Mutagens in feces have been suggested to be an indicator for risk of colon cancer. Groups consuming vegetarian diets are known to have lower mortality from colon cancer. The purpose of this study was to assess mutagenic activity in feces of persons habitually consuming vegetarian or non-vegetarian diets and to try to identify dietary factors or other health habits which contributed to fecal mutagenicity. Eleven strict vegetarians, six ovo-lacto vegetarians and twelve non-vegetarians, all from the Greater Vancouver area, participated in this study. Data on certain demographic variables and health habits, as well as dietary intake (food frequency and food records), were taken. One fecal sample was collected from each subject for the study. Aqueous extracts of the feces were prepared and analyzed for mutagens using the fluctuation test with Salmonella typhimurium TA100 and TA98. Levels of mutagenicity on each organism were then statistically correlated with frequency of consumption of food groups, nutrient intake, demographic data and health habits. Ovo-lacto vegetarians and strict vegetarians, as groups, had significantly lower levels of fecal mutagens than non-vegetarians in the TA100 assay. With TA98, only the strict vegetarians had lower levels of mutagens compared to the non-vegetarians. The presence of several different mutagenic compounds was indicated. Significant negative correlations were found with mutagenicity on TA98 for all subjects with the following dietary variables: fruits and juices, fiber and iron. Similar negative correlations were found for total carbohydrate and Southgate fiber intakes and mutagenicity on TA100. Within the group of non-vegetarians, there were negative correlations with mutagenicity on TA98 and total protein and with mutagenicity on TA100 and calcium. With the demographic variables and health habits, no clear pattern emerged to indicate factors which would predict lowered mutagenicity for all subjects. It is concluded that vegetarians have lower levels of fecal mutagenicity and that several dietary factors are likely to contribute to this phenomenon. / Land and Food Systems, Faculty of / Graduate

Macrophage-derived foam cells play a predominant role in the deposition of arterial plaques during the early stages of atherosclerosis. The deposition of arterial plaques is known to be effected by several factors, including a person’s dietary habits. The consumption of a high-fat (>60% of calories from fat) meal is known to elevate serum LDL and triglycerides, which have been previously implicated in the formation pf foam cells. One limitation of current research models is that it is not possible to directly measure foam cells in vivo. Thus, the purpose of the present study was to validate the use of blood derived monocytes as a proxy measure of foam cells. In order to complete this objective, we evaluated monocyte oxLDL phagocytosis capacity following consumption of a high-fat meal. Eight men and women participated in the present study and venous blood samples were collected prior to the meal, 1-h, 3-h, and 5-h post-meal. Monocytes (CD14+/16- and CD14+/16+) were evaluated for adhesion molecule expression (CD11a, CD11b, and CD18), scavenger R (CD36) expression, and oxLDL phagocytosis using an image-based flow cytometry method developed in our laboratory for this purpose. Data was statistically analyzed for significance using a single-factor ANOVA with repeated measures and a p < 0.05. Consumption of a high-fat meal caused an increase significant increase in the proportion of pro-inflammatory monocytes (CD14+/16+) and a decrease in classic monocytes (CD14+/16-), with the greatest difference occurring at 5 h post prandial (p = 0.038). We also found that pro-inflammatory monocyte expression of adhesion molecules and CD36 increased in a manner that would promote in vivo movement of monocytes into the subendothelial space. Finally, over the course of the 5 h postprandial period, the majority of oxLDL uptake occurred in pro-inflammatory compared to classic monocytes. These results suggest that consuming a high-fat meal increases the potential of monocytes to become foam cells for at least 5 h postprandial.

Health coaching is a promising approach to support self-management of chronic conditions like type 2 diabetes; however, there aren’t enough coaching practitioners to support those in need. Advances in Artificial Intelligence (AI) and Machine Learning (ML) have the potential to enable innovative, automated health coaching interventions, but important gaps remain in applying AI and ML to coaching interventions. This thesis aims to identify computational approaches and interactive technologies that enable automated health coaching systems. First, I utilized computational approaches that leverage individuals’ self-tracking and health data and used an expert system to translate ML inferences into personalized nutrition goal recommendations. The system, GlucoGoalie, was evaluated in multiple studies including a 4-week deployment study which demonstrated the feasibility of the approach. Second, I compared human-powered and automated/chatbot approaches to health coaching in a 3-week study which found that t2.coach — a scripted, theoretically-grounded chatbot designed through an iterative, user-centered process — cultivated a coach-like experience that had many similarities to the experience of messaging with actual health coaches, and outlined directions for automated, conversational coaching interventions. Third, I examined multiple AI approaches to enable micro-coaching dialogs — brief coaching conversations related to specific meals, to support achievement of nutrition goals — including a knowledge-based system for natural language understanding, and a data-driven, reinforcement learning approach for dialog management. Together, the results of these studies contribute methods and insights that take steps towards more intelligent conversational coaching systems, with resonance to research in informatics, human-computer interaction, and health coaching.

