four-hundred-pound gorilla, and the elephant in the room rolled into one. Wellness is the great hope springing up all around us. When the public gains full knowledge of this fact, prevention will never be the same. But to grasp how radically things will change, we have to back away and examine the current situation in health care, where threat increasingly overwhelms hope.

DEEPAK CHOPRA, M.D., founder of the Chopra Foundation and cofounder of the Chopra Center for Wellbeing, is a world-renowned pioneer in integrative medicine and personal transformation. He is the author of more than 86 books translated into over 43 languages, including numerous New York Times bestsellers. Time magazine has described Dr. Chopra as “one of the top 100 heroes and icons of the century.” The WorldPost and Huffington Post global Internet survey ranked Dr. Chopra #17 of most influential thinkers in the world and “#1 in medicine.” 

DR. RUDOLPH E. TANZI, Ph.D., a New York Times bestselling author, is Professor of Neurology and holder of the Joseph P. and Rose F. Kennedy Endowed Chair in Neurology at Harvard University. He serves as the Vice-Chair of Neurology and Director of the Genetics and Aging Research Unit at Massachusetts General Hospital. Dr. Tanzi was named to TIME magazine’s TIME 100 Most Influential People” for 2015, and to the list of Harvard 100 Most Influential Alumni.

Reprinted from The Healing Self. Copyright © 2018 by Deepak Chopra and Rudolph E. Tanzi. Published by Harmony Books, an imprint of the Crown Publishing Group, a division of Penguin Random House LLC.