Certain lifestyle factors can increase a person’s risk of developing cancer. The term lifestyle factor refers to an individual’s behaviors and habits. Eating a vegetarian diet and exercising daily are lifestyle factors. More than 70 percent of cancers may be linked to lifestyle factors. Therefore, individuals can often prevent cancer by changing unhealthy lifestyle choices. Lifestyle factors that increase cancer risk include:

• Tobacco use. According to the American Cancer Society (ACS), cigarette smoking causes approximately 87 percent of lung cancer deaths and at least 30 percent of all cancer deaths. The use of cigarettes and other tobacco products has been linked to cancers of the pancreas, bladder, liver, kidney, stomach, uterine cervix, rectum, colon and some leukemias. Tobacco products such as cigarettes, cigars, pipe and smokeless tobacco and snuff have more than 60 compounds that are cancer-causing agents (carcinogens). The most important action a person can take  to reduce his or her cancer risk is to quit (or never begin) smoking.
  
  
• Alcohol consumption. Many cancers may be prevented by limiting the consumption of alcohol. Heavy alcohol consumption has been associated with cancers of the breast, liver, esophagus, larynx (voice box), pharynx (throat) and mouth. The ACS recommends that women consume no more than one alcoholic drink per day and men consume no more than two alcoholic drinks per day. A drink is defined as:
  
• • 12 ounces (0.35 liters) of beer
  • 5 ounces (0.15 liters) of wine
  • 1.5 ounces (0.04 liters) of distilled spirits (80 proof)
    
    
• Diet. One of the main benefits of good nutrition is that it reduces the risk of various diseases, including certain cancers. According to the ACS, there is a direct link between dietary choices and 30 to 40 percent of cancers. The ACS’s dietary guidelines for cancer prevention recommend that individuals:
  
• • Eat at least five servings of fruits and vegetables every day
    
    
  • Choose whole grains instead of refined (processed) grains and sugars
    
    
  • Limit red meat consumption, especially processed meats and those high in fat
    
    
  • Select foods that help achieve and maintain a healthy weight
    
    
  • Limit salt intake
    
    
  Additionally, safe methods of food preparation, such as baking, poaching or broiling (instead of grilling or frying), may also help prevent cancer.
  
  
• Physical activity. Regular exercise is considered an effective means of preventing cancer in many individuals. The ACS recommends that adults engage in moderate physical activity for at least 30 minutes on five or more days of the week. Moderate or vigorous exercise for a minimum of 45 minutes on five or more days each week may further reduce the likelihood of developing breast or colon cancer. The ACS recommends that children and adolescents engage in at least one hour of moderate-to-vigorous exercise at least five days a week to lower their cancer risk.
  
  
• Sexual activity. Certain kinds of sexual behavior can increase an individual’s risk of developing conditions that may lead to cancer. For instance, having multiple sexual partners and engaging in skin-to-skin contact (unprotected intercourse) can lead to infection with the human papillomavirus (HPV) or the human immunodeficiency virus (HIV). HPV is a risk factor in reproductive cancers, especially cervical cancer in women. It also has been linked to some head and neck cancers, notably of the tonsils. HIV raises the risk of cervical cancer, vulvar cancer, anal cancer and lymphoma, and is believed to increase the risk of testicular and penile cancers. Individuals can therefore help prevent cancer by limiting their number of sexual partners and practicing safe sex. It is important to stress that condoms do not prevent the spread of disease in areas of the skin not covered by the condom. In 2006, the Food and Drug Administration approved the first vaccine that protects against four strains of HPV, two of which cause 70 percent of cervical cancer cases. The vaccine is approved for girls and women ages 9 to 26.
  
  
• Fertility drugs/oral contraceptives. Studies regarding the relationship between fertility drugs and cancer are inconclusive. However, fertility drugs increase a woman’s ovulations as well as the levels of hormones related to ovulation, both of which are suspected to increase the risk of ovarian cancer. Additionally, the use of oral contraceptives (birth control pills) has been linked to an increased risk of cancer, particularly breast cancer. Women who take fertility drugs or oral contraceptives should discuss any concerns, recommendations for monitoring and possible alternatives with their physician.
  
  
• Hormone replacement therapy (HRT). Women may be prescribed HRT to counter some of the symptoms and potential effects of menopause on the body. Though studies are inconclusive, it is suspected that a relationship exists between HRT and increased risk of some forms of cancer, such as breast cancer. However, HRT is also believed to reduce the risk of colorectal cancer and possibly other medical conditions, including osteoporosis and heart disease.  Women who take or plan on taking HRT should discuss their concerns and possible alternatives with their physician. A major report by the Women’s Health Initiative in 2002 indicated there were elevated risks of breast cancer for women who used HRT. Since that time, the level of HRT use has dropped precipitously.
  
  
• Occupational exposures. Some individuals are exposed to carcinogens in the workplace, such as asbestos. Asbestos is a group of fibrous minerals that occurs naturally in the environment and can cause lung and other cancers, especially among people who also smoke. Miners and people in the shipbuilding industry, for instance, may be exposed to this chemical through inhalation of its fibers in the air. Another carcinogen that may affect workers is benzene, a colorless, flammable liquid that may be found in rubber factories and chemical plants. It also may be present in oil refineries and gasoline industries.  
  
  

  

  The Occupational Safety and Health Administration (OSHA) has implemented certain regulations regarding benzene in the workplace. To help prevent cancer from chemical exposure, individuals should use personal protective equipment, such as a respirator, in these industries.
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• Lead exposure. Lead is a metal that occurs naturally in small amounts in the earth. There is some evidence that this metal is carcinogenic. Individuals can help prevent cancer by implementing the following cautionary measures:
  
• • Avoiding lead exposure in the home by using lead–free ceramics, paint and other products and hiring a qualified contractor to remove leaded paint from the home. People who live in homes built before 1980 should determine if their home contains leaded paint.
    
    
  • Remove dust from windowsills, floors and other surfaces with detergent and water. Move playpens and cribs away from areas where paint is chipping or peeling. It is also important to assure that children do not remove chipped paint and place it in their mouths. Children are at risk for neurologic damage from lead.
    
    
  • People who live in buildings with old pipes or water heaters should use cold tap water for drinking and cooking.
    
    
• Ionizing radiation. Radiation is energy emission from any source. Ionizing radiation, a type of high-frequency radiation, has been found to cause cancer in some individuals. People may be exposed to ionizing radiation through certain medical tests, such as x-rays. However, the radiation in medical tests is typically in very small amounts.  Radiation therapy,  on the other hand, is frequently used to treat some types of cancer and involves very high dosages. This treatment can sometimes promote the development of secondary cancers. For most patients, the benefits of radiation therapy outweigh the risks.
  

There has been a great deal of speculation that aspartame, an artificial sweetener used in many diet beverages, is carcinogenic. However, the Food and Drug Administration (FDA), World Heath Organization (WHO) and the Joint Expert Committee of Food Additives of the United Nations Food and Agricultural Organization have all concluded that aspartame does not cause cancer in the general population. Most health experts do not believe that limiting products containing aspartame will help prevent cancer.

There has also been much controversy about whether cellular phone use increases an individual’s cancer risk, especially brain cancer. Because cell phones are a fairly new technology, their impact on health is not yet fully understood. However, most cell phones produce low energy levels and do not emit ionizing radiation. This makes them an unlikely cause of cancer. Limiting cell phone use is not considered a preventive measure for brain tumors or other cancer.