Chronic diseases are among the leading causes of death globally, and as much as 80% of these deaths are reported to be preventable with proper diet and lifestyle. Although extensive research has demonstrated that the increased consumption of fruits and vegetables offers protective health effects from many chronic illnesses, populations in both developed and developing nations consistently fall short of the recommended intake of 5 or more servings a day. This study investigated the effects of daily consumption of Green Smoothies for 4 consecutive weeks on blood pressure and health-related quality of life. Green Smoothies are a blended drink consisting of fruit, leafy greens and water. The study was a randomized controlled trial with a final sample of 29 volunteer participants. Data were collected at baseline and post-intervention and included anthropometric and physiologic measures, as well as a nutrition survey. The treatment group demonstrated trends toward improvements in waist circumference (p = 0.026), waist-to-hip ratio (p = 0.05), and symptoms of burden linked to diet (p = 0.04), small intestine (p = 0.04), large intestine (p = 0.05), and mineral needs (p = 0.04). Despite the lack of statistically significant reductions in blood pressure, the trend toward improvements in waist circumference and waist-to-hip ratio are considered to be useful and informative of health risk. Thus, the results of this study provide preliminary support for the consumption of Green Smoothies as a possible primary prevention effort for chronic conditions. It may also help to reduce health risks or even reverse the effects of chronic conditions.

This study was done with the objective of designing and applying a nutrition education program based on a test of improved practices for pregnant women and women of childbearing age in the rural communities of Ibarra canton: La Riconada and Cuambo. For this, information was collected on knowledge, attitudes, and practices (KAP) regarding the eating habits of pregnant women. These results were used to identify content and recommendations to reinforce and/or instruct about eating during pregnancy. Nutrition education was based on the methodology of the improved practices test, which consisted of testing the recommendations in families' homes before recommending them and recording information on their acceptability. The results indicate that pregnant women in the two communities don't eat all the food groups every day. They need to increase the consumption of foods rich in calcium and iron, as well as foods that supply energy, protein, and fats. The pregnant women don't eat additional foods to cover these recommendations during the pregnancy. Despite the knowledge they have and the lessons they received, there are women who don't eat greens, vegetables, and fruits because they don't like them, and those who do eat them don't meet the established nutritional recommendations. The women prefer to eat artificial drinks with unboiled water, and they do not look after personal hygiene. The test of improved practices has been useful for observing if they really put in practice the knowledge about eating during pregnancy, and at the same time it helped design the educational proposal that served as a guide to help improve eating practices of pregnant women in the two rural communities, considering their motivations and recommendations.

No description available.

Fifty twelve-month female Sprague-Dawley rats were used to study a lysine requirement for tissue maintenance. Animals were randomly assigned into five groups with dietary lysine levels ranging from 0.097 to 0.317 percent and fed for 60 days. Liver composition and carcass composition were determined, and a lysine requirement was also predicted. Results showed that the group fed 0.317 percent lysine had significantly increased liver fat content and decreased protein content. Neither liver moisture content nor total liver nitrogen content was related to dietary lysine levels. There was no significant finding on the analysis of carcass composition. The data indicated that the mature rat had a requirement for lysine lower than 0.097 percent in the diet. It was suggested that either adequate lysine was provided by wheat gluten in the diet, or the mature rat did not require lysine in order to maintain tissue level of protein. In future studies, it was necessary to use a diet with lysine levels lower than 0.097 percent to determine the minimum lysine requirement, and a concurrent baseline group for comparison with the treatment animals. / M.S.

To study the effect of exercise and protein intake during pregnancy on maternal and fetal zinc status in the rat, one hundred and seventy-nine pregnant Sprague-Dawley rats were divided into four groups; sedentary-standard protein diet, sedentary-high protein diet, exercising-standard protein diet and exercising-high protein diet. The standard protein diet contained 7.22% protein, while the high protein diet contained 24.77% protein; all other nutrients were supplied in amounts required for normal parturition of the laboratory rat. After acclimatization, the exercising dams, regardless of diet, were made to swim continuously for one and one-half hours/day until sacrifice. The four major groups were further subdivided into 28 groups, designated by three-day intervals according to gestational day--days 3, 6, 9, 12, 15, 18, and 21. Uterine tissues were retained for zinc content analysis; fetal and placental tissues were separated from uterine tissue for days 15 through 21 only. The concentration of uterine zinc was affected solely by gestation; absolute placental tissue zinc values were lowest in the sedentary-high and exercising-low protein groups, while the exercising-high protein group possessed the greatest zinc value. No significant difference was detected in fetal zinc concentrations. Fetal tissue from exercising dams weighed significantly less (p<0.05) than fetal tissue from the sedentary dams; and sedentary-high protein dams produced significantly more (p<0.05) fetuses than the exercising-high protein dams. Both protein intake and exercising during pregnancy significantly affect normal parturition and zinc metabolism in the rat. / M.S.

