Fecal beta-sitosterol in patients with diverticular disease of the colon and in vegetarians

Dietary pattern and its association with right-colonic diverticulosis

BACKGROUND AND AIM

In East Asia, colonic diverticulosis develops most commonly in the right colon and is known to have different characteristics compared with left-sided one. This study was designed to investigate whether right-colonic diverticulosis is associated with posteriori dietary patterns.

METHODS

We retrospectively reviewed medical records of prospectively collected cohort that received health check-up in Korea between May 2011 and January 2012. Their anthropometric data, biochemical results, medication history, underlying diseases, colonoscopic findings, and dietary data obtained from semi-quantitative food-frequency questionnaire were analyzed. Three dietary patterns were identified using factor analysis: healthy dietary pattern (vegetables, fish, seaweed, fruits, and beans), meat dietary pattern (red meat, processed meat/fish, fried noodle, poultry, and cephalopods), and snack dietary pattern (bread, sweets, dairy products, nuts, and rice cake).

RESULTS

Out of the total 1911 patients, 203 (10.6%) had right-colonic diverticulosis, 21 (1.1%) had pan-colonic diverticulosis, and 12 (0.6%) had left-colonic diverticulosis. Among the total, none of the three patterns were associated with right-colonic diverticulosis, under adjustment with age, gender, body mass index, metabolic syndrome, and total energy intake. However, among women, meat dietary pattern was positively associated with right-colonic diverticulosis (odds ratio 1.866, 95% confidence interval: 1.0983-3.173, P = 0.021).

CONCLUSION

This study demonstrated that meat dietary pattern is positively associated with right-colonic diverticulosis among women.

High intake of dietary fibre from fruit and vegetables reduces the risk of hospitalisation for diverticular disease

BACKGROUNDS AND AIMS

High intake of dietary fibres has been associated with a reduced risk of DD. However, reports on which type of dietary fibre intake that is most beneficial have been conflicting. The aim of this study was to investigate the association between different dietary fibres and hospitalisation due to diverticular disease (DD) of the colon.

METHODS

This was a major cohort study. The Swedish Mammography Cohort and the Cohort of Swedish Men were linked to the Swedish Inpatient Register and the Causes of Death Register. Data on the intake of dietary fibre were collected through questionnaires. The effect of intake (in quartiles) of different types of dietary fibre on the incidence of hospitalisation due to DD was investigated using multivariable Cox regression. Estimates were adjusted according to age, BMI, physical activity, co-morbidity, intake of corticosteroids, smoking, alcohol intake and education level.

RESULTS

Women with intake of fruit and vegetable fibres in the highest quartile (median 12.6 g/day) had a 30% decreased risk of hospitalisation compared to those with the lowest intake (4.1 g/day). Men within the highest quartile (10.3 g/day) had a 32% decreased risk compared to those with a low intake (2.9 g/day). High intake of fibres from cereals did not affect the risk.

CONCLUSION

A high intake of fruits and vegetables may reduce the risk of hospitalisation due to DD. Intake of cereals did not influence the risk.

Critical Analysis on Characterization, Systemic Effect, and Therapeutic Potential of Beta-Sitosterol: A Plant-Derived Orphan Phytosterol

Beta-sitosterol (BS) is a phytosterol, widely distributed throughout the plant kingdom and known to be involved in the stabilization of cell membranes. To compile the sources, physical and chemical properties, spectral and chromatographic analytical methods, synthesis, systemic effects, pharmacokinetics, therapeutic potentials, toxicity, drug delivery and finally, to suggest future research with BS, classical as well as on-line literature were studied. Classical literature includes classical books on ethnomedicine and phytochemistry, and the electronic search included Pubmed, SciFinder, Scopus, the Web of Science, Google Scholar, and others. BS could be obtained from different plants, but the total biosynthetic pathway, as well as its exact physiological and structural function in plants, have not been fully understood. Different pharmacological effects have been studied, but most of the mechanisms of action have not been studied in detail. Clinical trials with BS have shown beneficial effects in different diseases, but long-term study results are not available. These have contributed to its current status as an "orphan phytosterol". Therefore, extensive research regarding its effect at cellular and molecular level in humans as well as addressing the claims made by commercial manufacturers such as the cholesterol lowering ability, immunological activity etc. are highly recommended.

