Alison and I travel regularly to give talks about adopting an anticancer lifestyle to audiences that include both cancer survivors and those hoping they and their families will never face this daunting challenge. I present the scientific evidence linking lifestyle and cancer, and Alison shares strategies on how to make lifestyle changes permanent and sustaining, as she does in this book. After one of our recent talks, a young woman with breast cancer came up to the front of the room, shook our hands, and told us her story. The previous year, she had gone through a difficult divorce. While fighting for custody of her two children, she was laid off from her job at a local shipping company. Six months later, she was diagnosed with stage II breast cancer. “I had never been without work,” she said. “That and the divorce, the stress from those two things, that’s what caused my cancer. I’m sure of it.”
We hear this level of certainty about what caused someone’s cancer from at least one person in the audience at every presentation we give, no matter where we are, how many people are in attendance, and regardless of the specific focus of the talk. The first thing we should make clear is that if you get cancer, no matter what kind or what stage, the exact cause is almost never clear. While the recommendations in this book have been shown to reduce cancer risk, especially when practiced in combination, no one is immune to cancer, just as no one is destined for it.
If I were to ask a random sampling of people what they believe causes cancer, I’d get a broad range of answers, many of them correct. Some might say cigarettes cause lung cancer, which is absolutely true. Others might say radiation or environmental pollution or infection with a cancer-causing virus—all of which are also true. And lately, with our ever-expanding understanding of genes and how they work—specifically as they relate to cancer—more and more people would respond “our genes!” with an almost gleeful sense of certainty. This answer, of course, is also true, but it’s also largely false.
Let me explain.
Malfunctioning genes are clearly the cellular mechanism that allows a cell to become what we call “cancerous.”1 But this complex process is most often triggered by something external to that cell—often something external to the human body—and this is the root of the confusion about whether the gene malfunction that prompts uncontrolled cell growth, leading to the formation of cancer, is mainly hereditary or externally triggered.2–4
It’s fair to say that, given the amount of research funding pouring into genetic research, the gene has been a recent darling of the cancer world. Since the sequencing of the human genome in 2003, our understanding of the intracellular behavior of genes and how they contribute to the development of cancer has been nothing short of transformative. But our understanding of gene behavior, and especially of what influences gene behavior, is still in the very early stages. Nevertheless, there is a widespread misconception that inherited gene mutations are primarily responsible for most cancers.5 The public believes that we are either born lucky, free and clear of inherited cancer risks, or unlucky, hardwired to get certain cancers based on the luck of the DNA draw. Nothing could be further from the truth. And for all of us—including those of us with inherited genetic mutations that increase the risk of cancer—this is actually good news.
Only 5 to 10 percent of all cancers are caused by inherited genetic mutations.6,7 Most experts feel that the number hovers tightly around the 5 percent range. For people born with genes that indicate a high risk of developing cancer (such as the BRCA-1 and BRCA-2 genes, which are associated with increased risk of certain breast and ovarian cancers), getting cancer is never a certain fate.8 For example, women with the BRCA-1 mutation have a 55 to 65 percent chance of developing breast cancer by age seventy (the risk for women with the BRCA-2 mutation is 45 percent), relative to only 12 percent for the general population.8 Similarly, the rate of ovarian cancer for BRCA-1 carriers is 39 percent (11 to 17 percent for women with BRCA-2) versus 1.3 percent for the general population.8
This focus on genetics and genetic mutations also veils an important truth: Up to 95 percent of all cancers are not caused by inherited genetic defects.6,7 Some of course are due to chance. But most cancers are caused by something within our power to control—the way we live and the choices we make every day.2,6,7,9
In 2010, Gabe Canales was on top of the world. A young entrepreneur living and working in Houston, Texas, he ran his own marketing and public relations firm, where his clients included high-profile restaurants, tech, real estate, and higher education companies. He was successful, very social, and in good health. During a routine annual checkup, he was given a spate of tests, including a PSA (prostate-specific antigen) screening. He got a call from his doctor saying that his PSA levels were a bit elevated. So he went back for a second test, and this one indicated an even higher PSA level. His urologist recommended Gabe have a biopsy, but when Gabe realized it was an invasive procedure (a probe is threaded up through the rectum and a microscopic knife slices samples from the prostate gland), he declined. The doctor followed up and pressed him, “Look, it’s just going to be a pinch. Just a pinch and you can go back to work.”
The procedure was much more than a pinch, as Gabe explains: “The topical numbing agent and the local anesthetic did not work, so I felt it every time this probe was threaded up through my rectum and a snippet of my prostate gland was taken. I felt like my body was imploding. It was the most excruciatingly painful experience I had had in my life to that point. I remember thinking, ‘When will this end?’ It was god-awful.”
