“Why me?” is a question we all ask, often followed by, “But I eat healthily and exercise and never smoked so how come I have cancer and the guy at work who smokes three packs a day and is overweight doesn’t?” We all want to know what caused our cancers, but the short answer is scientists don’t know. How, why, where and even when our cancers develop is a combination of genetics, environment, timing, and overall health.1 Some say luck plays a role too.
As my doctor explained to me, we are all different and each of us has a unique cancer recipe, our own mix of ingredients that contribute to and help prevent cancer. When the contributory ingredients overwhelm the preventative ones, boom, cancer happens. But that doesn’t mean we are doomed. There are things we can do to help ourselves, even if we were born with an unfortunate genetic mix.
We Are All Mutants
Face it, we are all mutants. There are two different types of mutations: germline mutations — the ones we inherit from our parents — and somatic mutations — the ones that happen in our bodies. And we all have plenty of each.
Thanks to germline mutations, some of us are born with a genetic mix that pre-disposes us to getting cancer. For instance, mutations to the tumor suppressor gene, BRCA (BRCA1 and BRCA2 mutations) have been linked to an increased risk of breast and ovarian cancers. Having a germline mutation doesn’t mean for sure we will get cancer, but it introduces a weakness in the system that says we have a greater risk of cancer than those without the same mutation.2
And whatever cells we inherit from our parents, once they are ours, they are constantly replicating, some at an astonishing rate of 100 million per minute (like red blood cells). And each time a cell duplicates, it has the potential to mess up, letting a small coding error slip in. Most of the time, the immune system recognizes a bad cell and destroys it. But often, especially when the immune system is suppressed or overly stressed, bad cells can slip through the cracks. And sometimes these error-ridden cells — the somatic mutations — replicate and compound.3
But not all mutations cause cancer. In fact, scientists talk about driver mutations — the ones that cause cancer — and passenger mutations — the benign ones that just come along for the ride.4 But even that’s not the whole picture. Sometimes, the driver mutation only leads to cancer if a certain sequence of passenger mutation has already happened. In fact, many people have driver mutations and remain cancer-free in the absence of supporting mutations. Even where a mutation occurs within the gene can affect its ability to cause cancer.
Another variable that contributes to cancer is how and when our genes are activated. Not all our DNA is in use at any given time. Rather, some genes are turned on and off, a pattern called gene expression, that influences how our cells function. Gene expression helps determine whether or not a germline mutation will lead to cancer, and it can support or help prevent somatic mutations too.5
Environment plays a key role in gene expression. Toxins encourage mutations and everything that stresses the immune system can contribute to the toxic load on our systems. Too much sun; pollution in the air we breathe, the water we drink, and the foods we eat; plastics, formaldehydes, phthalates and petroleum-based chemicals in our homes, cleaning products, clothes, health and beauty products;even virusesincrease the burden our bodies need to handle. In fact, some products “generally recognized as safe” by the CDC can introduce a physical stress that our immune systems need to address, even if not specifically cancer-causing.
At the same time, diet and exercise can provide a positive influence on gene expression. Spend 30 minutes a day exercising, and genes that build muscle are turned on: your metabolism changes, as does your insulin response. Load up on vitamin-nutrient food and you turn on the genes that suppress inflammation and stimulate the immune system.6
Rusting on the Inside
And then there is something scientists refer to as oxidative stress. Think of it as rust, but inside our cells. Basically, just as oxygen causes iron to turn red and crumble over time, so too does it deteriorate our cells over time. The older the cell, the more oxidative stress it has undergone. The older the person, the more times her stressed cells have replicated, and the more likely a mutation enters the picture. So, yes, even age contributes to cancer.7
Diet can counteract some of the effects of oxidative stress. Blueberries and grapes and other sources of anti-oxidants help combat oxidative stress by preventing and repairing DNA damage, and by helping to keep damaged cells from replicating. The best way to get these benefits is by eating lots of fruits and vegetables, not by guzzling handfuls of mega vitamins. Too often, with supplements, the benefits are flushed down the toilet due to a mismatch in absorption and excretion rates.
Similarly, how well the immune system responds is a key ingredient in whether or not cancer develops. Having evolved to keep us healthy under a variety of circumstances, our immune systems generally recognize something that doesn’t belong, and will mount defenses to attack it. Some intruders are harder to deal with than others — we may be feverish for a week with the flu, and barely register a sniffle from a passing cold, but each is an immune response. Similarly, the immune system recognizes toxins and cell mutations and tries to eliminate them long before they lead to cancer.
