NFS: Nutritional Toxicology - Research Paper Example

NFS: Nutritional Toxicology I. Introduction 1 Nutritional Toxicology Nutritional toxicology is the “science of dietray toxins and their relationship in nutrition as mode of action and metabolism of toxic compounds that occur in food, feeds and plants (Nutritional Toxicology).” Toxic compounds or toxins within the diet is due to the excess ingestion or intake of vitamins and minerals, which causes alteration in the chemical symbiosis or exchange within the human body that affects digestion, absorption, transport, metabolism and excretion (Jin, U O, page 1). 1.2 Vitamin and Mineral Toxicity Vitamins and minerals are needed to maintain good health, however, some vitamins, vitamin A and D in particular when taken in large doses, could cause significant changes in the human body. These changes may be attributed to the fact that vitamins A and D are absorbed within the cells and are not excreted or eliminated from the system. Minerals, major and trace elements, could also cause poisoning when taken in excess. And this is true with niacin, ascrobic acid, sodium, etc. Vitamin and mineral toxicity produces significant changes in the entire wellbeing of the person. When there is too much intake of vitamin A the results or symptoms manifested would be: swelling over long bones, dry and itching skin, nausea and diarrhea, fragile or brittle bones, fatigue or lethargy, bone and or joint pains, fetus and spontaneous abortion. The recommended daily allowance fro vitamin A is 2400 IU for women and 3000 IU for men. Children must also be supervised with regards to vitamin A intake to avoid loss of appetite, itching, irritability, swelling and tenderness of bone and failure to gain weight. The recommended daily intake for vitamin D should range from 100 IU per day for adults and10 micrograms per day for infants of 400 IU. Toxicity from excess intake of vitamin D results in the deposition of calcium and phosphorus in the soft tissues of the body, thus damaging the heart, blood vessels and kidneys Niacin a water soluble vitamin has no toxic effects when taken with natural foods, however, when used at supermega dose levels the results would be flusihing or red skin, uticaria, heartburn and nausea. The required intake of this vitamin should be limited to 5 to 20 mg per day. Phosphorus when taken excessively can result to the depletion of body calcium which would eventuallylead to jaw erosion. The recommended RDA for men and women is 1200 mg per day. Food sources for phsophorus are milk, chees, yogurt, meat, poultry, grains, and fish. Potassium is needed for fluid balance, nerve transmission and acid base balance. Overdose of potasssium leads to cardiac arrythmias if there is poor kidney function. Food sources includes leafy vegetables, beans, potatoes, bananan, milk, meats, coffee and tea. The RDA for both men and women should be 2000mg per day. Sodium is another major mineral which when taken in excess of its required RDA of 1100 to 3300 mg for men and women daily will result to high blood pressure. The common source of this minneral is table salt. Chlorine is important for extra cellular processes that when taken excessively would result to high blood pressure. The RDA for chlorine is 700 mg daily for men and women. Food sources for this mineral is fruits and vegetables. Magnesium has an RDA of 10 mg for men and 15 mg for women. Dietary sources are eggs, lean meats, legumes, whole grains and green and leafy vegetables. Too much intake of magnesium causes diarrhea. The preceding information about vitamins and minerals goes to show that the required daily allowance must be followed because the excess and deficiency of the diet in relation to vitamins and minerals alters the normal bodily functions. It may also be good to know that food from plants and animals contains contaminants that came by naturally or through the manufacturing stage. Contaminants causes microorganisms or toxins that infect food. Once the food is inhabited by toxins, it may lead to lethal intoxicatyions when ingested. The microorganisms from the aforementioned contaminants could enter the food chain at any stage of the food cycle. So proper care in handling of food from source to the table must always be observed to reduce the possibility of contaminants. 1.3 Nitrosamines in Relation to Nutritional Toxicology Nitrosamines “are a group of chemicals that have caused cancer in some animals within laboratory conditions (Nitrosamines-MSN Encarta, page 1).” Nitrosamine is the combination of nitrite with the natural amines which are naturally found in food or the human body (stomach). Nitrite, which is a form of nitrosamine, is used to cure and preserve food and meat products. In connection to nutritional toxicology, excess or large doses of ingested food and beverages that contain nitrite will lead to poisoning and alteration of the chemical exchanges within the human body. Although not proven to cause cancer in humans, the use of nitrite on manufactured and preserved foods and beverages has been significantly reduced when said chemical was found in fried bacon. Further study was made which suggested that nitrite was cacinogenic or contributing to the cause of cancer, however, since this was not likewise proven, the FDA and USDA did not ban it from the market (Nitrosamines, MSN-Encarta, page 1). II. Nitrosamines and Cancer 2.1 Terms and Definitions (Your Dictionary.com): 1. Amine – a derivative or ammonia in which hydrogen atoms have been replaced by non-acidic radicals containing hydrogen and carbon atoms. 