A week and a half later, Gabe was walking out of his house, gym clothes on, car keys in hand, when he got a call from the hospital. His urologist told him he had some bad news and some good news. “The bad news is you have prostate cancer. The good news is you’ll be fine.” All Gabe heard was, “You have cancer.”
Gabe’s urologist told him he needed surgery. “We need to take it out.” The side effects of prostate cancer surgery included a period of impotency and incontinence. “Here I was, a single, thirty-five-year-old guy with my whole life ahead of me. I needed a second opinion.”
The next doctor told Gabe the exact opposite. He suggested a “wait-and-see” approach. Gabe imagined that he would think of little else aside from whether his cancer was growing and spreading inside his body. Did he really have only two choices—to undergo major life-altering surgery or to do nothing?
Gabe went to Memorial Sloan Kettering Cancer Center (MSKCC) in New York City to get another opinion. The MSKCC doctor, after a series of tests, also recommended “active surveillance.” He explained that if they monitored the tumor closely, Gabe might not have to do anything for five, ten, or even fifteen years.
Less panicked, but still not totally satisfied, Gabe went to see one more doctor, Dr. Aaron Katz, chair of urology at NYU Winthrop Hospital and professor of urology at Stony Brook University School of Medicine (who at that time was an attending urologist at Columbia University). “That’s when my life changed.” Dr. Katz addressed an issue that had not been brought up before: nutrition. He recommended that Gabe radically change his diet—from meat and potatoes to a plant-centered, vegetable-heavy meal plan. “It’s not that he recommended some crazy, unreasonable diet—it was just the opposite. He wanted me simply to make a conscious effort to eat less steak and potatoes, drink less beer and liquor, and eat more fresh vegetables and fruits—of which, at the time, I ate exactly none. I flew back to Houston and decided to take his advice.”
Gabe began to educate himself, and he also started to lose weight and build lean body mass. When he went in for his first regularly scheduled surveillance visit, his blood work showed that his PSA level had gone down. “I had that aha moment when I realized that altering my diet as the doctor I had met in New York recommended was working. I knew, without a doubt, that I had some input over the outcome of this cancer. I needed to know more! So I began to really explore how lifestyle and cancer might be interrelated. One of my daily routines was drinking two to three large glasses of blended spinach, kale, cilantro, and jalapeno—just green vegetables.”
Today, Gabe is a walking, breathing example of anticancer living and has become a close friend and colleague (I am on the board of directors of his nonprofit, Blue Cure). He will never know what “caused” his cancer, but he’s found his purpose and he’s now in the best health he’s ever been in. Through his nonprofit, he’s bringing the anticancer living message to young men and boys across the country, believing that prevention of prostate cancer—which is affecting younger and younger men—is a better alternative to a cure.
We know that inherited genetic anomalies, though a great threat to a very small part of the population, aren’t the main culprit when it comes to cancer.
When we get out of the laboratory and take a look around, we’re actually confronted with two worlds. Off in the distance, moving farther and farther away from us, is the untainted natural world. Before the start of the Industrial Revolution, nature was able to provide us with everything we needed to live well: clean air, clean fresh water, abundant food sources, and beautiful terrain to move around in. Of course, there were diseases, famines, natural disasters, and other threats to human life, but the basics for healthy survival were there, too.
While our modern minds worked hard to make life easier and, where health care was concerned, prioritize longevity, we unintentionally shrouded the earth in a haze of pollutants that not only taint and harm the environment but also interfere with the ability of all living things to fully flourish—including us. It’s undeniable that we are living longer, but we’re also now faced with diseases that come with the longevity we’ve bought at the expense of disease prevention. What a terrible irony! The only silver lining in this is knowing that, since we’ve created the causes of so much illness, we can also eliminate them.
Alison and I grew up hearing the advertising slogan, Better Living through Chemistry. This was the bright, happy jingle of the DuPont Chemical Company from 1935 until 1982—when “through chemistry” was finally dropped. If you grew up during that period, you know that “chemistry” was supposed to encompass all the benefits and convenience that chemicals and additives brought to modern life. By the 1980s, however, when the slogan had come to be regarded as a cynical catchphrase, most of the world was finally catching on that perhaps living in a world chock-full of chemicals wasn’t better after all.
Nowhere is the irony of this more obvious than in the realm of cancer care. Over the past thirty or so years, we’ve established a direct link between man-made chemical agents and the onset of cancer.10,11 Yet we still mainly treat these chemically triggered illnesses with other chemicals in the form of chemotherapy. We get sick because of chemicals and we try to get better with chemicals. In the meantime, the costs to our bodies, our health, and our overall quality of life continue to mount.
What if there is a better way?
We now have some of the scientific data we need to make choices that sidestep many of the industrial and environmental chemical toxins laced into the foods we eat, the clothes we wear, and the products we use in our daily lives.
