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By A. Esiel. Siena Heights University.

Longitudinal assessment of the components of energy balance in well-nourished lactating women discount clomiphene 100mg with mastercard menstruation jokes. Longitudinal assessment of energy expenditure in pregnancy by the doubly labeled water method order 100mg clomiphene visa menopause question and answers. Endurance training does not enhance total energy expenditure in healthy elderly persons. Effects of increased energy intake and/or physical activity on energy expendi- ture in young healthy men. Developmental changes in energy expenditure and physical activity in children: Evidence for a decline in physical activity in girls before puberty. Influence of sex, seasonality, ethnicity, and geographic location on the components of total energy expenditure in young children: Implications for energy requirements. Longitudinal changes in fatness in white children: No effect of childhood energy expenditure. No effect of gender on different components of daily energy expenditure in free living prepubertal children. Association between different attributes of physical activity and fat mass in untrained, endurance- and resistance-trained men. Transport of very low density lipoprotein triglycerides in varying degrees of obesity and hypertriglyceridemia. Energy intake, energy expenditure, and body composition of poor rural Philippine women throughout the first 6 mo of lactation. Effects of exercise intensity on cardiovascular fitness, total body composition, and visceral adiposity of obese adolescents. Greater influence of central distribution of adipose tissue on incidence of non-insulin-dependent diabetes in women than men. The relationship of obesity, fat distribution and osteo- arthritis in women in the general population: The Chingford Study. In: Body Composition Mea- surements in Infants and Children: Report of the 98th Ross Conference on Pediatric Research. Basal metabolic rate in human subjects migrating between tropical and temperate regions: A longitudinal study and review of previous work. Are genetic determinants of weight gain modified by leisure-time physical activity? Influence of menstrual cycle on thermoregulatory, metabolic, and heart rate responses to exercise at night. Body-size dependence of resting energy expenditure can be attributed to nonenergetic homogeneity of fat-free mass. The association of body weight, body fatness and body fat distribution with osteoarthritis of the knee: Data from the Baltimore Longitudinal Study of Aging. Long- term follow-up of patients attending a combination very-low calorie diet and behaviour therapy weight loss programme. Metabolic rate and organ size during growth from infancy to maturity and during late gestation and early infancy. Energy expenditure by indirect calorimetry in premenopausal women: Variation within one menstrual cycle. Obesity as an indepen- dent risk factor for cardiovascular disease: A 26-year follow-up of participants in the Framingham Heart Study. Effect of ten weeks of vigorous daily exercise on serum lipids and lipoproteins in teenage males. Racial differences in energy expenditure and aerobic fitness in premenopausal women. Metabolically active components of fat free mass and resting energy expenditure in non- obese adults. Determining energy expenditure in preterm infants: Comparison of 2H 18O method and indirect calorimetry. Energy expenditure of Chinese infants in Guangdong Province, south China, determined with use of the doubly labeled water method. Correlates of over- and under- reporting of energy intake in healthy older men and women. Literacy and body fatness are associated with underreporting of energy intake in U. Canadian Recommended Nutrient Intakes underestimate true energy requirements in middle-aged women. Carbohydrate and lipid metabolism during normal pregnancy: Relationship to gestational hormone action. Differences in resting energy expendi- ture in prepubertal black children and white children. Determinations of standard energy metabolism (basal metabo- lism) in normal infants. Influence of upper and lower thermo- neutral room temperatures (20°C and 25°C) on fasting and post-prandial resting metabolism under different outdoor temperatures. Prospective study of clini- cal gallbladder disease and its association with obesity, physical activity, and other factors. Energy balance during an 8-wk energy-restricted diet with and without exercise in obese women. No relationship between identified variants in the uncoupling protein 2 gene and energy expenditure. Calorimetric validation of the doubly-labelled water method for determination of energy expenditure in man. Metabolic and thyroidal responses to mild cold are abnormal in obese diabetic women. Body fat and water changes during pregnancy in women with different body weight and weight gain. Underestimation of daily energy expenditure with the factorial method: Implications for anthropological research. Hematological parameters in high altitude residents living at 4,355, 4,660, and 5,500 meters above sea level. Discrepancy between self-reported and actual caloric intake and exercise in obese subjects. Theory of use of the turnover rates of body water for measuring energy and material balance. The fate of utilized molecular oxygen and the source of the oxygen of respiratory carbon dioxide, studied with the aid of heavy oxygen. The effect of physical conditioning on serum lipids and lipoproteins in white male adolescents. Longitudinal changes in the relationship between body mass index and percent body fat in pregnancy.

