BRIEF NUTRITIONAL FACTS ABOUT CANCER
Introduction and general statement
The concept of nutritional effects on the cause and prevention of cancer is a recent development. However, scientific data have accumulated convincingly to show that the diet is an important factor in the cause and prevention of cancer. The articles appearing in scientific journals in recent times on nutrition and cancer have increased greatly and many more are likely going to be published. This is because the war against cancer is embracing prevention, and the diet has been recognized as an important strategy to combats the scourge of cancer.
However, the data on diet and cancer are largely obtained from epidemiological surveys and most have been best tested on animal models. In spite of this, there are many claims in scientific and common literature on the efficacy of one dietary component or the other as anticancer agents. The medical advice is that whatever will be consumed in the diet as anticancer agents must be strictly done with consultation with your doctor or dietitian and must be done in moderation. This is because most of the so-called chemopreventive agents in the diets have not been fully investigated and information about the efficacy of some them are controversial.
In the present case, we shall discuss in simple terms those that have been consistently reported in scientific literature and we shall refer the inquisitive mind to the research digest on this website and medical journals where appropriate.
Consumption of fiber-rich foods:
Whole Grains, Legumes, Fruits & Vegetables
Consumption of fiber-rich foods like fruits, green vegetables and whole grains has been found to positively impact on some types of cancer especially those that are related to the intestinal tract like colon cancer. Scientist believed that the effects of the dietary fiber depend on its type. However, consumption of fiber-rich foods is known to increase bowel movement and in the process reduces the residence time of whatever carcinogenic materials that might be inadvertently consumed with the foods. The consumption of fiber is not only useful for intestinal cancer patients, but also , it is healthful because dietary predisposing factors can be drastically reduced when whole grains and fiber-rich foods are consumed on daily basis. It is generally believed that the consumption of the equivalent of about 100-250 g of salad 5 fruits (fresh oranges) a day could be useful. However, drinking juice from where most fibers have been extracted is no substitute to consumption of fiber.
Broccoli and cruciferous vegetables
Scientists have found that there are some peculiar active ingredients in the cruciferous seeds and vegetables that may have anticancer effects. These have been variously described in literature and recommendation is that a lavish intake of a mixed-type of vegetables may be beneficial in dietary management for prevention of cancer. The cruciferous vegetable include brussels sprouts, cabbage, kale, turnips, cauliflower and collards all of which have been associated with prevention of carcinogenesis and metastasis.
Ginger, Onion and Garlic
Scientific and folkloric information on the biotherapeutic efficacy of these food supplements is available, and controversy exists on the same subject. However, information on their usefulness seems to be more preponderant than those against. The active ingredients in some of them have been isolated and fed in some experiments giving rise to controversial information. It is generally believed that feeding them wholly seems to be more efficacious that the extraction of the ingredient. Certainly, all these are also vegetables and they contain some quantity of fiber, therefore, it is possible that the constituents are acting synergistically.
Types of fats and oils
Consumption of high fats and oils are generally regarded as predisposing factors to cancer and other ailments. Therefore, the rule of thumb is to reduce consumption of fat to the barest minimum. Consumption of fats and oils and implications on cancer has been an area of active research and controversies. However, it now well recognized that some types of fats and fatty acids might even be useful to prevent cancer, while majority of others should be minimally used to avoid predisposition to cancer.
A type of commonly used fat that has been widely believed to reduce breast cancer and possibly useful to other types is olive oil. Information on this is largely based on epidemiological data of the Mediterranean inhabitants that have low incidence of breast cancer. Olive oil contains monounsaturated fatty acids and it has been found good. It is also believed to have medicinal properties in the folk medicine. Some other oils types have also been found to be useful while some other were not useful. There is argument whether high consumption of fat predisposes cancer or not, however, most epidemiological data and scientific evidences discouraged high fats/oil intake, perhaps because it can predispose some other diseases.
A particular fatty acid that has been recently found to have anticancer activity is called conjugated linoleic acid. It is found in small quantities in milk and meat, but it can be readily synthesized in the laboratory. Many published work on this fatty acids have been consistent and it appears to be have multiple efficacy at very low dietary supplemental concentration, non-toxic and well tolerated. Some companies are already marketing it under different brand names.
Tea and coffee drinking
There are scientific data to support drinking of some types of tea may have anticancer effect. Notable among these types of tea is the black tea, which is known to be more efficacious than the green tea. The active ingredients in the tea have been isolated and there seems to a consensus on their usefulness. Drinking coffee has not been conclusively proven for its anticancer effects, but is it widely believed that its action may be equivocal. It prevents occurrence, and if there is occurrence, it speeds it up. The active ingredient in coffee is caffeine and this is a strongly active compound, which can accelerate many biological reactions.
