Lifestyle and cancer
Personal factors that may contribute to the prevention or the development of cancer. The most significant lifestyle factors related to cancer are smoking, diet, OBESITY, and exposure to environmental carcinogens.
Smoking and Other Tobacco Use
Cigarette smoking accounts for 87 percent of LUNG CANCER in the United States, making lung cancer one of the most preventable types of cancer. Cigarette smoking also raises the risk for numerous other types of cancer, including oral cancer, laryngeal cancer, ESOPHAGEAL CANCER, STOMACH CANCER, LIVER CANCER, COLORECTAL CANCER, PANCREATIC CANCER, kidney cancer, BLADDER CANCER, PROSTATE CANCER, BREAST CANCER, and CERVICAL CANCER. Cigar smoking increases the risk for oral cancers (cancers of the MOUTH and lips) as well as lung cancer, pharyngeal cancer, and stomach cancer. Other tobacco use, such as chewing tobacco and snuff, is the primary cause of oral cancers. Not using any form of tobacco removes its risk as a cause of cancer.
Diet and Nutrition
Numerous studies indicate a diet high in fruits, vegetables, and whole grains and whole grain products reduces the risk for most cancers overall and specifically for esophageal cancer, stomach cancer, and colorectal cancer. Researchers believe the NUTRIENTS, antioxidants, and fiber are the key substances that lower cancer risk. Nutrients and antioxidants boost the IMMUNE SYSTEM, improving its ability to detect and eliminate abnormal cells early in their development. Fiber helps absorb toxins in the gastrointestinal tract and move them more rapidly through the digestive process.
Conversely, research demonstrates that a diet high in red meat increases the risk for cancer overall and specifically HORMONE-DRIVEN CANCERS and cancers of the gastrointestinal tract. Red meat is the primary dietary source of saturated fats, which the body uses to synthesize (make) steroid hormones (androgens and estrogens). These hormones fuel the growth of some types of cancer cells in breast cancer, OVARIAN CANCER, ENDOMETRIAL CANCER, and prostate cancer. Whether they may also encourage the development of these cancers remains under investigation.
Some research has established a connection between the length of time food remains in the gastrointestinal tract with the risk for colorectal cancer. A diet high in plant-based, high-fiber foods moves through the digestive process more quickly than a diet high in fat. Some studies show a primarily plant-based diet may move through the body in 6 to 8 hours, while a high-fat, low-fiber diet may take as long as 26 hours to make the digestive journey.
Obesity
The risk for numerous cancers rises with OBESITY. The reasons for this are difficult to separate out. Researchers know that regular physical activity and nutritious EATING HABITS support the health of cells throughout the body as well as foster efficient immune function. These factors are generally lacking in obesity. Further, the increase in adipose tissue prevalent in obesity appears to be a contributing factor to hormone-driven cancers such as prostate cancer and breast cancer, the risks for which are higher in people who have obesity than in people who are of healthy weight.
Exposure to Environmental Carcinogens
Researchers have identified more than a thousand chemicals and other substances that have the ability to cause cancer. Some become hazardous only with repeated excessive exposure over time, and some have a fairly immediate consequence. Chemical exposures are common causes of THYROID CANCER, LEUKEMIA, and LYMPHOMA. The ultraviolet rays of sunlight are perhaps the most common long-term environmental CARCINOGEN, responsible for nearly all SKIN CANCER. Radon, which is present in the soil as a byproduct of deteriorating uranium and other radioactive minerals that occur naturally, is the second-leading cause of lung cancer. RADIATION THERAPY as treatment for cancer is also a carcinogen, raising the risk for lymphoma as well as solid tumors.
Lifestyle Modifications to Decrease Cancer Risk
Nutritious eating habits, daily physical exercise, and avoidance of tobacco products are key ways in which people can modify their lifestyles to reduce the risk for cancer as well as other significant health conditions such as CARDIOVASCULAR DISEASE (CVD) and DIABETES. Health experts recommend that all homes be tested for radon levels, as basements and foundations can trap radon that emerges from the underlying soil. There are ways to release trapped radon so it does not present a cancer risk. ROUTINE MEDICAL EXAMINATION helps detect precancerous conditions and cancer when it is in its early, treatable stages.
See also CANCER PREVENTION; CANCER RISK FACTORS; DIET AND CANCER; HEALTH RISK FACTORS; RADON EXPOSURE; SMOKING AND CANCER; WEIGHT LOSS AND WEIGHT MANAGEMENT.
