Body, human: digestion

The state of knowledge in the early 1990s of the effects of fat on health lacks clarity and general agreement. There is great support for the thesis that fully saturated fats are associated with problems of atherosclerosis and arterial fatty deposit, but there is evidence that stearates, which are saturates, are only poorly utilized in human digestion. Another body of work has estabUshed a connection between unsaturated fatty acids and a better state of arterial health and lowered fat body attachment to the arterial wall (23) contrary evidence exists that highly unsaturated fats polymerize more readily and thus contribute to arterial plaque formation. 

Enzymes are involved in many functions of the human body, including digestion and metabolism. For example, the enzyme lactase is responsible for catalyzing the breakdown of lactose, a sugar found in milk. People who are lactose-intolerant are usually missing lactase, or they have insufficient amounts. If you are lactose-intolerant, you can take commercially produced supplements that contain lactase. 

Carbohydrate metabolism provides glucose, the primary energy source for the human body. After digestion of carbohydrates and absorption of glucose, blood glucose concentration is controlled by the action of several hormones. Glucose can be synthesized de novo or stored in the tissue as glycogen. 

Let me list water s notable properties in a somewhat different order and present a variety of specific examples. Water comes closer to being a universal solvent than any other known substance, a basic property familiar to anyone putting sugar into a cup of coffee. In the human body, the digestive process takes place after nourishment has been dissolved into a liquid - water - solution. Even rocks can be subject to water s dissolving powers witness the ocean s salinity. The solubility of... 

Sucrose esters with a higher degree of substitution, so-called sucrose polyesters (Fig. 8), have characteristic properties of fats and oils. At the same time they are only partly digestible or even nondigestible by the body s lipases and are not absorbed by the human digestive system [7, 22, 42, 43]. Thus, their use as fat replacers appears predetermined and indeed sucrose polyesters with 6-8 acyl moieties were approved by the US Food and Drug Administration (FDA) in 1996 for certain use as fat replacers [43]. Known brand names are Olestra and Olean . They are used in food applications, e.g., in the preparation of dietary fried snacks [2, 42],... 

I have spent at least 8 years, and millions of dollars of research funds, working on ways to deliver insulin, growth hormone, and other peptide drugs into the body without using a syringe. Any pharmaceutical company that could accomplish this feat would capture a multibillion-dollar market. There is a clear financial incentive to produce a peptide pill. However, the conclusions from this research, which are published throughout the world, remain to this day that peptides are destroyed when they enter the hostile environment of the human digestive tract. They just become another protein meal. Their constituent amino acids are absorbed for a nutritional benefit just like any other food source. 

Plants and microorganisms synthesize riboflavin naturally. Some foods rich in riboflavin are brewer s yeast, dark green vegetables, mushrooms, legumes, nuts, milk and other dairy products, sweet potatoes, and pumpkins. Bacteria that live in the human digestive tract are also able to synthesize some riboflavin, but not enough to meet the body s requirement for the vitamin. 

As we have seen in this chapter steroids have a number of functions in human physiology Cholesterol is a component part of cell mem branes and is found in large amounts in the brain Derivatives of cholic acid assist the digestion of fats in the small intestine Cortisone and its derivatives are involved in maintaining the electrolyte balance in body fluids The sex hormones responsible for mascu line and feminine characteristics as well as numerous aspects of pregnancy from conception to birth are steroids... 

Nutritional Value of Milk Products. Milk is considered one of the principal sources of nutrition for humans. Some people are intolerant to one or more components of milk so must avoid the product or consume a treated product. One example is intolerance to lactose in milk. Fluid milk is available in which the lactose has been treated to make it more digestible. The consumption of milk fat, either in fluid milk or in products derived from milk, has decreased markedly in the 1990s. Whole milk sales decreased 12% between 1985 and 1988, whereas the sales of low fat milk increased 165%, and skimmed milk sales increased 48% (35). Nutritionists have recommended that fat consumed provide no more than 30 calories, and that consumption of calories be reduced. Generally, a daily diet of 2000—3000 cal/d is needed depending on many variables, such as gender, type of work, age, body responses, exercise, etc. Further, there is concern about cholesterol [57-88-5] and density of fat consumed. Complete information on the nutritive value of milk and milk products is provided on product labels (36) (see also Table 4). 

Candidate protease inhibitor drugs must be relatively specific for the HIV-1 protease. Many other aspartic proteases exist in the human body and are essential to a variety of body functions, including digestion of food and processing of hormones. An ideal drug thus must strongly inhibit the HIV-1 protease, must be delivered effectively to the lymphocytes where the protease must be blocked, and should not adversely affect the activities of the essential human aspartic proteases. 

The nervous system is a complex part of the human body concerned with die regulation and coordination of body activities such as movement, digestion of food, sleep, and elimination of waste products. The nervous system has two main divisions the central nervous system (CNS) and the peripheral nervous system (PNS). Figure 22-1 illustrates the divisions of die nervous system. 

The hydrolysis of zeaxanthin esters by a carboxyl ester lipase indeed enhanced both the incorporation of zeaxanthin in the micellar phase and uptake of zeaxanthin by Caco-2 cells. As mentioned earher, carotenoids can also be linked to proteins by specific bindings in nature and these carotenoid-protein complexes may slow the digestion process and thus make their assimilation by the human body more difficult than the assimilation of free carotenoids. Anthocyanins are usually found in a glycosylated form that can be acetylated and the linked sugars are mostly glucose, galactose, rhamnose, and arabinose. 

Anthocyanins are poorly absorbed from the gastrointestinal tract and the mechanisms involved remain unclear. These compounds are usually recovered in very small amounts in human serum after oral ingestion (less than 1% of the dose) or in the IN fraction after in vitro digestion (about 5%). ° Unlike other polyphenols, anthocyanins constitute an exception because intact glycosides are recovered in the body (without deglycosylation prior to absorption). - This may be explained by either the instability of the free aglycone form or by a specific mechanism of absorption for anthocyanins. 

Figure 6.1 Acids and bases exist in the human body and are necessary for its proper function, including the function of the digestion process. When food is swallowed, it is attacked by stomach acids. The stomach acids need to be neutralized before food can continue down the digestive tract. A hormone called secretin monitors the pH balance in the small intestine and sends chemical signals to other parts of the body, thereby regulating pH balance.

Pectin, the substance that makes jellies and jams so jelly-like, can help lower blood cholesterol levels by forcing the body to make more bile acids. Pectin is a type of fiber, and like most fiber, pectin cannot be digested by the human body. Instead, the fiber moves slowly through the small intestines. When pectin encounters sugar and acid, its molecules trap water within its long chains, turning into a gel-like mass. This gel traps and eventually eliminates bile acids from the gut. When this happens, the body must make more bile acids, reducing the amount of cholesterol in the blood. 

Symptoms of intoxication in humans caused by accidental ingestion of Kou-Wen plants have been described as follows. The effect on the digestive system starts with loss of appetite and turn of the stomach, and continues to severe abdominal pain and intestinal bleeding. The effect on the respiratory system presents as breathing difficulties which finally lead to death by respiratory failure. The effect on muscle innervation usually results in generalized muscular weakness and paralysis of the limbs. The effect on the circulatory system starts with heartbeat disorders and a drop in blood pressure, but heart failure is not a common cause of death. In addition to dilation of pupils, a drop in body temperature and proliferation of white blood cells have also been obseryed (70). 

---