Go backCan Your Lifestyle Impact Cancer?
Wouldn’t it be nice to know what -- and what not to --do to avoid cancer? When I was first diagnosed with breast cancer, my wise doctor told me that many of his patients, upon hearing the devastating news, tried to pinpoint what they “did” to give themselves cancer.
“If they could blame themselves for what they did ‘wrong,’ it gave them a sense of control again over their body—the body that failed them by developing cancer for no apparent reason,” he said.
However, I completely threw out his advice of avoiding self-recrimination after I finished my year of treatment. After you survive the ordeal of chemo, surgery and radiation, you never want to hear, “You have cancer” again.
So, I became obsessed with avoiding anything that could possibly ignite cancer in my body and maniacal about doing all “the right things” – whatever they were—to prevent the disease. The problem, though, was figuring out exactly what were THE right and wrong lifestyle choices regarding cancer.
Should I eliminate red meat from my diet? What about preservatives? What about exercise? But, wait! I know someone who has smoked like a fiend and eaten junk food for years and has never developed cancer. Meanwhile, I, the health nut, who juiced every morning and exercised like it was my career, got cancer. So what can I believe? Do our lifestyle choices have any bearing on getting cancer or not?
After talking with Gregg Orloff, Ph.D., who has developed an award-winning web site on the biology of cancer (www.cancerquest.org), the best I can understand is that lifestyle choices do and don’t contribute to cancer. Just what we all want to hear.
“Of all the environmental and behavioral factors that have been investigated for cancer, only a few have shown a clear link,” Orloff says. “It’s difficult to make hard and fast conclusions about certain activities and their impact on cancer because studies to-date haven’t involved a large enough population or haven’t been conducted for a long enough time period to offer anything definite. The data simply doesn’t exist at this point.”
Still, research has uncovered enough implications between particular behaviors and increased risk that it’s worth paying attention to how lifestyle choices impact our health, he says. But in order to understand how behavior and cancer are related, we first need to know what causes cancer to form.
"Cancer is ultimately a result of DNA damage," explains Orloff, who is a senior lecturer in biology at Emory University in Atlanta.
“We know that cancer is derived from a single defective cell that has multiplied,” he says. “It occurs when a cell strikes out on its own, resulting in unregulated cell growth. These abnormal cells pile up on each other and form masses, which are commonly known as tumors.”
But why does a normal cell strike out in the first place? What causes it to become cancerous?
It happens when a particular set of genes in a cell are altered by mutagens. And, this is where lifestyle behaviors may play a role in cancer. Mutagens enter the human body by means of inhaling, ingesting and absorbing. They derive from:
- Chemicals in the diet—For example, charred meat from grilling (the burning process) can cause the formation of chemicals that are thought to be mutagenic.
- Infectious agents —A problem can occur when a virus actively alters the cells. For example, cervical cancer may result after infection with the Human Papilloma Virus..iral infection.
- Chronic infections—Cancer can result in RESPONSE to an infection. For example, hepatitis has been associated with liver cancer. When cells are killed by infection, they need to be replaced constantly, so there are high amounts of cell division occurring in these tissues. In addition, the body’s immune response to fight infection is producing chemicals that can cause mutations.
- Chemicals in the environment —These can be absorbed or inhaled, such as smog (pollution) and industrial waste.
In other words, every time you expose your body to a cancer risk—eating burned meat, inhaling cigarette smoke or absorbing coal tar—mutagens enter your body. And chemicals that are mutagenic can cause DNA damage.
The Luck Factor
If everyone takes in mutagens, then why does one person develop cancer over someone else?
"In order for a single, normal cell to turn into a cancer cell, it must acquire five to six different changes from mutagens. So, it’s a cumulative effect,” says Orloff. “Two people can be exposed to the same mutagen, but in one person, the cell dies or remains the same, while the other person acquires a mutation in an important gene and develops cancer. That’s why you see some people smoke their entire lives and not get cancer, and others who ‘do all the right things’ who do get cancer. Luck plays a big role as to who gets cancer and who doesn’t.”
There are genetic components to cancer, as well.
“A person can inherit defective genes—such as BRCA1—which by itself doesn't necessarily cause cancer,” Orloff adds. “But a defective gene can increase your chances that some important key genes will be affected by a mutation, giving you a higher risk for cancer.”
Another genetic factor that can affect whether one person gets cancer versus another is possessing better DNA repair genes, which respond to changes in DNA differently.
In addition, the way your body processes toxins can affect your chances of getting cancer. For example, the liver has enzymes to process and eliminate toxins—making them soluble so they can be excreted. But this detoxification process can convert a chemical into a mutagen. Consequently, two people may be exposed to the same risks, but their bodies may process toxins differently.
Whatever your body’s genetic makeup, DNA can be damaged by certain behaviors. The following factors are known to have an associated risk of cancer because of their mutagenic properties
- Smoking—Full of mutagens, smoking as well as second-hand smoke is connected to almost all cancers.
- Sun damage —UV rays are mutagenic and have been proven to cause skin cancer.
- Diet & Obesity—Obesity carries an increased risk of breast and colon cancers. Certain diets can alter the level of growth factors and nutrients (proteins, lipids, sugars) in the blood, which in turn, can stimulate normal cells to become cancerous, or cause existing cancer cells to grow.
- Alcohol—Particularly a risk factor for breast, colon and esophageal cancers, alcohol is toxic and must be detoxified, causing stress on the body. The detoxification process can cause DNA damage.
- Medications—Certain drugs can potentially cause a problem. For example, female children of women who took DES (now outlawed) while pregnant have higher incidences of cervical and uterine cancer.
On the other hand, there appear to be certain behaviors that might help reduce your risk of cancer.
Exercise – In some studies, exercise has been shown to have positive beneficial effects on breast and colon cancer. The benefits of exercise may be due to a wide variety of effects, ranging from enhanced immune system function to increased GI motility.
Diet – Overall, a well-balanced diet with fruits, vegetables and nuts is beneficial. Specifically, foods that contain antioxidants, such as leafy green and cruciferous vegetables, have cancer fighting possibilities.
Why is this? Because our bodies produce oxygen radicals, which are highly reactive molecules in cells that act as mutagens and can cause DNA damage. Antioxidants act as interceptor missiles, neutralizing oxygen radicals before they affect DNA.
In addition, studies have indicated that vitamin E, selenium and calcium might potentially prevent or limit cancer growth.
“Again, none of these things, alone, offers a huge reduction in cancer risk,” warns Orloff. “But we know enough from studies to advise people to take care of their body.”
The Bottom Line
"There's no holy grail in that if you do this set of behaviors, you won't get cancer," says Orloff. "All you can do is limit your risks.
"It's like avoiding a car accident. You can limit your risks by wearing a seat belt, not going out late at night, and not driving while talking on a cell phone. But all these things still can't guarantee that you won't get killed in car accident.
“The same goes for cancer. Individuals have to decide what risks they want to live with.”