2. Botulism – poisoning resulting fron the toxin produced by botulinus bacteria, sometimes found in foods improperly canned or preserved; characterized by muscular paralysis and breathing which is often fatal. 3. Cancer – a malignant new growth anywhere in the body of a person or an animal. Any of various diseases characterized by the uncontrolled growth of cells that disrupt body tissue, metabolism, etc. 4. Carcinogen – any substance that produces cancer. 5. Intoxication – poisoning or becoming poisoned as by drug or serum, etc. 6. Metabolism – the chemical and physical process continuously going on in living organism and cells consisting of anabolism and catabolism. 7. Nitrite – a salt of nitrous acid containing the monovalent negative radical NO. 8. Isomer – any of two or more chmical compounds have the same constituent elements in the same proportion by weight but differeing in physical or chemical properties because of differences in the structure of their molecules. 9. Toxin – any various poisonous compounds produced by some mircroorganism and causing certain diseases. 2.2 Nitrosamine Formation Nitrosamines are chemical compounds of the chemical structure R1N(-R2)-N = O, some of which are carcinogenic . These compounds are produced from nitrites and secondary amines which often occur in the form of proteins. Their formation can only happened under certain conditions including strongly acidic environments such as that of the stomach; and high temperatures, as in frying which enhances the formation of nitrosamines (Nitrosamine, Wikipedia). 2.3 Studies and Experiments Done on Nitrosamines The following are experiments and studies made on nitrosamine according to the research of Richard A. Scanlan, Ph. D.: a) In 1956 two British scieitist, John Barnes and Peter Magee reported that dimethynitrosamin caused liver tumors in rats being observed in the laboratory. Their discovery was made when a routine screening of chemicals used as solvents for the dry cleaning industry was being proposed. b) After Barnes and Magees discovery of the lethal properties of dimethylnitrosamine, scientits aorund the world made a thorough study of nitrosamine and the N-nitroso compounds. Ninety percent (90%) of the compounds which were tested were discovered to be carcinogenic or cancer causing. Most nitrosamines they discovered causes changes or variations in the natural characteristics of germ cells in plants and animals. These changes propagates cancer in the lungs, liver and other major organs in the experimental animals. The chemical and physical processes of nitrosamine in the human body and animal tissues are the same, so the possibility of people contracting cancer through the carcinogenic properties of nitrosamines is a big possibility. c) In the 1970s, intensive investigations revealed that large amounts of sodium nitrite were added as preservatives for animal feeds, in particular the herring meal, which were given to the livestocks in Norway that caused liver disorders and cancer among the animals. It was also discovered that dimethylnitrosamine was also present in the feeds, the same chemical compound found by Barnes and magee years before to have caused the liver cancer in live rats. The dimethylnitrosamine found in the above mentioned herring meal was the result of a chemical reaction beteen dimethylamine (a common amine found in fish meals) and a nitrosating agent from sodium nitrite which was used as the preservative. Due to the above findings on the carcinogenic properties of nitrosamines, questions were raised whether nitrosamines could also form or occur within human food. It is essential to remember that amines occur naturally – meaning they are naturally present in plants and animals. And since sodium nitrite is used to preserve food and cure meats for human consumption and also to prevent botulism, foods and beverages could likewise be susceptible. Removal of sodium nitrite might prevent nitrosamine formation but increases the chances of botulism poisoning. The solution presented was to limit sodium nitrite addition to the lowest level that is likewise effective in the production of Clotridium Botulinum (cause of botulism. 