Outbreaks have been reported in some domestic animals (mainly pigs) after consuming feeds containing meat and bone meal originating from carcases contaminated with anthrax bacterial spores cheap clomiphene 50 mg fast delivery sa health women's health. Wild carnivores and scavengers become infected through the consumption of infected meat buy clomiphene 25mg otc menopause relief. After feeding on an infected carcase, non-biting blowflies may contaminate vegetation by depositing vomit droplets and subsequently animals feeding on such vegetation then become infected. Although a minor mode of transmission, biting flies may transmit the disease from one animal to another during severe outbreaks. How is the disease Humans can become infected with anthrax by breathing in anthrax spores transmitted to humans? Consumption of undercooked meat from infected animals may cause gastrointestinal anthrax. Acute cases in cattle, sheep and wild herbivores are characterised by fever, depression, difficulty in breathing and convulsions, and, if untreated, animals may die within two or three days. In pigs, anthrax is characterised by swelling of the throat, causing difficulties in breathing and similar characteristics are seen in dogs, cats and wild carnivores. The incubation period of anthrax is typically 3 to 7 days (ranging from 1 to 14 days). Apoplectic – occurs most frequently at the beginning of an outbreak, where animals (mostly cattle, sheep, goats and wild herbivores) show signs of loss of conciousness and sudden death. Signs include fever, ruminal stasis, excitement followed by depression, difficulty in breathing, uncoordinated movements, convulsions and death. Unclotted blood issuing from body orifices, rapid decomposition of the carcase and incomplete rigor mortis are often observed. Chronic anthrax – can be seen in cattle, horses and dogs but occurs mainly in less susceptible species such as pigs and wild carnivores. Characterised by swelling of the throat and tongue and a foamy discharge from the mouth. Recommended action if Contact and seek assistance from appropriate animal health professionals. Diagnosis In animals, anthrax is diagnosed using samples taken from superficial blood vessels or natural openings of dead animals and by examining blood smears on a microscope slide. Artificial media can be used to grow the micro- organism from a dead animal, hides, skin, wool or soil. Livestock In areas prone to anthrax a preventive strategy should be adopted involving thorough surveillance and annual vaccination of susceptible animals (usually cattle, sheep and goats). Vaccination is normally carried out 2-4 weeks before the onset of the known period of outbreaks. Any animals showing signs of anthrax must be treated and not used for food until several months after the completion of treatment. The live Sterne vaccine is effective but there is some concern over its ecological effect and possible pathogenicity in some species. Antibiotic treatment (penicillin or tetracycline) can be an option if animals show clinical signs of anthrax but often it is not a practical or feasible method of control. Culling of infected animals and removal of diseased carcases reduces contamination sources. When this is not possible, place the unopened carcases in heavy duty black plastic bags which are sealed and leave in the heat. Carcases infected with anthrax should not be moved, instead they should be disposed of using appropriate methods on site to prevent further environmental contamination. Above all, be alert, vigilant and maintain surveillance particularly during high risk times. Anthrax is a seasonal disease which may reoccur the following year and being prepared for potential outbreaks is vital. This includes early carcase detection along with minimising environmental contamination through proper carcase disposal and decontamination Wildlife species should be monitored for any interaction with livestock (e. Burning surrounding areas of bush to kill spores and disperse unaffected wildlife. Trained personnel and advisory information are required to effectively manage the control of an outbreak and attempts should be made to identify the source and mode of transmission in order to inform the response team. Prevention of anthrax in wildlife depends on recognising risk factors such as seasonality, density of susceptible hosts, rainfall patterns, history, soil type and so on (Sally MacKenzie). Wash hands with soap and water to remove the vast majority of spores and keep fingers away from the mouth and nose. Treat wounds or scratches as soon as possible to reduce cutaneous infection by spore contamination. In the presence of acute respiratory infections or other debilitation, be on alert for "flu-like" symptoms as pulmonary infections are most likely. In the unlikely event of contracting anthrax, treatment is highly effective with simple penicillin, erythromycin G, tetracycline and a variety of other antibiotics. The impacts can be greater where protected areas are smaller and where losses are proportionally greater. Outbreaks can put endangered species at risk of mass die-offs and rapid population decline. A number of significant, high mortality anthrax epidemics in wildlife have occurred in Africa over the last decades. These have included: thousands of hippopotamuses on the Zambesi; in Queen Elizabeth National Park, Uganda; and affecting a variety of species in Zimbabwe, Ethiopia, Tanzania; and endangered Grevy’s zebra Equus grevyi in Kenya. Some protected areas and other environments have recurrent infection where the epidemiology is now well understood, e. Some of these outbreaks are a result of spillover of infection from livestock epidemics especially where there is a breakdown in livestock vaccination. Other disease control measures such as foot and mouth disease fences have had an impact on the incidence of anthrax, keeping population densities high in some susceptible regions allowing the disease to become endemic and causing regular outbreaks. Effect on livestock Livestock anthrax is declining in many regions of the world due to good prevention and control measures. That said, the disease can still cause heavy losses and will remain a particular problem where the disease is present in wildlife areas and there is contact between wild and domestic populations. Effect on humans A potentially fatal zoonotic infection and thus a risk to human health when dealing with infected animals or their products. Livestock losses impact food security and livelihoods particularly in regions where disease is endemic. Economic importance Economic losses may be significant as a result of anthrax outbreaks especially for livestock traders. Revue Scientifique et Technique de l’Office International des Épizooties, 21 (2): 359-383. A paralytic and often fatal disease of birds caused by ingestion of a toxin produced by the bacterium Clostridium botulinum. Bacterial spores are widely distributed in wetland sediments and can be found in the tissues of most wetland inhabitants, including aquatic insects, molluscs and crustacea and many vertebrates, including healthy birds. Spores may survive for years but only give rise to the bacteria that produce the toxins under certain environmental conditions.