Keeping your immune system in balance helps it identify and fight cancer, along with other invaders. That requires lots of phytonutrients, which also come from eating a colorful diet. Vitamin E, beta-carotene, Omega 3’s, the B vitamins. Our bodies need them all to maintain a strong defense, and as with anti-oxidants, they work better if derived from food sources not supplements. There’s something in the process of digesting the food-based nutrients that helps them work.8 Which leads us to the other key element in the immune system, the microbiome.
Turns out, even though we think we are humans, we are really just homes for billions of little critters living on the skin and in the gut. These microbes help digest nutrient-rich food and seem to empower our immune systems. Feed them, and you feed your built-in cancer-fighting machine. Recent studies have even shown that the microbiome can influence the effectiveness of cancer treatment, helping chemotherapy and immunotherapy be more effective.9
On the flip side, one of the major destroyers of immune health is chronic stress. In numerous studies, chronic stress has been shown to prevent normal metabolism, cause abnormal sleep-rest cycles, interfere with thinking and emotional stability, and generally drop the first line of defense of our immune response. That cold you caught after a couple of crazy weeks of extreme job stress, a new baby, and no sleep? Your immune system was suppressed, and the virus made it through your defenses. That’s when mutations slip in as well, some of which can lead to cancer. A little meditation, a 10-minute walk in the fresh air, a vacation from social media and constant smartphone activity, a good night’s sleep, and a deep belly laugh can all help reduce stress and restore internal balance.
Of course, it’s actually more complicated than that because our genes, experiences, and environment all contribute to how we perceive stress. That means what one person calls stress might be a walk in the park for the next, and what relieves stress for one might create stress for another. Some soldiers return from war and move on with their lives, able to reflect on their experiences but not relive them. Others experience PTSD. For some, a massage and full-body wrap is a luxurious pleasure, for others, a claustrophobic nightmare. Some people thrive in high stress situations — think stock traders and rock climbers — while others of us would be overwhelmed at the prospect. It’s only tough on the immune system when we experience it as stress, and it persists for a long time.
Everything in Moderation
As with most things in life, it’s all about balance. It’s the the collective influence of all these elements that keeps us healthy or allows cancer to grow. That’s why it’s so hard for doctors to say what caused a specific cancer. One person can appear to do everything wrong and not develop cancer, while another can appear to do everything right, and receive a devastating diagnosis.
We can’t control everything in the mix. We are stuck with the DNA we inherited, including any germline mutations that came with it. And we can’t stay 25 years old to prevent oxidative stress. But we can control a number of other things that reduce the mutational burden and strengthen the immune system. Minimize exposure to the sun. Eat a healthy diet. Exercise, but don’t wear yourself out day after day. Meditate, sing, knit, or do some other form of stress-reduction activity. Go outside and play. And then hope that your immune system kicks in when called upon to clear away toxins and random cell mutations before they become cancerous.
It also helps to be aware. Get your cancer screenings. Pay attention to what your body is telling you. And if cancer happens, do the best you can to support your immune health while following medical advice about treatment. There is no easy answer to why cancer happens to any individual, nor is there a universal formula to prevent it. But by understanding the catalysts of cancer and being proactive against them, we can improve our odds of staying healthy.
1PLoS Comput Biol. 2015 Jan; 11(1): e1004027. Published online 2015 Jan 8. doi: 10.1371/journal.pcbi.1004027.
2Science. 2015 May 22; 348(6237): 880–886. doi: 10.1126/science.aaa6806.
3Science. 2019 June 7; 364 (6444) 938-939). doi: 10.1126/science.aax5525.
4BMC Bioinformatics. 2014; 15(1): 308. Published online 2014 Sep 19. doi: 10.1186/1471-2105-15-308.
5PLoS Genet. 2016 Jan; 12(1): e1005755. Published online 2016 Jan 6. doi: 10.1371/journal.pgen.1005755.
6Arch. Pharm. Res. (2017) 40:1219–1237 DOI 10.1007/s12272-017-0973-3.
7International Journal of Cancer / Volume 137, Issue 11. First published: 15 June 2015 https://doi.org/10.1002/ijc.29639.
8Phytochemicals and Cancer, MD Anderson Cancer Center, January 2017.
9The ASCO Post, April 25, 2019, The Microbiome: The Next Target in Cancer Therapy.