Load up on plant food. Use your gym membership. Apply
sunscreen religiously. Steer clear of cigarettes. Taking on healthy
behaviors like these is supposed to lower your lifetime cancer risk.
Now, along comes a bombshell study that seems to suggest many of these
odds-lowering efforts are less impactful than you may have previously
thought: The study, from Johns Hopkins University, determined that
two-thirds of all adult cancer incidences can be attributed to random
gene mutations that drive tumor growth. In other words, most incidences
of cancer are caused by plain-old bad luck, according to study authors.
The study came about because researchers wanted to
understand why some body tissues, such as those in the small intestine
and pancreas, have higher cancer risk rates than others. So they tracked
the number of stem cell divisions that happen across 31 tissue types,
comparing these figures with the lifetime risks of cancer in these same
tissues among American adults. The conclusion: The higher the number of
cell divisions the tissue endures, the higher the cancer risk rate was.
“Our study shows, in general, that a change in the number of stem cell
divisions in a tissue type is highly correlated with a change in the
incidence of cancer in that same tissue,” said study investigator Bert
Vogelstein, M.D., the Clayton Professor of Oncology at the Johns Hopkins
University School of Medicine, in a news release. The more cell
divisions that happen, the greater the chance that a random mutation
occurs—and malignancy develops.
So should you throw in the towel when it comes to healthy
living since the study results imply that cancer is mostly out of your
hands? That would be a resounding no. Though the researchers identified
22 cancer types with risk rates largely driven by random mutations, nine
others—such as one type of skin cancer as well as head and neck,
colorectal, and lung cancer—were tied to environmental factors you can
at least partially control, in this case exposure to UV rays and
smoking. These nine were also influenced by hereditary factors, which
means that regular screenings can help you ID a tumor before it becomes
life-threatening. Also, if you’re worried about breast cancer, this
study offers no answers, as researchers didn’t look at breast tissue at
all.
The other thing is, “random” mutations aren’t necessarily
random at all, says David Katz, M.D., M.P.H, director of the Yale
University Prevention Research Center. Instead, they may arise as a
result of lifestyle factors. “Mutation rates are higher in those exposed
to toxins and lower in those exposed to health-promoting conditions,”
says Katz. “Studies have already shown that cancer-promoter genes are
turned off and cancer-suppressor genes turned on by healthy living; this
doesn't change that."
Bottom line: Cancer is a collection of diseases caused in varying
degrees by genetics, environmental factors, and the random gene
mutations cited in the Johns Hopkins study. Since some cancers offer
more leeway than others for you to reduce your odds, it’s smart to adopt
healthy behaviors that could do just that: Stick to a diet low in
animal fat and high in fruits and veggies, get regular physical
activity, and minimize your exposure to UV rays and cigarettes,
suggests the American Cancer Society.
Thanks for Reading........
No comments:
Post a Comment