In acute cholecystitis 90% of patients settle with conser- vative management within 4–5 days order clomiphene 100mg on line breast cancer lanyard. Ascending cholan- Carcinoma of the bile ducts gitishasamortalityofupto20%inseverecasesrequiring emergency decompression generic clomiphene 25mg amex menstrual yeast infections. Carcinoma of the gallbladder is rare, but almost always associated with gallstones. The tumour can arise anywhere in the biliary sys- Aetiology/pathophysiology tem and may be multifocal. It causes obstruction and Unknown, but associated with gallstones and chronic hence dilatation of the proximal ducts. Histologically 90% of tumours are adeno- carcinomas and 10% are squamous carcinomas. Clinical features The usual presentation is progressive obstructive jaun- Clinical features dice. Other symptoms include vague epigastric or right Patients may have a history of gallstone disease. A mass is often palpable in the right upper empyema presenting with biliary colic and a non-tender quadrant. Direct invasion of local structures, especially the liver, is almost invari- Macroscopy/microscopy ableatpresentation. Spreadviathelymphaticsandblood The carcinoma commonly appears as a sclerotic stricture occurs early. The islets of Langerhans are islands of endocrine cells scattered throughout the pancreas. They are clustered Investigations around a capillary network into which they secrete their r Ultrasound may show dilated intrahepatic ducts and hormones. Management Acute pancreatitis Curative treatment is only attempted if the tumour is localised and the patient is fit for radical resection. Definition r Carcinoma of the common bile duct is treated by the Acute inflammation of the pancreas with variable in- Whipple’s operation (see page 221). Incidence The remaining biliary tree is anastomosed to a Roux Almost 5–25 per 100,000 per year and rising. Palliative treatments include insertion of a stent or anas- Age tomosis of a Roux loop of jejunum to a biliary duct in More common >40 years. The prognosis is better for patients with carcinoma of Aetiology the common bile duct who are suitable for a Whipple’s Biliary tract disease (80%), especially cholelithiasis, gall- operation. Alcoholism is the second most common cause (20% in the United Disorders of the pancreas Kingdom). Causes are as follows: r Obstruction: Gallstones, biliary sludge, carcinoma of the pancreas. Introduction to the pancreas r Drugs/toxins: Alcohol, azathioprine, steroids, diuret- The pancreas has two important functions: the produc- ics. Proteolysis Chapter 5: Disorders of the pancreas 219 due to proteases, fat necrosis due to lipases and phos- Table5. Translocation of gut pancreatitis bacteria can result in local infection and septicaemia. Within 48 hours of admission Shock may result from the release of bradykinin and Age >55 years prostaglandins, or secondary to sepsis. Haemorrhage may cause Grey– Turner’s sign, which is bruising around the left loin and/or Cullen’s sign, bruising around the umbilicus. The pancreas appears oedematous with grey-white Other investigations are required to assess the sever- necrotic patches. Bacterial infection leads to inflamma- ity and to monitor for complications: full blood count, tion and pus formation. Healing results in fibrosis with clotting screen, urea and electrolytes, liver function tests, calcification. Complications In the most severe cases there is systemic organ failure: Management r Cardiovascularsystem:Shock(hypotension,tachycar- The early management depends on the severity of the dia, arrhythmias). Patients require careful fluid balance zymes walled off by compressed tissue), pancreatic using central venous pressure monitoring and uri- abscesses (which may contain gas indicating infection nary catheterisation to allow accurate urine output withgas-formingbacteria)andduodenalobstruction. Prophylactic Investigations broad-spectrumantibioticsaregiventoreducetherisk When supportive clinical features are present the diag- of infective complications. Ascites and persistent obstructive jaundice with conservative management require laparoscopic may occur. Prognosis Investigations Pancreatitis is a serious condition: overall mortality is Serum amylase fluctuates, but may be moderately raised 10%. Endoscopic retrograde cholangiopancreatography mayshowscarringoftheductalsystemandevenstonesin the pancreatic duct. Magnetic resonance cholangiopan- Chronic pancreatitis creatography is increasingly being used. Definition Chronic pancreatitis is an inflammatory condition that Management results in irreversible morphological change and impair- Precipitating factors especially alcohol need to be re- ment of exocrine and endocrine function. Adequate analgesia is required, thoracoscopic splanchnicectomymayberequiredinrefractorypainnot Age associated with main pancreatic duct dilatation. Surgical M > F techniques include sphincteromy or sphincteroplasty, partial pancreatectomy or opening the pancreatic duct Aetiology/pathophysiology along its length and anastomosing it with the duodenum Two patterns of chronic pancreatitis