Optimum Nutrition And Digestive Wellness - Case Study Example

Nutrition The process of digestion begins with food intake through the mouth. In the human stomach the chief visible change through the bullet hole in the stomach of Alexis St. Martin, is that food proteins which enter as insoluble matter, such as meat or coagulated egg white, are dissolved (see appendix 1). The long protein chains are involved and broken into short chains. No absorption of the products occurs in the stomach; absorption begins only after the chyme enters the intestine. In the intestine the chyme meets the enzymes secreted by the pancreas and the intestinal wall (Holford 2005). These enzymes hydrolyze the long peptides of the chyme to short peptides containing only 2 or 3 amino acids. Any unaffected protein particles that have escaped the gastric juice are digested. The ability of the intestine to digest, not only gastric peptides, but also intact proteins, makes possible the nutrition of people with achylia gastrica and even of persons who have had the stomach completely removed. The soluble digestive products then diffuse into the bacterial cell and are used. Protozoa usually sweep food particles and water into their bodies, at a fixed or a changed position; and these food vacuoles constitute temporary "stomachs" in which the digestion proceeds. Metazoa have permanent digestive organs, most elaborate in the mammals. Man's digestive system, or alimentary canal, is a continuous passage through the body, from mouth to anus, with special extensions into accessory secreting organs (glands) (Lipski, 2004). 2. Whenever an organism consumes food in the solid state, this must be brought into solution before it can be utilized. It is necessary, therefore, that such solid food be digested. In some organisms digestion may occur outside of the body, and this may constitute an important adaptation for those animals which are in the habit of eating animals larger than themselves (Lipski, 2004). Ordinarily, however, food is taken into the body and digested there. Digestion may occur in cavities of special organs such as the stomach or intestine, or it may occur within the protoplasm of cells. The latter type of digestion obviously takes place in protozoa. In organisms such as paramecium or ameba the ingested food is enclosed in a food vacuole, which serves the same purpose as the stomach or intestine of a complicated metazoan. Within the food vacuole the solid food particle is brought into solution. It must not be thought, however, that intracellular digestion is confined to protozoa. Moreover, in some animals rather higher in the evolutionary scale, there is also a certain amount of intracellular digestion (Holford 2005). These phagocytic cells even enter into the lumen of the stomach or intestine, ingest particles of food there and then carry these food particles back into the tissues and digest them there. Such intracellular digestion, however, is a primitive character and it does not occur to any extent in higher animals such as the insects and vertebrates. In the conversion of solid food to a state of solution, enzymes play the leading role. It will be necessary, therefore, to consider the subject of enzymes and the nature of enzyme action. It should be strongly emphasized, however, that enzymes are not concerned only with digestion, but that they are essential factors in all of the chemical activities of the organism (Lipski, 2004). The living organism is essentially a chemical engine, dependent for its growth, maintenance and energy on chemical reactions. These reactions are controlled by catalysts. One of the most striking achievements of modern biology and biological chemistry is the isolation of more and more of these catalysts so important for the vital process. Once isolated, it is possible to study their behavior in test tubes or other suitable containers. In other words, one can detach from the living material certain non-living substances capable of causing or promoting the complex chemical transformations which constitute a major part of the mystery of protoplasm. The substance acted upon by an enzyme is called its substrate. In designating a particular enzyme, the suffixase is added to the name of the substrate. However, older names, such as pepsin or rennin, are retained. The suffixlytic is used to denote enzyme activity on classes of substances. Thus, proteolytic enzymes act on proteins, and lipolytic enzymes act on fats or lipids (Lipski, 2004). 3. Living substance contains three main types of organic constituents. Of these the proteins and carbohydrates are typically water-soluble substances. It is true that some proteins and some carbohydrates are not soluble in water or in dilute salt solutions, but insoluble proteins are relatively rare, and insoluble carbohydrates are easily broken down to soluble compounds. On the other hand, the third class of substances characteristic of protoplasm is distinguished by a thorough-going insolubility in water. Indeed, all protoplasmic constituents not soluble in water, but soluble in fat solvents, are grouped together as lipids (Nichols and Faass 1999). The term "lipids" can then be taken to include, first, the true fats, secondly the phosphatids which are compounds of fatty acid, phosphoric acid, and organic base, and, thirdly, the sterols. The latter bear no chemical kinship to the fats, but resemble them in being insoluble in water but soluble in ether. Although not so abundant in living material as are the proteins, the lipids are indispensable for life. Insoluble in water, they are nevertheless finely dispersed in the watery protoplasm. This is in part due to the fact that the lipids are emulsified; in part, also, to the fact that the lipids may combine with proteins to form water-soluble compounds. The nature of these compounds is not at all well known, but it seems certain, as already noted, that they do occur in protoplasm (Lipski, 2004). 