Cancer is a scary diagnosis. Fortunately, treatments are extending the lifespan and even curing some cancers. Yet, the best “treatment,” is still prevention. Although we don’t know exactly what causes cancer, the best theory is that it comes from an accumulation of mutations in DNA, the genetic material that controls how cells behave. Mutations are changes in the sequence of DNA, the roadmap that tells cells how to divide and what their boundaries are.
Some mutations are silent, they don’t necessarily affect cell behavior or the health of the cell. But, over a lifetime, cells accumulate lots of these mutations and some can cause cells to behave abnormally, lose their ability to regulate growth and replicate out of control. Cancerous cells no longer obey signals that tell them to stop dividing. As a result, they grow in an uncontrolled manner, eventually invading normal tissues and organs. Some even gain the ability to enter the lymphatic system, and eventually the blood, and travel to distant organs. If not impeded, they can slowly destroy the host.
If the mutation theory of cancer is correct, the way to lower the risk of cancer is to prevent the accumulation of mutations that allow a cell to grow uncontrollably. Some of these mutations happen due to “bad luck.” You can also be born with mutations that boost susceptibility to cancer. With inherited mutations that increase the risk already present, a cell may only need another mutation or two to transform a normal cell into a malignant one. Unfortunately, we can’t control factors like luck or genetics. However, cells also accumulate mutations from environmental exposures, the stuff you’re exposed to from the environment and through diet and lifestyle. There, we do have some control of.
By now, you’re probably wondering what percentage of cancers are preventable? According to a recent study, more than 40% of all cancers are preventable through lifestyle. That’s a healthy chunk! This means we have some control over our risk of developing cancer and we can lower the risk by making small, sustainable lifestyle changes. Other studies have come to similar conclusions and the World Health Organization backs up these findings, saying that 30 to 50% of cancers are preventable.
Reduce Your Exposure to Known Carcinogens
Remember how we talked about mutations? One of the biggest triggers for DNA mutations is smoking. Cigarettes contain thousands of chemicals. Some are known to damage DNA while others we don’t know enough about to say if they do or don’t. What is clear is that, based on data from the World Health Organization, smoking is the number one biggest avoidable risk factor for dying cancer. Smoking doesn’t just cause lung cancer, it contributes to a host of other cancers, including malignancies of the mouth, throat, larynx, esophagus, kidney, bladder, pancreas, stomach, and cervix. So, the take-home message is don’t smoke or quit if you already do.
You may have heard that drinking a little alcohol daily may lower the risk of cardiovascular disease by raising HDL-cholesterol. However, this slightly lower risk may be offset by an increased risk of developing certain cancers. In women, more than one alcoholic drink daily is linked with an elevated risk of breast cancer. Plus, alcohol consumption is associated with a higher risk of cancers of the head and neck, esophagus, liver, and colon/rectum.
You might assume you have to drink a lot of alcohol to increase your risk of these cancers, but more recent research suggests that drinking as little as one glass of alcohol daily boosts the likelihood. If you won’t eliminate alcohol entirely, follow the American Cancer Society’s guidelines and limit alcohol to one drink daily if you’re a woman and no more than two daily if you’re a man.
Can You Eat Your Way to a Lower Cancer Risk?
Another major risk factor for cancer is obesity. In fact, obesity is linked to 13 types of cancer. You might wonder how being significantly overweight boosts the odds. For one, fat cells excrete cytokines, chemicals that cause inflammation. Inflammation damages cells and tissues, making them prone to malignant change. People who are obese often have higher levels of estrogen circulating in their blood. Higher estrogen is linked to cancers of the breast and uterus after menopause. So, controlling your body weight through diet and exercise can help you avoid certain cancers.
What about specific dietary components? Some studies link a diet richer in fruits and vegetables with a lower risk of cancer, particularly cancers of the colon and breast. When you eat more vegetables and fruits, you also consume less meat. Processed meat and, in some but not all studies, red meat is linked with a higher risk of some cancers, including cancers of the colon and pancreas, and the risk is better defined for processed meat. It’s a difficult association to prove since people who eat lots of processed meat and red meat tend to have less healthy lifestyle habits which act as confounders. But, we could all stand to eat more fruits and vegetables!
Don’t Forget to Move Your Body
Exercise not only helps with weight control, it may lower the risk of cancer in other ways. Women who take part in endurance exercise tend to have lower estrogen levels. This may reduce their risk of uterine and breast cancer. A number of studies support this. Plus, moderate exercise has an anti-inflammatory effect. The evidence is strongest for colon cancer as it has been the best studied. A meta-analysis of 52 studies found that those who were the most physically active had a 24% lower risk of developing colon cancer relative to those who were the most sedentary.
We’re constantly exposed to chemicals in the environment and in our homes that can damage DNA. Research the cleaning products you use and opt for natural alternatives, like vinegar and baking soda, when possible. Get a full report of what’s in your drinking water. If you don’t like what it says, install a water filter. These small exposures may have a cumulative effect. Also, some infections are linked to specific types of cancer. For example, hepatitis B and C, caused by a virus increase the risk of liver cancer. Consider getting vaccinated against viruses that are associated with cancer, if one is available.
WebMD. “Study: More Than 4 in 10 Cancers Preventable”
World Health Organization. “Cancer Prevention”
American Cancer Society. “Alcohol Use and Cancer”
Oncotarget. 2017 Oct 10; 8(47): 83306–83314.
PLOS One. “Health risk factors associated with meat, fruit and vegetable consumption in cohort studies: A comprehensive meta-analysis”
National Cancer Institute. “Physical Activity and Cancer”