are seen, a chronic or jejunum. Total pancreatectomy can be carried out, relapsing course with recurring acute pancreatitis and with replacement oral pancreatic enzymes and insulin. Risk factors includealcoholabuse,hereditarypancreatitis,ductalob- Tumours of the pancreas struction (e. Hy- percalcaemia, hyperlipidaemia and congenital pancre- Definition atic malformations are recognised associations. Clinical features Incidence Patients may present with an acute episode of pancre- 10 per 100,000 per annum and rising. Late com- plications include impaired glucose tolerance, diabetes Age mellitus and malabsorption (steatorrhoea) associated Mainly >60 years. Chapter 5: Disorders of the pancreas 221 Sex Complications 2M : 1F The main routes of spread are local causing obstruc- tive jaundice or invasion of the duodenum, lymphatic to Geography adjacent lymph nodes which drain into the coeliac and In many Western countries it is the fourth commonest superior mesenteric lymph nodes and haematogenous cause of cancer death in males and in females, the sixth. Aetiology There appears to be some familial clustering and hence Investigations it is suggested that genetic susceptibility may play an There are no useful tumour markers or pancreatic func- important role. Specific inherited risks include famil- tion tests for diagnosis, which must be histological. Mosttumoursdevelop intheheadofthepancreasandthesetendtopresentearly ducts and may also be used for intervention. Clinical features Pancreatic cancer is associated with several clinical syn- Management dromes: Surgical resection offers the only chance of cure, but only r One third of patients present with painless obstructive about 10–15% of patients are suitable for radical surgery jaundice, i. Chronic epigastric pain radiating to the back similar to chronic pancre- denectomy with block resection of the head of pan- atitis develops in most patients at some stage. There is significant orrhoea is common and failure to absorb the fat- perioperative morbidity and mortality. Stents of the bile duct and/or duodenum tend to become blocked and Macroscopy/microscopy have to be replaced.

Evolutionary biologists and physicians have been concerned with different problems buy clomiphene visa women's health center dickson tn, they speak different specialized languages purchase clomiphene 100mg overnight delivery pregnancy fashion, and they see the natural world in different ways. These differences have helped to keep these fields apart and continue to hinder their integration. The Theory of Evolution by Natural Selection Although our understanding of evolution has increased greatly since Darwin’s time, biologists still use essentially the same arguments to support the theory of evolution by natural selection as Darwin did when he proposed it. Darwin began by pointing out the abundant variation that exists among indi- vidual organisms in a population. The first two chapters of On the Origin of Species (1859) are devoted to a discussion of variation, first in domesticated species and then in nature. Darwin focused on small, often barely discernible, variations; he regarded the greatly deviant organisms that occasionally arise in nature as “monstrosities” that had no role in evolution. Of course, people had long been aware of variations among organisms within populations or species. As Ernst Mayr (1964) has emphasized, however, before Darwin species were understood in typological or essentialist terms. In this view, each species was thought to be characterized by a unique, unchanging essence. Variation was seen as an irrelevant distraction, due to imperfections in the material realization of the ideal form of the species. Biologists no longer think of species as having ideal or essential forms: instead, they commonly think about species (at least extant, sex- ually reproducing species) in terms of Mayr’s biological species concept. Ac- cording to this concept, species comprise populations of organisms that can interbreed and produce viable offspring in nature but that otherwise exhibit a wealth of variation and change over time—in other words, species evolve (Mayr 1988a). Variation remains a critical aspect of evolutionary thinking because it provides the raw material for evolution by natural selection. Next, Darwin pointed out that, while the number of organisms in a popula- tion might potentially increase without limit, the resources needed to support these populations are finite. In other words, the reproductive capacity of the organisms in a population must greatly exceed what we now call the carrying capacity of the environment, the population that the local habitat can sustain. This inequality between reproductive potential and environmental resources means that individual organisms in a population must compete for survival and reproduction. Darwin called this competition the “struggle for existence,” a con- cept based on Thomas Malthus’s Essay on the Principle of Population (1798); in The Origin, he refers to the struggle for existence as “the doctrine of Malthus applied with manifold force to the