Mushroom and microbially treated foods
For ages consumption of edible fungi called mushrooms have been honored. It is also scientifically proven that there are some types of unidentified components that are not only nutritionally useful, but healthful and possibly anticarcinogenic. The mushrooms contained in their cell walls some types of carbohydrates (and fiber) that are unique and their consumption could be healthful.
Microbially treated foods are foods that have been wholly or partially subjected to beneficial microbial transformation. Ready examples are cheeses, yogurt, wine, beer, etc. Because centuries of benefits of moderate consumption of "fermented foods" supporting scientific documents have also appeared in literature. Based on available evidence, fermented foods of milk origin are known to be very healthful and some have been found useful as anticancer. Consumption of yogurt has been considered useful as preventive for cancer. The same information has not been made for cheeses, but there is some information that milk fat contains anticarcinogenic compounds like linoleic acid, sphingomyelin, butyric acid and ether lipids, therefore, cheese may be equally good.
Bioactive compounds in vegetables (plants)
Many components of plants are known to be nutritionally useful and some are regarded as antinutrients. However, recent data have recognized some of the antinutrients as having medical importance, and specifically in this case, anticancer effects. Because this is a specialized area, patients are advised to consume whole grains and bother less about what many may call antinutritional factors in them. Normal culinary processing is sufficient for their consumption and their varieties will most likely be more useful.
Partially germinated seeds of many plants are consumed as sprouts and these are known to contain a lot of minerals, vitamins and other useful metabolites, which nutritionists believe could be have anticancer effects. Example of sprouts are brussels, bean, millet, bamboo, etc.
Vitamins with anticancer effects
Some vitamins have been reported to be beneficial in prevention of cancer or reduction if its spreading and, in such cases, a high dosage than is normally recommended for a daily intake is normally taken. However, there is dearth of research data on the exact amount to be taken in such cases. Nonetheless, the advantages of some these will be discussed below.
Vitamin C or Ascorbic Acid.
It has been documented that it has anticarcinogenic properties because it has anti-oxidative properties. Vitamin C prevents oxidative damage involved in the initiation and promotion of carcinogenesis. Vitmain C is an inhibitor of N-nitroso compounds that are carcinogenic and which we sometimes consume with other foods and encountered also from the environment. Many experts believed that a higher intake of this water-soluble vitamin on daily basis is even useful for overall healthfulness of the patient and it is largely available in fruits and vegetables.
Vitamin E is called a-tocopherol and it is also a strong biological antioxidant especially the damaging free radicals, which causes cancer. Scientists have found Vitamin E to exert anticancer properties.
Vitamin A as B-carotene had been found to be to exert anticancer effects and this is largely because it also serves as a natural antioxidant. B-carotene is best metabolized as provitamin A carotenoid and it is abundant in fruits and vegetables. In fact, the name and color of the vitamin mimics carrot.
A vitamin status is yet to be nutritionally ascribed to these compounds called b-17. These are the nitrilosides, a designation proposed to include a large group of water-soluble factors collectively Beta-cyanophoric glycosides. The nitrilosides are found in the seeds of practically all fruits- apples, apricots, cherries, peaches, plums, nectarines, etc. Although the proponents of this vitamin are struggling from doubting experts, however, significant information is available that this vitamin, whose concentration is very low in foods have anticancer and other healthful benefits.
Selenium is an element we consume in trace amount in our diets containing nuts and grains, and it as been found good as an antioxidant. Many studies in anticancer efficacy of selenium have found it preventing or rather prolonging drug resistance in some laboratory-induced cancer. It has also been reported in some studies the direct effect on reduction of cancer spreading (metastasis). Research has also investigated the best form of administering selenium either as simple compound in conjunction with other nutrient(s) or solely as dietary additives, the investigations in this regard are pointing to advantages of simple organic forms of selenium such as selenomethionie.
These are compounds synthesized by plants and their biological functions are not fully understood. They are generally considered as antinutritional and many a times are toxic when consumed by man. However, new frontiers in research have found usefulness for most of these phytochemicals and it is indeed surprising that many of them have anticancer effects. Since they are found in many plants as compounds, and presently regarded as antinutritional despite the emerging usefulness, we shall not discuss them any further.
GENERAL DIETARY & HABIT RECOMMENDATION TO REDUCE CANCER INCIDENCE AND SEVERITY
- An increase of about 65% of the intake of vegetables and fruits will greatly reduce the incidence of cancer.
- Reduction in consumption of high fat and protein diets and alcohol will positively influence cancer incidence.
- The consumption of healthy diets with maintenance of physical activity and appropriate body mass, can reduce cancer incidence by 30-40%.
- In the US, the effort to decrease cancer risk among the population, national health objectives for the year 2000 included recommendations to decrease intake of dietary fat and alcohol and increase intake of fruits, vegetables, and grains.
Advisor Nutritional Code for Cancer Prevention
The National Science and Technology Council Committee on Health, safety and Food identified nutrition as pivotal in optimizing health and productivity and in reducing the risk of disease-related diseases including cancer.