4. Positive energy balance occurs when energy intake is greater than energy expenditure and promotes weight gain. Conversely, negative energy balance promotes a decrease in body fat stores and weight loss. Body weight is regulated by a series of physiological processes which have the capacity to maintain weight within a relatively narrow range (stable weight). Traditional dietary management centres on educating patients about healthier food choices and persuading them that such changes to lifestyle are important. However, it is now recognized that simply providing nutrition education or 'prescribing' a diet is inadequate and in recent years there has been greater focus on the need to combine nutrition information with behavioural techniques. As weight management strategies have moved away from achieving ideal body weight towards moderate weight loss, and maintenance of this loss, so emphasis in dietary management has changed from very severe energy restrictions towards modest, staged changes which are more feasible to maintain long term. The practice of advising a fixed energy allowance, for example 1200 kcal/day, to all obese individuals has been subject to some criticism (Sakurai 2000). The more obese the person, the higher their energy requirements and the greater the energy deficit imposed, so the more likely the person is to struggle with such drastic food changes. It has been demonstrated that compliance to dietary advice and sustained weight loss are improved with a modest deficit of 500kcal per day (from energy requirements) compared to very severe energy restriction. Fat appears to exert its greatest influence on energy balance through its effects on appetite. In studies where people have been allowed to eat as much as they like, the same quantity of food is generally eaten with high fat as with high carbohydrate meals, but because fat gram for gram contains more than twice the number of calories as carbohydrate, considerably more calories are consumed. Carbohydrate is known to have a greater satiating effect than fat and its intake is quite closely regulated by the body. Whether the type of carbohydrate influences energy balance has been subject to some debate. The energy density (calories per unit weight) of carbohydrate varies depending on the type of carbohydrate, for example bread has a lower energy density than sugar. Evidence is beginning to emerge which supports the theory that low energy density carbohydrates tend to result in lower energy intakes than high energy density carbohydrates, so supporting the increased consumption of high fibre starchy carbohydrates rather than simple sugars to replace fats. Fruits and vegetables are naturally low in fat, high in fibre and are rich sources of vitamins and minerals, particularly antioxidant nutrients such as vitamin C, beta-carotene, selenium and others such as lycopene (Nichols and Faass 1999). Diabetes is a metabolism disordered characterized by high blood sugar level (Scheen 2000). The strong relationship between the risk of type diabetes, on the one hand, and body mass index (BMI) or weight gain, on the other hand, has been demonstrated in several studies including both men and women. Besides the degree of obesity per se, several other factors obviously play a crucial role such as the abdominal distribution of adiposity and the duration of overweight Everybody agrees upon the fact that lifestyle modification is the cornerstone of the treatment of obese subjects with type 2 diabetes. Initial recommendations to any obese diabetic patient should thus include optimization of the meal plan and enhancement of physical activity. In case of failure of conservative treatment, which unfortunately is very common, pharmacological approaches should be considered, targeting weight excess (anti-obesity agents), hyperglycaemia (anti-diabetic drugs) or both. Attention should also be paid to the appropriate management of other risk factors frequently associated with obesity and type 2 diabetes, such as arterial hypertension and dyslipidaemias, in order to improve the poor cardiovascular prognosis of such patients. Finally, when all medical approaches have failed, anti-obesity surgery may be considered in severely obese well selected diabetic patients. Both genetic and environmental factors may be responsible for decreased insulin sensitivity and/or insulin secretion (Sakurai 20000. Medical nutrition therapy is an essential component of successful diabetes management. The three main goals in the dietary management of obese diabetic patients are. To achieve and maintain a reasonable body weight; To keep blood glucose levels in as near-normal range as possible; and To achieve optimal lipid levels. Weight reduction should be considered as a key objective in the management of the obese diabetic patient several anti-obesity drugs have demonstrated a potential interest. However, while fenfluramine and dexfenfluramine have been shown to promote weight loss and to improve insulin sensitivity directly, two mechanisms contributing to a better blood glucose control in obese type 2 diabetic patients, they were recently withdrawn because of safety problems (Scheen 2000). Benfluorex, which is structurally related to fenfluramine, is a known hypolipidaemic agent with possible glucose-lowering effects, especially in the obese diabetic patient, despite the absence of significant effect on body weight (Sakurai 2000). It has been shown to improve glucose tolerance and metabolic control in obese individuals with type 2 diabetes on a body-weight-maintaining diet by increasing sensitivity to insulin without directly stimulating insulin secretion. Two recent double-blind, placebo-controlled trials showed that benfluorex potentiates the effects of a hypocaloric diet on weight loss and on glycaemic control in obese type 2 diabetic patients treated with insulin, presumably by increasing insulin sensitivity (Scheen 2000). Bibliography 1. Holford, P. 2005, The New Optimum Nutrition Bible. Crossing Press; Rev Upd edition. 2. Lipski, E. 2004, Digestive Wellness. McGraw-Hill; 3 edition. 3. Little P, Margetts B, The importance of diet and physical activity in the treatment of conditions managed in general practice, Br J Gen Pract (1996) 46 (404):187-92. 4. Nichols, T. W. Faass, N. 1999, Optimal Digestion : New Strategies for Achieving Digestive Health. Quill Press; 2nd printing edition. 5. Sakurai Y, Duration of obesity and risk of non-insulin-dependent diabetes mellitus, Biomed Pharmacother (2000) 54 :80-4. 6. Scheen AJ, From obesity to diabetes. Why, when and who Acta Clin Belg (2000) 55 : 9-15. Appendix 1. Digestion Read More