whole animal and vegetable kingdoms” (Darwin 1859, p. Malthus was concerned with the disparity between human popu- lation growth and the availability of food. Darwin expanded Malthus’s ideas from spring 2013 • volume 56, number 2 171 Robert L. Perlman humans to all species and from food to all of the environmental resources that organisms need to survive and reproduce. Evolutionists understand the struggle for existence in what Darwin called “a large and metaphorical sense” (p. Organisms struggle to secure food and other resources they need to grow and develop, to avoid being eaten by predators, to attract mating partners and repro- duce, and to promote the survival of their offspring. Although the term may conjure visions of hand-to-hand combat, the struggle for existence is primarily a struggle between organisms and their environments. Only occasionally does the struggle for existence involve a direct physical confrontation between two individuals of the same species, as in two dogs fighting over a scarce piece of meat or two males fighting to mate with a female. The environment in which the struggle for existence takes place includes both the physical or nonliving environment (air, water, sunlight, climate, etc. The biotic environment comprises all of the other species with which organisms interact or on which they depend (di- rectly or indirectly), as well as other members of their own species. Organisms of other species constitute especially important components of an organism’s environment. For this reason, evolution is closely connected to ecology and to the ecological relationships among species. Many of us in developed countries live in environments in which our interactions with organisms of other species are largely hidden. Our direct experience is limited to our pets, to the plants and animals in our gardens and parks, to the insects and other pests that annoy or plague us, to infectious microorganisms, and to the food we eat, much of which we purchase prepackaged in grocery stores. We should remember, however, that our lives and our health are intimately related to and affected by the innumer- able species that form part of our environment—those that contribute to our health, as well as those that cause disease. Those individuals that are successful in the struggle for existence will survive, reproduce, and leave offspring; in evolutionary terms, producing offspring who themselves survive and reproduce is the definition of success. Biologists com- monly use the term fitness, sometimes modified as reproductive or evolutionary fit- ness to avoid confusion, to denote this reproductive success. The term “survival of the fittest,” introduced by the English philosopher Herbert Spencer (1864), has become a widely used metaphor to describe the evolutionary process. This metaphor may be misleading, however, because it is easy for people who are concerned with “fitness” today to think that evolutionary fitness refers to some- thing akin to physical fitness. In evolutionary terms, fitness does not simply refer to strength or endurance, but to all of the traits that enable organisms to func- tion—to survive and produce offspring—in their environments. They fit into and may shape their environments the way hands fit into and shape gloves. Although we often talk loosely about the fitness of organisms, fitness is best understood in terms of alleles or genotypes. In this respect, fitness is the expected average reproductive success of organisms of a given genotype, relative to the average reproductive success of other organisms in the population. Alleles that enhance fitness survive in the sense that they are preferentially transmitted from parents to offspring. Thus, in genetic terms, fitness may be thought of as the ability of organisms of a specific genotype to contribute genes to the gene pools of their populations. Organisms can pass on their genes directly, by their own reproduction, or indirectly, by en- hancing the reproductive success of their genetic relatives. A broader concept of fitness, which is especially relevant to social species such as humans, is inclusive fitness, which comprises both the direct and indirect components of fitness (Hamilton 1964). Although Darwin did not understand the molecular basis of heredity, he rec- ognized that many traits are heritable. As a result, traits that increase survival and reproduction—traits that make organisms well suited to their environments and thus enable them to suc- ceed in the struggle for existence—will in general spread in the population. In contrast, traits that decrease survival and reproduction, and the alleles that under- lie these traits, will, over time, be eliminated. This is natural selection, which Dar- win defined as “This preservation of favourable variations and the rejection of injurious variations” (Darwin 1859, p. Favorable variations—traits associated with increased fitness—that are preserved by natural selection are known as adaptations. Darwin adopted the term natural selection by analogy with artificial selection, which he called “selection by man.

