Cancer is often described as though it is an arbitrary disease that can strike anyone at any time. Just random bad luck. What often accompanies this sense of randomness is a sense of predestination, as though once a person is diagnosed with cancer, there is little he can do to alter the course of fate.

But that’s simply not true. Cancer does not grow in isolation. It develops within an environment we help create by the things we eat day after day, by our stress levels, our physical activity, our support network, the quality of our sleep, and our exposure to environmental toxins.

We now know that making these six lifestyle changes — what we call the “mix of six”—could prevent at least 50 percent of the most common cancers. But it seems that knowing is not enough.

As someone who has devoted most of my adult life to cancer research, I’ve long known exactly the kind of lifestyle I need to live to cultivate a body that is inhospitable to cancer growth and to prevent cancer from forming. But just knowing this wasn’t enough. In March, as my wife Alison and I were finishing up the final draft of our book “Anticancer Living,” I was diagnosed with advanced melanoma.

The irony of getting cancer after studying and co-authoring a book on cancer prevention is not lost on me. Over the last 10 years, I have tried to follow the tenets of anticancer living and embracing the “mix of six.” But effectively managing stress in my life, fostering calm, and getting enough sleep have been a challenge. I am passionately devoted to my career, and I have often driven myself far beyond what was healthy for my body. Studies have shown us that while diet and exercise are important, managing stress and healthy sleep habits are crucial. For example, chronic stress and sleep deprivation modify how food is processed and influence our food choices and energy for exercise. Stress and sleep deprivation make us more susceptible to developing cancer by reducing immune surveillance and increasing inflammation, among many other biological processes within the tumor microenvironment that allow cells to grow out of control. Our immune system plays a major role in fighting the development of cancer, and I’m sure that my chronic lack of sleep and high stress levels were far from optimum for my immune system.

Having cancer has put the necessity of following the lifestyle prescription in a different light. It has given me the permission to take care of myself in a way that I had never done before. I now prioritize exercise and my mind-body practice daily, something that I did not consistently do before. Although this extra focus on self care does take time, I have gotten more efficient with my remaining work time and get more done then before. I focus on one task at a time and time-block my whole day. I also healthfully multitask some behaviors, like having a recumbent bike under my standing desk and engaging in walking meetings. I can honestly say that I have never felt healthier: physically, mentally and spiritually.

Since going public with my diagnosis, everyone in my community has been supportive. A common phrase I’ve heard from friends and colleagues, even my boss, is that I need to take care of myself: “make sure you manage your stress,” “be sure to get enough sleep,” “don’t work too hard,” etc. I do not recall hearing these mantras recited to me before my diagnosis.

Why is it that we need to be diagnosed with a life-threatening illness to have the permission to take care of ourselves? If we know that unhealthy diet, sedentary behavior, chronic stress, sleep deprivation, being overweight, and exposure to environmental toxins make our bodies more hospitable to cancer growth, shouldn’t we be encouraged to engage in behavior change before we are diagnosed with cancer? It seems that knowing is not enough.

It is time to focus on the doing of anticancer living and harness the power of the “mix of six.” This includes establishing a support team to foster your success and giving and receiving love and support; incorporating diaphragmatic breathing with relaxing imagery to start and end your day and ideally building up to a more robust mind-body practice; prioritizing sleep to get at least 7 hours a night; incorporating physical activity throughout your day and simply sitting less; filling at least half your plate with vegetables, eating more plant-based foods, limiting processed foods, and following a 90/10 rule - 90 percent of the food you eat is health supporting and no more than 10 percent health depleting; and using the precautionary principle to detoxify your environment and examine what you put in and on your body from the top of your head to the tip of your toes.

Anticancer living is built on the belief that self care is health care and that greater wellness is available to us all. No matter where we are on the spectrum of anticancer living, we should always be striving to take small steps to improve our health.

I know my life, and yours, depends on it.