The effect of two levels of dietary protein and exercise on iron metabolism in pregnant Sprague-Dawley rats was studied. Animals were assigned to the following diet and exercise groups on the first day of gestation: high protein sedentary (HS), high protein exercise (HEx), low protein sedentary (LS), low protien exercise (LEx). Animals in the exercise groups swam continuously for 75 minuites the first day and 90 minutes daily thereafter, throughout the study. Hemoglobin, hematocrit, liver iron concentration and spleen iron concentration were measured at day 0, 3, 6, 9, 12, 15, 18, and 21 of gestation. Mean hemoglobin, hematocrit and liver iron concentration values were lower at day 21 than at day 0 of gestation. Mean hematocrit and hemoglobin for the LEx group were the lowest for days 9 through 15. At day 15 the mean hematocrit for the LEx group was significantly (p < 0.05) lower than that of the other groups. The HEx group had the highest hematocrit and hemoglobin values at day 21 of gestation; hemoglobin was significantly (p < 0.05) higher. No difference in mean spleen iron concentration from day 0 to day 21 was found, however, the low protein groups had higher spleen iron values early in pregnancy that the high protein groups. The mean spleen iron concentration of the LEx group was significantly (p < 0.05) higher than those of the HS and HEx groups at day 6. A trend for higher liver iron concentration values of the low protein groups than high protein groups was also observed. The LEx group had a significantly (p <0.05) higher mean liver iron concentration at day 18 than the other groups. Both protein nutriture and exercise appear to affect iron metabolism in pregnant rats. / M.S.