Studies report no differences in magnesium balance with intake of certain Dietary Fibers (Behall et al order 100mg clomiphene mastercard pregnancy outfits. Astrup and coworkers (1990) showed no effect of the addition of 30 g/d of plant fiber to a very low energy diet on plasma concentrations of magnesium order genuine clomiphene on line women's health clinic va. There was no effect on the apparent absorption of magnesium after the provision of 15 g/d of citrus pectin (Sandberg et al. Magnesium balance was not significantly altered with the consumption of 16 g/d of cellulose (Slavin and Marlett, 1980). A number of studies have looked at the impact of fiber- containing foods, such as cereal fibers, on iron and zinc absorption. These cereals typically contain levels of phytate that are known to impair iron and zinc absorption. Coudray and colleagues (1997) showed no effect of isolated viscous inulin or partly viscous sugar beet fibers on either iron or zinc absorption when compared to a control diet. Metabolic balance studies conducted in adult males who consumed four oat bran muffins daily showed no changes in zinc balance due to the supplementation (Spencer et al. Brune and coworkers (1992) have suggested that the inhibi- tory effect of bran on iron absorption is due to its phytate content rather than its Dietary Fiber content. There are limited studies to suggest that chronic high intakes of Dietary Fibers can cause gastrointestinal distress. The con- sumption of wheat bran at levels up to 40 g/d did not result in significant increases in gastrointestinal distress compared to a placebo (McRorie et al. For instance, 75 to 80 g/d of Dietary Fiber has been associated with sensations of excessive abdominal fullness and increased flatulence in individuals with pancreatic disease (Dutta and Hlasko, 1985). Furthermore, the consumption of 160 to 200 g/d of unprocessed bran resulted in intestinal obstruction in a woman who was taking an antidepressant (Kang and Doe, 1979). Summary Dietary Fiber can have variable compositions and therefore it is difficult to link a specific fiber with a particular adverse effect, especially when phytate is also often present. It is concluded that as part of an overall healthy diet, a high intake of Dietary Fiber will not produce significant deleterious effects in healthy people. Special Considerations Dietary Fiber is a cause of gastrointestinal distress in people with irritable bowel syndrome. Those who suffer from excess gas production can consume a low gas-producing diet, which is low in dietary fiber (Cummings, 2000). Hazard Identification for Isolated and Synthetic Fibers Unlike Dietary Fiber, it may be possible to concentrate large amounts of Functional Fiber in foods, beverages, and supplements. Since the potential adverse health effects of Functional Fiber are not completely known, they should be evaluated on a case-by-case basis. In addition, projections regard- ing the potential contribution of Functional Fiber to daily Total Fiber intake at anticipated patterns of food consumption would be informative. Func- tional Fiber, like Dietary Fiber, is not digested by mammalian enzymes and passes into the colon. Thus, like Dietary Fiber, most potentially deleterious effects of Functional Fiber ingestion will be on the interaction with other nutrients in the gastrointestinal tract. Data from human studies on adverse effects of consuming what may be considered as Functional Fibers (if suffi- cient data exist to show a potential health benefit) are summarized below under the particular fiber. Chitin and Chitosan Studies on the adverse effects of chitin and chitosan are limited. While the adverse gastrointestinal effects of gums are limited, incidences of moderate to severe degrees of flatulence were reported from a trial in which 4 to 12 g/d of a hydrolyzed guar gum were provided to 16 elderly patients (Patrick et al. Gums such as the exudate gums, gum arabic, and gum tragacanth have been shown to elicit an immune response in mice (Strobel et al. When F-344 rats, known to have a high incidence of neoplastic lesions, were given 0, 8,000, 20,000, or 50,000 ppm doses of fructooligo- saccharide, the incidence of pituitary adenomas was 20, 26, 38, and 44 per- cent, respectively (Haseman et al. Clevenger and coworkers (1988) reported no difference in the onset of cancer in F-344 rats fed 0, 8,000 (341 to 419 mg/kg/d), 20,000 (854 to 1,045 mg/kg/d), or 50,000 ppm (2,170 to 2,664 mg/kg/d) doses of fructooligosaccharide compared with the controls. Henquin (1988) observed a lack of developmental toxicity when female rats were fed a diet containing 20 per- cent fructooligosaccharide during gestation. When pregnant rats were fed diets containing 5, 10, or 20 percent fructooligosaccharide during ges- tation, no adverse developmental effects were observed (Sleet and Brightwell, 1990). Fructooligosaccharide has been tested for genotoxicity using a wide range of test doses (0 to 50,000 ppm); the results indicated no genotoxic potential from use of fructooligosaccharide (Clevenger et al. Cramping, bloating, flatulence, and diarrhea was observed at intakes ranging from 14 to 18 g/d of inulin (Davidson and Maki, 1999; Pedersen et al. Consumption of 5 or 15 g/d of fructooligosaccharide produced a gaseous response in healthy men (Alles et al. Briet and coworkers (1995) reported increased flatulence as a result of consuming more than 30 g/d of fructo- oligosaccharide, increased bloating at greater than 40 g/d, and cramps and diarrhea