that at least
7 cancers have been
linked to alcohol intake?
Diet and Cancer: You Are What You Eat and Drink
Dietary factors are important, but they do not appear to be
uniformly relevant to all forms of cancer. The strongest scientific
evidence is for alcohol intake, which has been linked to an
increased risk for developing mouth, throat, larynx, esophagus,
liver, colorectal and breast cancers ( 8). For each of these cancers,
the risk increases with the amount of alcohol consumed, as
highlighted by a recent study showing that even a few alcoholic
drinks per week increase a woman’s breast cancer risk ( 38).
Developing and implementing more effective public health policies,
media campaigns and education initiatives will be key to
decreasing alcohol consumption, with the latter being particularly
important given that almost 39% of high school students report
current alcohol use ( 29).
For dietary factors other than alcohol, only limited research
conducted thus far supports a direct link to cancer risk ( 8). Red
meat and processed meat are both clearly associated with an
increased risk for colorectal cancer, but for other cancers, their
influence on risk is less certain scientifically. Moreover, no
unequivocal evidence of preventive effects exists for any dietary
factor, although some studies indicate the risk for some cancers is
reduced through the consumption of fruits, vegetables and fiber.
The complexities of the relationship between food and nutrient
intake and cancer risk are a key reason for the lack of a strong
evidence base in this area. Designing scientific studies to
determine the contribution of a single dietary component is very
challenging. Despite this, it is imperative that we continue to build
upon our knowledge of the causes of cancer and increase the
number of cancers that we can prevent.
Causes of Cancer That Are Hard to Avoid
We have discussed cancer risk factors that are possible to avoid,
but there are other risk factors that are more difficult to elude.
Ionizing Radiation: Energizing Cancer
Extensive epidemiological and biological evidence links exposure to
ionizing radiation with the development of cancer, in particular,
leukemias and breast, lung, brain and thyroid cancers ( 39). Ionizing
radiation is emitted from both natural and man-made sources (see
Fig. 13, p. 34). In the U.S., 82% of annual exposure to ionizing
radiation is composed of natural background radiation; the
remaining 16% comes from man-made sources ( 39).
The main natural source of ionizing radiation is radon gas, which is
released from the normal decay of certain components of rocks
and soil. It usually exists at very low levels outdoors, but can
accumulate to dangerous levels in areas without adequate
ventilation, such as underground mines and home basements.
Radon gas is the second leading cause of lung cancer after
smoking and is responsible for between 15,000 and 22,000 deaths
from lung cancer per year ( 40). This information led to policies for
reducing exposure through home and business inspections and
methods to contain or eliminate the source when possible.
Increased awareness, along with further deployment of mitigation
strategies, should further reduce the incidence of lung cancer
caused by these exposures.
The predominant man-made source of ionizing radiation is medical
equipment, treatments and diagnostic agents. Experts are
concerned about the recent dramatic rise in the frequency of X-ray
use for diagnostic purposes, such as CT scans ( 39). Thus,
approaches are underway to limit radiation exposure from
diagnostic CT scans with the use of new low-dose scanners. Also,
educational programs have been launched to reduce the number of
these procedures and to reduce radiation doses to what is
“[This] is the time to reaffirm our further commitment to finding treatments, cures and better tools
for prevention, building on the momentum of recent years. As the members of the American
Association for Cancer Research and their partners continue their quest for cancer prevention and
cures, Congress must stand behind them and invest in our research infrastructure.”
Representative Lois Capps (D-CA-23rd)
Co-Chair of the House Cancer Caucus