Thesis (MScMedSc) -- Stellenbosch University, 2001. / ENGLISH ABSTRACT: Osteopenia is a well documented complication of anorexia nervosa (AN). The pathogenesis of this bone loss is presently poorly defined in the literature. Pathogenetic mechanisms that have been implicated include certain nutritional factors, exercise abuse, hypogonadism, hypercortisolism and/or vitamin 0 deficiency. We studied, 59 Caucasian eating disorder patients aged 15-45yr. The eating disorder was classified by a single, qualified psychiatrist according to OSM IV R criteria as either anorexia nervosa (AN: n =25), bulimia nervosa (BN: n = 17) or eating disorder not otherwise specified (EONOS: n = 17). All patients were subjected to a detailed dietary and general history. We assessed the prevalence and severity (OEXA), the nature (osteocalcin, deoxypyridinoline) and site (vertebral versus hip) of osteopenla in these patients. he role of nutritional factors (energy intake, weight, height, BMI, plasma albumin, lipids), physical activity, hypercortisolemia (plasma and urinary free cortisol), vitamin 0 deficiency (plasma 250HD) and hypogonadism (amenorrhoea, E2, LH, FSH) in the pathogenesis of bone loss were also evaluated. Mild osteopenia (BMO decreased by more than 1SO below age-matched controls) was documented in 46% of the total study population, with more marked osteopenia (Z-Score < -2 SO) present in 15%. Both vertebral and hip osteopenia were documented. In the study population those patients with AN (Lumbar BMO (q/cm") = 0.869 ± 0.121) were most likely to develop osteoporosis, although a significant percentage of patients with BN (Lumbar BMO (q/crn") = 0.975 ± 0.16) and EONOS (Lumbar BMO (g/cm2) = 0.936 ± 0.10) were also osteopenic (29% and 35% respectively). Twenty four percent (24%) of the total patient population had a history of fragility fractures. These fractures were reported more commonly amongst patients with AN and EONOS (28% and29.4%). Fracture prevalence was however similar in patients with normal and low bone mass. Conventional risk factors were similar in patients with normal and low bone mass, except for a significantly longer duration of amenorrhoea (p = 0.009), a lower BMI (p = 0.0001) and greater alcohol consumption (p = 0.05) in the osteopenic patients. Nutritional parameters (S-albumin, protein, Ca, and P04 intakes), physical activity, as well as 25(OH) vitamin D levels were similar in AN and BN subjects, as well as in patients with a low versus normal BMD. Plasma and urine cortisol levels were also similar in these subgroups. With the exception of two patients with borderline osteopenia, significant bone loss was only documented in those patients with a past or current history of amenorrhoea. In the total patient population the duration of amenorrhoea was significantly (p<0.009) longer in patients with osteopenia versus those with a normal bone mass. A significant negative correlation between BMD (Z-Score) and duration of amenorrhoea was also documented in the total patient population (r = -0.4, P = 0.001) as well as in all three eating disorder groups (AN r - -0.4, P = 0.03; BN r = - 0.6, P = 0.008; EDNOS r = -0.6, P = 0.005). In the total patient population, those patients with amenorrhoea, had lower BMD and BMI values and lower estrogen levels compared to those with a normal menstrual cycle. We conclude that osteopenia commonly attends AN, as well as BN and EDNOS. Nutritional (with the exception of alcohol consumption) and mechanical factors as well as hypercortisolemia did not appear to contribute significantly to bone loss in this study population. Hypogonadism appeared to be the main cause of the bone loss observed in these patients. / AFRIKAANSE OPSOMMING: Osteopenie is In welbekende komplikasie van anorexia nervosa (AN). Die patogenese van hierdie beenverlies is swak in die huidige literatuur omskryf en nutrisiele faktore, 'n vita mien 0 gebrek, oormatige oefening, hiperkortisolemie en hipogonadisme word onder andere qeimpliseer. Vir die doel van die studie is In totaal van 59 Kaukasier eetsteurnis pasiente patients volledig ondersoek. Die tipe eetsteurnis is deur In enkel gekwalifiseerde psigiater volgens die DSM IV R kriteria geklassifiseer as anorexia nervosa (AN: n =25) of bulimia nervosa (BN: n = 17) of eetsteurnis nie anders gespesifiseer (EDNOS: n = 17). Elke pasient is ook aan In gedetailleerde dieet en algemene risikofaktor vraelys vir osteoporose onderwerp. Die voorkoms en graad (DEXA), die aard (osteokalsien, deoksipiridinolien) asook die tipe (werwelkolom/heup) osteopenie is ondersoek. Die rol van nutrisiele faktore (totale kalorie-inmame, gewig ,Iente LMI, plasma albumien, lipiede) en vitamien 0 gebrek, oefening, hiperkortisolemie (plasma en urinere kortisol) en hipogonadisme (amenoree, plasma E2, LH,FSH) in die patogenese van die beenverlies is ook evalueer. Matige osteopenie (BMD meer as 1 SO onder die van ouderdomskontrole) is in 46% van die totale pasientpopulasie gedokumenteer, met erge osteopenie (Z-Telling < -2) in 15%. Aantasting van beide werwelkolom en heup is aangetoon. In hierdie studiepopulasie kom osteopenie meer algemeen voor in die AN (Lumbaal BMD (g/cm2) = 0.869 ± 0.121) groep (64%) in vergelyking met BN (Lumbaal BMD (g/cm2) = 0.975 ± 0.16) (29%) en (EDNOS) (Lumbaal BMD (g/cm2) = 0.936 ± 0.10) (32%). Vier-en-twintig persent van die totale pasientpopulasie het In geskiedenis van frakture gehad. Frakture het meer algemeen in AN en EDNOS pasiente voorgekom (28% en 29%). Pasiente met 'n lae beenmassa was gekenmerk deur In betekenisvolle laer LMI (p = 0.0001), hoer alkolholverbruik (p = 0.05) en langer duurte van amenoree(p = 0.009). Nutrisiele parameters (s-albumien, protetene, Ca, P04 inname) oefening, asook 25(OH) vitamien 0 vlakke was soortgelyk in AN en BN pasiente. Hierdie parameters het ook nie verskil tussen pasiente met osteopenie en die met In normale BMD nie. Plasma en urinere vry kortisolvlakke was ook soortgelyk in hierdie twee groepe. Betekenisvolle beenverlies (met die uitsondering van twee pasiente met grenslyn osteopenie) het slegs voorgekom in pasiete met 'n huidige of In vorige geskiedenis van amenoree. In die totale pasientpopulasie was die duurte van amenoree (p< 0.009) betekenisvollanger in die pasiente met osteopenie. In Betekenisvolle negatiewe korrelasie tussen BMD (Z-Telling) en die duurte van amenoree in die toale pasient populasie (r = -0.4; P = 0.001) asook in al drie eetsteurnis groepe (AN: r = -0.4; P = 0.03; BN: r = -0.06; P = 0.008; EDNOS: r = - 0.6, P = 0.005) is aangetoon. In die groep as 'n geheel, het die amenoree pasiente In laer LMI, E2vlakke en BMD gehad in vergelyking met die pasiente met normale menses. Opsommend dus, kom osteopenie algemeen in pasiente met AN, asook BN en EDNOS voor. In Betekenisvolle bydrae van nutrisiele (met die uitsondering van alkoholinname) en meganiese faktore asook hiperkortisolemie tot been verlies, kon nie in hierdie tudie populasie gedemonstreer word nie. Hipogonadisme is as die hoofoorsaak van osteopenie in die pasiente qefdentifiseer.