at 50 g/d. Increased flatulence and bloating were observed when 10 g/d of fructooligosaccharide was consumed (Stone-Dorshow and Levitt, 1987). The role carbohydrate malabsorption plays in the onset of diarrhea most likely depends upon the balance between the osmotic force of the carbohydrate and the capacity of the colon to remove the carbohydrate via bacterial fermentation. In order to evaluate the significance of osmolarity, Clausen and coworkers (1998) compared the severity of diarrhea after consumption of fructooligosaccharide and lactulose, both of which are nonabsorbable carbohydrates. Although both carbohydrates are fermented by colonic microflora, they differ in osmolarity. In a crossover design, 12 individuals were given fructooligosaccharide or lactulose in increasing doses of 0, 20, 40, 80, and 160 g/d. The increase in fecal volume measured as a function of the dose administered was twice as high for lactulose as for fructooligosaccharide; however, there was substantial interindividual varia- tion in the response. The researchers concluded that fecal volume in carbohydrate-induced diarrhea is proportional to the osmotic force of the malabsorbed saccharide, even though most is degraded by colonic bacteria (Clausen et al. Anaphylaxis was observed following the intravenous administration of inulin for determining the glomerular filtration rate (Chandra and Barron, 2002). A skin-pricking test revealed hypersensitivity to each of the above foods or ingredients (Gay-Crosier et al. Pectin Pectin has been shown to have a negligible effect on zinc retention in humans (Lei et al. Polydextrose Polydextrose has showed no reproductive toxicity, teratology, muta- genicity, genotoxicity, or carcinogenesis in experimental animals (Burdock and Flamm, 1999). In humans, no reports of abdominal cramping or diarrhea were reported in men and women who were given up to 12 g/d of polydextrose (Jie et al. Furthermore, there were no complaints of abdominal distress with the consumption of 30 g/d of polydextrose (Achour et al. However, flatulence and gas-related problems were reported following the intake of 30 g/d of polydextrose (Tomlin and Read, 1988). Diarrhea was reported with the consumption of 15 g/d of poly- dextrose; however, this symptom ceased after 1 month of intake (Saku et al. In a meta-analysis of eight studies regarding psyllium intake, the authors found that psyllium was well tolerated and safe (Anderson et al. Esophageal obstruction was noted in an elderly man who regularly took a “heaping” teaspoon with some water (Noble and Grannis, 1984). Furthermore, an elderly woman who was given 2 tbs of a psyllium-based laxative three times daily suffered from small- bowel obstruction (Berman and Schultz, 1980).

These recommen- dations should be helpful in evaluating diet and disease relationship studies as it will be possible to classify fiber-like components as Functional Fibers due to their documented health benefits discount clomiphene generic breast cancer types. Although databases are not cur- rently constructed to delineate potential beneficial effects of specific fibers generic clomiphene 100 mg visa women's health center in salisbury md, there is no reason that this could not be accomplished in the future. Potential Functional Fibers for food labeling include isolated, nondigestible plant (e. How the Definitions Affect the Interpretation of This Report The reason that a definition of fiber is so important is that what is or is not considered to be dietary fiber in, for example, a major epidemiological study on fiber and heart disease or fiber and colon cancer, could deter- mine the results and interpretation of that study. However, that should not detract from the relevance of the recommendations, as the database used to mea- sure fiber for these studies will be noted. Such a database represents Dietary Fiber, since Functional Fibers that serve as food ingredients contribute a minor amount to the Total Fiber content of foods. Other epidemiological studies have assessed intake of specific high fiber foods, such as legumes, breakfast cereals, fruits, and vegetables (Hill, 1997; Thun et al. Intervention studies often use specific fiber supplements such as pectin, psyllium, and guar gum, which would, by the above definition, be considered Functional Fibers if their role in human health is documented. For the above reasons, the type of fiber (Dietary, Functional, or Total Fiber) used in the studies discussed later in this chapter is identified. Description of the Common Dietary and Functional Fibers Below is a description of the Dietary Fibers that are most abundant in foods and the Functional Fibers that are commonly added to foods or pro- vided as supplements. To be classified as a Functional Fiber for food labeling purposes, a certain level of information on the beneficial physiological effects in humans will be needed. For some of the known beneficial effects of Dietary and potential Functional Fibers, see “Physiological Effects of Iso- lated and Synthetic Fibers” and “Evidence Considered for Estimating the Requirement for Dietary Fiber and Functional Fiber. Cellulose, a polysaccharide consisting of linear β-(1,4)−linked glucopyranoside units, is the main structural component of plant cell walls. Powdered cellulose is a purified, mechani- cally disintegrated cellulose obtained as a pulp from wood or cotton and is added to food as an anticaking, thickening, and texturizing agent. Dietary cellulose can be classified as Dietary Fiber