As cancer can be a disease related to lifestyle, prevention is the primary goal in reducing cancer. Cigarette smoking is associated with a number of factors, and is universally acknowledged to be the leading cause of lung cancer, worldwide. By far the most important way to reduce the risk of lung cancer is to not smoke. Even exposure to passive smoke can significantly increase the risk of lung cancer. Other inhaled pollutant are associated with cancers, it is advised to use air filters when exposed to diesel exhaust, pitch and tar, dioxin, arsenic, chromium, cadmium, and nickel compounds and asbestos.
Radon exposure has been reported to contribute to the risk of lung cancer in the general population. Radon, a natural radioactive substance, can leak into basements from the surrounding soil. Radon exposure can also occur from the water system of houses, particularly when people take showers. Radon testing is available and advised for those who think their house may be at risk.
Excessive alcohol consumption significantly increases the risk of cancers of the mouth (oral/oropharyngeal cancer), throat (esophageal cancer), voice box (laryngeal cancer), and the risk of liver cancer is well documented. While moderate consumption of alcohol (which is one to two glasses of wine; one beer; or one ounce of spirits a day) is considered to have little impact on cancer, anything above that amount greatly increases the risk. Some people are also poor metabolizers of alcohol, which can increase the risk of liver cancer by the incomplete breakdown of alcohol into highly reactive compounds like acetaldehyde, which can damage DNA.
Whole grains (such as rye, brown rice, and whole wheat) contain high amounts of insoluble fibre which may help protect against a variety of cancers. Consuming a diet high in insoluble fibre is best achieved by switching from white rice to brown rice and from bakery goods and pastas made with white flour or mixed flours to 100% whole wheat bread and whole rye crackers. Refined white flour is generally listed on food packaging labels as ‘flour’, ‘enriched flour’, ‘unbleached flour’, ‘durum wheat’ ‘semolina’ or ‘white flour’. Breads containing only whole wheat are often labelled 100% whole wheat.
Consumption of fruits and vegetables is widely accepted as an important factor in lowering the risk of most common cancers. Many doctors recommend that people wishing to reduce their risk of cancer eat several pieces of fruit and several portions of vegetables every day. Tomatoes may have particular cancer inhibiting properties as they contain lycopene, an antioxidant similar in structure to beta-carotene.
Most lycopene in our diet comes from tomatoes, though traces of lycopene exist in other foods. Evidence of a protective effect for tomato consumption was strongest for cancers of the prostate, lung, and stomach, but some evidence of a protective effect also appeared for cancers of the pancreas, colon, rectum, oesophagus (throat), mouth, breast, and cervix. Cruciferous vegetables from cabbage, Brussels sprouts, broccoli, and cauliflower belong to the brassica family of vegetables. These foods have been associated with anticancer activity, possibly due to several sulphur containing substances found in these foods. Flavonoids are found in virtually all herbs and plant foods. Consumption of flavonoid-rich onions and apples contain large amounts of one flavonoid called quercetin. Quercetin may reduce the spread of some cancers.
People that practice vegetarianism have a lower risk of cancer, mainly because foods, such as the high fruit and vegetable content, consumed by vegetarians may protect against cancer and eating meat may increase the risk of cancer. Animal products contain high amounts of saturated fat which is associated with an increase in ovarian and uterine cancers. Animal products also contain exogenous hormones, many that act similar to estrogen in the body, which may be why female vegetarians have been reported to have lower estrogen levels compared with meat-eating women, possibly explaining a lower incidence of uterine and breast cancers.
The polyunsaturated omega 3 fatty acid found in fish reduces the risk of cancer by suppressing free radical reactive nitrogen species, reactive oxygen species, and free radicals which are implicated in tumour progression.