Download Preventing Cancer

Preventing Cancer
About 41% of the US population is expected to be diagnosed with cancer
during their lifetime. In 2009, an estimated 562,340 people died from
cancer-related causes. Obesity, lack of physical activity, and poor diet may
account for about one-third of these deaths.
What is cancer?
Cancer is a group of diseases caused by the growth and spread of abnormal
cells. Uncontrolled spread of cancer cells can lead to death. Agents, such as
tobacco, radiation, or certain chemicals, may work together with genetic,
hormonal, nutritional, and other factors to initiate and promote the growth
of these abnormal cells. Cancers of the lung, breast, prostrate, pancreas,
colon and rectum are the most common types.
How are poor diet and lifestyle related to cancer?
Several lifestyle factors are associated with increased risk of different types
of cancer. Cigarette smoking is by far the most important factor related to
lung cancer. Dietary factors are thought to be related to cancer of the breast
(after menopause), endometrius, colon, kidney, mouth, pharynx, larynx, and
esophagus. Obesity, lack of physical activity, a diet that is high in red meat
or processed meals, heavy smoking, and low intake of fruit and vegetables,
have been associated with greater risk of cancer of the colon and rectum.
Consumption of milk and calcium reduces risk of these colorectal cancers.
Although age, ethnicity, and family history are the major risk factors
associated with prostrate cancer, studies also suggest a link between
prostrate cancer and high consumption of animal fat and low intakes of fruit
and vegetables.
Why does the public often hear conflicting messages about diet and
cancer?
Scientists rely on different sources of evidence to establish a relationship
between diet and health. Some epidemiological studies may involve
observing the dietary patterns and health outcomes of a large number of
individuals over time. In such studies, identifying a nutrient or food that is
protective against cancer can be difficult because there may be many other
factors, not measured in the study, that influence health outcomes. The
strongest evidence comes from clinical interventions, where research
subjects are randomly assigned to different treatments or control, nontreatment groups. Since cancers may develop over the course of many
years, some of these studies may not be long enough to find an effect. In
other cases, the amount of food or nutrient provided in the study may be too
low to have an effect on health.
References
American Cancer Society. Cancer Facts and Figures. 2009. Available at:
http://www.cancer.org/Research/CancerFactsFigures/CurrentCancerFactsFig
ures/500809web-pdf. Accessed March 4, 2011.
US Department of Health and Human Services, US Department of
Agriculture. 2011. Dietary Guidelines for Americans 2010. Available at:
www. dietaryguidelines.gov Accessed January 31, 2011.
Produced by Dr. Lucia Kaiser, Department of Nutrition, University of California at Davis, March 2011.
For educational purposes only: not for resale. The University of California does not discriminate in any of
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