or Functional Fiber, depending on whether it is naturally occurring in food (Dietary Fiber) or added to foods (Functional Fiber). Chitin is an amino-polysaccharide containing β-(1,4) linkages as is present in cellulose. Chitin and chitosan are primarily consumed as a supplement and poten- tially can be classified as Functional Fibers if sufficient data on physiological benefits in humans are documented. These β-linked D-glucopyranose polymers are constituents of fungi, algae, and higher plants (e. Naturally occurring β-glucans can be classified as Dietary Fibers, whereas added or isolated β-glucans are potential Functional Fibers. Gums consist of a diverse group of polysaccharides usually iso- lated from seeds and have a viscous feature. Galactomannans are highly viscous and are therefore used as food ingredients for their thickening, gelling, and stabi- lizing properties. Hemicelluloses are a group of polysaccharides found in plant cell walls that surround cellulose. These polymers can be linear or branched and consist of glucose, arabinose, mannose, xylose, and galact- uronic acid. Most of the commercially available inulin and oligofructose is either synthesized from sucrose or extracted and purified from chicory roots. Inulin is a polydisperse β-(2,1)-linked fructan with a glucose molecule at the end of each fructose chain. Synthetic oligofructose contains β-(2,1) fructose chains with and without terminal glucose units. Synthetic fructooligosaccharides have the same chemical and structural composition as oligofructose, except that the degree of polymerization ranges from two to four. Because many current definitions of dietary fiber are based on methods involving ethanol precipitation, oligosaccharides and fructans that are endogenous in foods, but soluble in ethanol, are not analyzed as dietary fiber. With respect to the definitions outlined in this chapter, the naturally occurring fructans that are found in plants, such as chicory, onions, and Jerusalem artichoke, would be classified as Dietary Fibers; the synthesized or extracted fructans could be classified as Func- tional Fibers when there are sufficient data to show positive physiological effects in humans. Lignin is a highly branched polymer comprised of phenyl- propanoid units and is found within “woody” plant cell walls, covalently bound to fibrous polysaccharides (Dietary Fibers). Although not a carbo- hydrate, because of its association with Dietary Fiber, and because it affects the physiological effects of Dietary Fiber, lignin is classified as a Dietary Fiber if it is relatively intact in the plant. Lignin isolated and added to foods could be classified as Functional Fiber given sufficient data on positive physi- ological effects in humans. Pectins, which are found in the cell wall and intracellular tissues of many fruits and berries, consist of galacturonic acid units with rhamnose interspersed in a linear chain. Pectins frequently have side chains of neutral sugars, and the galactose units may be esterified with a methyl group, a feature that allows for its viscosity. While fruits and veg- etables contain 5 to 10 percent naturally occurring pectin, pectins are industrially extracted from citrus peels and apple pomace. Isolated, high methoxylated pectins are mainly added to jams due to their gelling prop- erties with high amounts of sugar. Low methoxylated pectins are added to low-calorie gelled products, such as sugar-free jams and yogurts. Polydextrose is a polysaccharide that is synthesized by random polymerization of glucose and sorbitol. Polydextrose serves as a bulking agent in foods and sometimes as a sugar substitute. Polydextrose is not digested or absorbed in the small intestine and is partially fermented in the large intestine, with the remaining excreted in the feces. Psyllium refers to the husk of psyllium seeds and is a very viscous mucilage in aqueous solution. The psyllium seed, also known as plantago or flea seed, is small, dark, reddish-brown, odorless, and nearly tasteless. Indigestible components of starch hydrolysates, as a result of heat and enzymatic treatment, yield indigestible dextrins that are also called resistant maltodextrins. Unlike gums, which have a high viscosity that can lead to problems in food processing and unpleasant organoleptic properties, resistant maltodextrins are easily added to foods and have a good mouth feel. Resistant maltodextrins are produced by heat/acid treat- ment of cornstarch, followed by enzymatic (amylase) treatment. The average molecular weight of resistant maltodextrins is 2,000 daltons and consists of polymers of glucose containing α-(1-4) and α-(1-6) glucosidic bonds, as well as 1-2 and 1-3 linkages. Resistant dextrins can potentially be classified as Functional Fibers when sufficient data on physiological benefits in humans are documented. Resistant starch is naturally occurring, but can also be produced by the modification of starch during the processing of foods. Resistant starch is estimated to be approximately 10 percent (2 to 20 percent) of the amount of starch consumed in the Western diet (Stephen et al. Along the gastrointestinal tract, properties of fiber result in differ- ent physiological effects. Effect on Gastric Emptying and Satiety Consumption of viscous fibers delays gastric emptying (Low, 1990; Roberfroid, 1993) and expands the effective unstirred layer, thus slowing the process of absorption once in the small intestine (Blackburn et al.

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