Countless diseases affect people all over the world today; however, cancer is among the most feared. But despite a wealth of scientific data, most people remain unaware of how they can reduce their risk of developing cancer. According to the National Cancer Institute, as much as 80 percent of all cancers are due to identified factors, and thus are potentially preventable. Thirty percent are due to tobacco use, and as much as 35 percent to 50 percent are due to foods. It is easy to control these and other risk factors.
What Is Cancer:
Cancer starts when one cell begins to multiply out of control. It begins to expand into a lump that can invade healthy tissues and spread to other parts of the body. Carcinogens are substances that promote the development of cancerous cells. They may come from foods, from the air, or even from within the body. Most carcinogens are neutralized before damage can occur, but sometimes they attack the cell’s genetic material (DNA) and alter it. It takes years for a noticeable tumor to develop. During this time, compounds known as inhibitors can keep the cells from growing. Some vitamins in plant foods are known to be inhibitors. Dietary fat, on the other hand, is known to be a promoter that helps the abnormal cells grow quickly.
Factors for Cancer:
Eighty percent of cancers are due to factors that have been identified and can potentially be controlled, according to the National Cancer Institute. Not only can we potentially prevent most cancers, we can also improve the survival rates of people who have cancer.
Thirty percent of cancers are caused by tobacco. Lung cancer is the most obvious example, but by no means the only one. Cancers of the mouth, throat, kidney, and bladder are also caused by tobacco.
Dietary factors also play a significant role in cancer risk. At least one-third of annual cancer deaths in the U.S. are due to dietary factors. A recent review on diet and cancer estimates that up to 80 percent of cancers of the large bowel, breast, and prostate are due to dietary factors (American Cancer Society).
In addition to tobacco use and diet, other factors, including physical activity, reproductive and sexual behavior, bacterial and viral infections, and exposure to radiation and chemicals, may also contribute to the risk of certain forms of cancer.
Estimated Percentages of Cancer Due to Selected Factors*
|Diet||35% to 60%|
|Air and Water Pollution||5%|
Animal Products as a Cause:
Two themes consistently emerge from studies of cancer from many sites: vegetables and fruits help to reduce risk, while meat, animal products, and other fatty foods are frequently found to increase risk. Consumption of dietary fat drives production of hormones, which, in turn, promotes growth of cancer cells in hormone-sensitive organs such as the breast and prostate. Meat is devoid of the protective effects of fiber, antioxidants, phytochemicals, and other helpful nutrients, and it contains high concentrations of saturated fat and potentially carcinogenic compounds, which may increase one’s risk of developing many different kinds of cancer.
Vegetarian diets and diets rich in high-fiber plant foods such as whole grains, legumes, vegetables, and fruits offer a measure of protection. Fiber greatly speeds the passage of food through the colon, effectively removing carcinogens, and fiber actually changes the type of bacteria that is present in the intestine, so there is reduced production of carcinogenic secondary bile acids. Plant foods are also naturally low in fat and rich in antioxidants and other anti-cancer compounds. Not surprisingly, vegetarians are at the lowest risk for cancer and have a significantly reduced risk compared to meat-eaters.
The World Health Organization has determined that dietary factors account for at least 30 percent of all cancers in Western countries and up to 20 percent in developing countries. When cancer researchers started to search for links between diet and cancer, one of the most noticeable findings was that people who avoided meat were much less likely to develop the disease. Large studies in England and Germany showed that vegetarians were about 40 percent less likely to develop cancer compared to meat eaters. In the United States, researchers studied Seventh-day Adventists, a religious group that is remarkable because, although nearly all members avoid tobacco and alcohol and follow generally healthful lifestyles, about half of the Adventist population is vegetarian, while the other half consumes modest amounts of meat. This fact allowed scientists to separate the effects of eating meat from other factors. Overall, these studies showed significant reductions in cancer risk among those who avoided meat all together. In contrast, Harvard studies showed that daily meat eaters have approximately three times the colon cancer risk, compared to those who rarely eat meat.
In 2007, the American Institute for Cancer Research (AICR) published their second review of the major studies on food, nutrition, and cancer prevention. For cancers of the oesophagus, lung, pancreas, stomach, collorectum, endometrium, and prostate, it was determined that red meat (beef, pork, or lamb) and processed meat consumption increased cancer risk. For colorectal cancer, a review of the literature determined that there is convincing scientific evidence that red meat increased cancer risk and that processed meat, saturated/animal fat, and heavily cooked meat were also convincing of increased risk.
Help Prevent Cancer:
A cancer prevention diet is one that is high in fiber, low in fat (especially animal fat), and includes generous portions of fruits and vegetables. It also minimizes or excludes alcohol. The best diets are purely vegan.
All the evidence points to a low-fat, high-fiber diet that includes a variety of fruits, vegetables, whole grains, and beans, as being the best for cancer prevention. Not surprisingly, vegetarians, whose diets easily meet these requirements, are at the lowest risk for cancer. Vegetarians have about half the cancer risk of meat-eaters.
Vegetarians have higher blood levels of beta-carotene. They consume more vitamin C, beta-carotene, indoles, and fiber than meat-eaters. Vegetarians also have stronger immune systems. German researchers recently discovered that vegetarians have more than twice the natural killer cell activity of meat-eaters. Natural killer cells are specialized white blood cells that attack and neutralize cancer cells. Also, vegetarians tend to eat more soy products than meat-eaters. Soybeans contain many substances that are anticarcinogens, including lignans and phytoestrogens. A diet that is rich in soybeans may be one reason for the lower incidence of breast cancer in Asia.
*The website The Cancer Project was a tremendous asset in completing this article.