Here are just a few facts about factors that cause more than 50 percent of cancers:
Diet, sedentary behavior, and obesity are responsible for 30–35 percent of all cancers in the United States.12 It is estimated that almost 1 in 6 cancer deaths in men and 1 in 5 cancer deaths in women are associated with being overweight.12
Tobacco is responsible for about 30 percent of all cancer deaths worldwide (though death rates from tobacco-related cancers in the United States have dropped significantly in recent years; tobacco-related deaths continue to rise in the developing world).12,13
Viral infections, such as those caused by Epstein-Barr, HPV, and hepatitis, account for more than 15 percent of cancers worldwide. (Vaccines are now available to protect against infection from the types of HPV that cause cancer. Also, the Epstein-Barr virus causes cancer only in rare cases.)12
Up to 10 percent of cancers are caused by radiation. This includes UV rays from the sun, which cause skin cancers, one of the fastest-growing cancers among young adults.12,13
Alcohol is listed by the National Toxicology Program as a known human carcinogen.14 The more someone drinks, the higher their risk of developing certain types of cancers including head and neck, esophageal, liver, breast, and colorectal.15,16 In 2009, an estimated 3.5 percent of cancer deaths in the United States were alcohol related.16
Environmental toxins that are known to cause cancers, such as asbestos, coal dust, and formaldehyde, to name just a few of thousands, are widespread.10,11,14 Scientists have no way of quantifying the link between specific environmental toxins and cancer onset, except in the most obvious cases (for example, coal miners have a higher-than-average incidence of respiratory cancers as a result of their exposure to the carcinogens in coal dust and asbestos, which cause mesothelioma).
Tobacco use, of course, is the great example of a lifestyle choice or, if you prefer, an addictive habit, that is directly linked to cancer. Whether it’s social, a secret vice, an anxiety release, or a style statement, for the past fifty years or so, we’ve known that tobacco, which contains more than 50 carcinogens, is a primary cause of at least fourteen types of cancer, including lung and head and neck cancers. Tobacco alone accounts for a third of all cancer deaths annually, and more than 80 percent of all lung-cancer deaths. What exactly happens when the substances found in tobacco interact with healthy cells is quite complex, but what is known is that when we don’t smoke, or when we quit smoking, our risks for developing tobacco-related cancers decline significantly. There is clear evidence that quitting smoking has immediate benefits to our health and these benefits accumulate over time.17
The acute benefits of quitting smoking are realized quickly. The harms are such that surgeons will often not operate on active smokers due to the heightened complications and postoperative infections. However, most surgical oncologists will be able to operate on someone who has stopped smoking in as little time as a week before surgery. After ten years of being smoke-free, your risk for many tobacco-related cancers is cut in half.16 Smoking cessation once someone has been diagnosed with a tobacco-related cancer improves the odds of survival and decreases the risk of developing a secondary cancer. For example, a meta-analysis of ten studies of people with lung cancer found that those who quit smoking at the time of diagnosis had a five-year survival rate of 63 percent and 70 percent for small-cell and non–small-cell lung cancer, respectively, versus 29 percent and 33 percent, respectively, among those who continued to smoke.18 The same is true for a number of other tobacco-related cancers.16
What’s truly fascinating is what happens when you combine smoking with another lifestyle choice, such as drinking alcohol. Those of us who’ve smoked in the past know how great a cigarette can taste when paired with a beer or a cocktail. What most of us don’t know is that the carcinogenic effects of both tobacco and alcohol (which is independently linked to liver, breast, and digestive-tract-related cancers, among many others) are enhanced when they are combined.15,19–21
In other words, there is a negative synergistic effect when more than one cancer-related lifestyle factor is at play, and scientists cannot measure which substance is responsible for increasing the cancer-related risks when they are combined. What scientists do know, in the case of tobacco combined with alcohol, is that there can be a multiplicative risk of developing cancer.19,20,22 If you smoke, drink, and are sedentary, your cancer risk increases. If you smoke, drink, are sedentary, and eat an unhealthy diet made up of mostly processed foods, your cancer risks rise even further.
The good news is that making changes in just one area of your life can significantly reduce your risk for developing certain cancers.23–28 Making changes in more than one area will have a positive synergistic impact, reducing the odds of developing cancer or improving outcomes for those with cancer even more.23–28 As Steve Cole, PhD, professor of medicine at the University of California, Los Angeles, wrote, “The old thinking was that our bodies were stable biological entities, fundamentally separate from the external world. But at the molecular level, our bodies turn out to be much more fluid and permeable to external influence than we realize.”29
While we may never know what causes someone’s specific cancer, we already have the answer for what reduces our risk and what changes we can actively make to slow cancer’s growth and prevent it from spreading. Our knowledge of cancer’s unique process can help us move forward in a more logical way, removing the veil of fear that prevents us from looking cancer in the eye. We know enough about this disease to confront it directly and take steps to confound its progress and take back control of our health.