38.17:
Cancer Prevention
Cancer is a genetic disease caused by alterations in the critical genes that control cell growth and proliferation. However, there are many factors that can lead to such genetic changes in an individual.
For example, parents with cancer-causing mutations may pass these on to their children, predisposing them to cancer.
Such cases of hereditary cancer can be prevented with the help of genetic testing. It can help an individual assess the risk of developing cancer and decide a future course of action for screening and prevention.
Inherited genetic mutations such as these play a significant role in about 5 to 10 percent of all cancers.
However, there are also various lifestyle and environmental factors that can increase the likelihood of a person developing cancer.
For example, prolonged exposure to the chemicals present in tobacco smoke or atmospheric pollutants can increase the risk of cancer.
Upon inhalation, the polycyclic aromatic hydrocarbons or PAHs in the smoke react with metabolic enzymes present in the pulmonary cells, giving rise to reactive metabolites that can directly interact with DNA and induce genetic mutations. Such DNA damage can ultimately lead to tumorigenesis.
Besides tobacco smoke, other lifestyle-associated factors such as higher consumption of processed meat, obesity, lack of exercise, or excessive alcohol consumption are common causes of cancer. The incidence of such cases can simply be reduced by educating the general public on the benefits of adopting a healthier lifestyle starting at an early age.
In addition to lifestyle-associated risks, individuals may be exposed to cancer-causing agents present in their immediate environment. For example, prolonged exposure to UV radiation can lead to skin cancer, which can be prevented by reducing exposure to the sun and other sources of UV radiation, such as tanning booths.
Similarly, the best way to prevent cancer caused by other industrial or environmental chemicals, such as asbestos, is to take the appropriate steps like the use of PPE kits to prevent or reduce exposure.
Some viruses, such as the Hepatitis B virus and the Epstein-Barr virus, can play an important role in causing cancer in humans. Such viruses can either weaken the host immune system, directly damage the host cells’ DNA, or introduce oncogenes into the host cells.
Such virus-associated cancers can be prevented by avoiding exposure to the viruses or immunization against them.
38.17:
Cancer Prevention
Several factors can increase the risk of cancer in an individual. About 50% of cancer cases can be prevented by adopting a healthy lifestyle, regular exercise, eating healthy, and following a modest cancer prevention diet. Epidemiological studies have consistently shown that populations with vegetable and fruit-rich diets have reduced the incidence of cancer. On the other hand, populations who have a diet rich in animal fat, red meat, junk food, or high calories are predisposed to cancer.
Some naturally occurring phytochemicals such as flavonoids, carotenoids, vitamins, terpenes, sterols, indoles, and phenols have been shown to have anti-cancer properties. The flavonoids and isoflavonoids are secondary plant metabolites and are particularly important in cancer prevention. Flavonoids are found in all terrestrial vascular plants, whereas isoflavonoids are found in legumes, such as soybeans. In general, flavonoids and isoflavonoids prevent cancer development by inhibiting the cell cycle and abnormal cell proliferation, reducing oxidative stress and inducing detoxification enzymes, stimulating the immune system, and apoptosis.
Regular physical activity also helps to reduce the incidence of several types of cancer, including cancers of the colon and breast. Regular exercise increases the movement of food through the intestine, thereby reducing the length of time the bowel lining is exposed to a mutagen. Similarly, rigorous physical activity may decrease the exposure of breast tissue to circulating estrogen, thus reducing the risk of breast cancer.
Besides, daily exercise and a balanced diet can help control excessive weight gain or obesity, which is associated with an increased risk of cancer of the breast, endometrium, gallbladder, pancreas, kidney, adenocarcinoma, and esophagus.
Suggested Reading
- Birt, Diane F., Suzanne Hendrich, and Weiqun Wang. "Dietary agents in cancer prevention: flavonoids and isoflavonoids." Pharmacology & therapeutics 90, no. 2-3 (2001): 157-177.
- Kushi, Lawrence H., Colleen Doyle, Marji McCullough, Cheryl L. Rock, Wendy Demark‐Wahnefried, Elisa V. Bandera, Susan Gapstur et al. "American Cancer Society Guidelines on nutrition and physical activity for cancer prevention: reducing the risk of cancer with healthy food choices and physical activity." CA: a cancer journal for clinicians 62, no. 1 (2012): 30-67.