2.4 Nitrosamines in Relation to Ascorbic Acid, Erythorbic Acid and Vitamin E In 1970 research in the prevention and reduction of sodium nitrite as a preservative or food additive was productive. Experiments showed that addition of ascorbic acid or vitamin C in cured or preserved meats hinders the formation of nitrosamine. However, most meat manufacturers turned to using erythorbic acid ( isomer of ascorbic acid or vitamin C) and was likewise found to be as effective as vitamin C and a lot cheaper. Alpha-tocopherol or vitamin E also prevents nitrosamine formation. The result of adding ascorbic acid/vitamin C, erythorbic acid and alphatocopherol/vitamin E has significantly reduced the level of nitrosamines in cured meats because of their anti-oxidant properties that nullifies nitrosamine formation. 2.5 Sources of Nitrosamine and Level of Exposure Nitrosamines could be found in many food sources like beer, fish, fish by products, cured/preserved meats and cheese products which are preserved by nitrite pickling salt. Limist were established on the amount of nitrites used in meat products to reduce risks of cancer. Rules about the addition of ascorbic acid or vitamin C and other related elements or compounds to repress the formation of nitrosamine were implemented. Reports from the National Academy of Sciences (NAS) estimated that “per capita exposure is about one (1) microgram per day from foods and beverages, especially from fried bacon and beer.” The exposure for smokers is 17 micrograms per day which is lowered a little by using cigarette filters. At present, reports indicate that industrial exposure, found in a rubber or chemical plant could be higher (Scanlan). III. Conclusion Toxicants can interfere with the intake digestion, absorption, function, metabolism of nutrients. The following effects of toxicants in the diet must be considered (Jin U O). 1. Modification of Nutrient Content of Foods Before actually trying to change or modify a prescribed diet especially for sick people doctors and dieticians must be consulted to know whether the food has the required nutritional value to keep the person healthy and be able to do his or her daily activities. 2. Modulation of Appetite Toxicants in food may decrease food intake. It also affects the regular metabolism of the body which could cause system or organ defects. So it is advisable to be able to eat food at a moderate pace and at moderate quantities. 3. Inhibition of Digestion and Absorption Most toxicants in food affects normal digest and absorption. Once digestion is hindered the normal metabolism and asbsoprtion of required nutrients would also be inhibited, thus, affecting the normal body processes. 4. Alteration of Digestion and Absorption The interference of toxins within the human body affects metabolic activities of absorption and digestion. Digestion and absorption when affected by toxicants will bealso affect other processes like normal elimination and excretion. When these happens the sythesis of nutrients needed by the body will be depleted. Indirect evidence points out that nitrosamines are human carcinogens. This assumption may be based on the relation of chemical carcinogens in tobacco products and lung cancer. However it is difficult to know the actual minute daily exposure from foods and beverages (Scanlan). Inorder to reduce or limit ones exposure to the harmful effects of nitrosamines, the following suggestions should be considered (Justin): 1. Limit intake of cured or preserved meats. 2. Avoid or quit smoking to prevent lung cancer. 3. Reduce or avoid places where factories for rubber and metal are present. Nutritional toxicology and nitrosamines are part of the overall nutritional and dietary needs of the human body. Since both are interrelated, the significance of excessive intake of food and supplements in relation to ones health must be critically observed. While its true that we need to eat to stay healthy it is equally important to know how much we should eat and the contents or ingredients of the food we are eating. Our exposure to the environment also affects our health and it is imperative that we should limit our exposure to radical elements that would make us ill in the long run. Prevention is alway better than cure, so it is always best to be cautious when it come to our personal well being in terms of the food we put on the table and other aspects. References Justin, Thomas. (2006) Nitrosamines and Their Potential Health Effects. Retrieved on April 9, 2008 from http://www.geocites.com/bcjungmph/thomas.pdf Nutritional Toxicology (35.253) – 1.5 CH. (n.d.) Retrieved on April 8, 2008 from http://www.umanitoba.ca/afs/animal_science/programs/co/ko_065-219.doc O, Jin U. Nutritional ToxicologyScience, University of Massachusetts at Amherst. Retireved on April 8, 2008 from http://www-unix.oit.umass.edu/~excs597k/uo/nutr.htm Scanlan, Richard A. Ph. D. (2000) Nitrosamine and Cancer. Retrieved on April 9, 2008 from http://lpi.oregonstate.edu/f-w00/nitrosamine.html Wikipedia, the free encyclopedia. (n.d.) Retrieved on April 9, 2008 from http://en.wikipedia.org/wiki/Nitrosamine Your Dictionary.com. Retrieved on April 9, 2008 from http://www.yourdictionary.com Read More