A high-fiber diet does not protect against asymptomatic diverticulosis

BACKGROUND & AIMS

The complications of diverticulosis cause considerable morbidity in the United States; health care expenditures for this disorder are estimated to be $2.5 billion per year. Many physicians and patients believe that a high-fiber diet and frequent bowel movements prevent the development of diverticulosis. Evidence for these associations is poor. We sought to determine whether low-fiber or high-fat diets, diets that include large quantities of red meat, constipation, or physical inactivity increase risk for asymptomatic diverticulosis.

METHODS

We performed a cross-sectional study of 2104 participants, 30-80 years old, who underwent outpatient colonoscopy from 1998 to 2010. Diet and physical activity were assessed in interviews using validated instruments.

RESULTS

The prevalence of diverticulosis increased with age, as expected. High intake of fiber did not reduce the prevalence of diverticulosis. Instead, the quartile with the highest fiber intake had a greater prevalence of diverticulosis than the lowest (prevalence ratio = 1.30; 95% confidence interval, 1.13-1.50). Risk increased when calculated based on intake of total fiber, fiber from grains, soluble fiber, and insoluble fiber. Constipation was not a risk factor. Compared to individuals with <7 bowel movements per week, individuals with >15 bowel movements per week had a 70% greater risk for diverticulosis (prevalence ratio = 1.70; 95% confidence interval, 1.24-2.34). Neither physical inactivity nor intake of fat or red meat was associated with diverticulosis.

CONCLUSIONS

A high-fiber diet and increased frequency of bowel movements are associated with greater, rather than lower, prevalence of diverticulosis. Hypotheses regarding risk factors for asymptomatic diverticulosis should be reconsidered.

Diverticular disease of the colon: New perspectives in symptom development and treatment

Diverticular disease of the colon is a common disease worldwide. Although the disease is asymptomatic in about 70%-80% of patients, it represents, at least in Western countries, one of the most important gastrointestinal diseases in terms of direct and indirect health costs. Pathogenesis of the disease is still unknown. However, it is the result of complex interactions between colonic structure, intestinal motility, diet and genetic factors. Whilst efficacious preventive strategies remain to be identified, fibre supplementation in the diet is recommended. Why symptoms develop is still unclear. Results of recent experimental studies on irritable bowel syndrome speculated that low grade inflammation of colonic mucosa, induced by changes in bacterial microflora, could affect the enteric nervous system, which is crucial for normal gut function, thus favouring symptom development. This hypothesis could be extrapolated also for diverticular disease, since bacterial overgrowth is present, at least in a subgroup of patients. These perspectives on symptom development are reviewed and new therapeutic approaches are hypothesized.

A prospective study of dietary fiber types and symptomatic diverticular disease in men

To examine prospectively dietary fiber calculated from food composition values based on analytic techniques and specific dietary fiber types in relation to risk of diverticular disease, we analyzed data from a prospective cohort of 43,881 U.S. male health professionals 40-75 y of age at base line; subjects were free of diagnosed diverticular disease, colon or rectal polyps, ulcerative colitis and cancer. The insoluble component of fiber was inversely associated with risk of diverticular disease relative risk (RR) = 0. 63, 95% confidence interval (CI), 0.44-0.91, P for trend = 0.02, and this association was particularly strong for cellulose (RR = 0.52, 95% CI, 0.36-0.75, P for trend = 0.002). The association between diverticular disease and total dietary fiber intake calculated from the AOACstandards method was not appreciably different from results using the Southgate or Englyst method [for AOAC method, RR = 0.60, 95% CI, 0.41-0.87; for Southgate method, RR = 0.61, 95% CI, 0.42-0. 88; for Englyst method, RR = 0.60, 95% CI, 0.42-0.87, for the highest quintiles]. Our findings provide evidence for the hypothesis that a diet high in dietary fiber decreases the risk of diverticular disease, and this result was not sensitive to the use of different analytic techniques to define dietary fiber. Our findings suggest that the insoluble component of fiber was significantly associated with a decreased risk of diverticular disease, and this inverse association was particularly strong for cellulose.

A prospective study of alcohol, smoking, caffeine, and the risk of symptomatic diverticular disease in men

The relationship between smoking, caffeine, and alcohol intake and the risk of symptomatic diverticular disease has not been investigated directly. We examined these associations in a prospective cohort of 47,678 US men, 40 to 75 years old. During 4 years of follow-up (1988 to 1992), we documented 382 newly diagnosed cases of symptomatic diverticular disease. After adjustments for age, physical activity, and energy-adjusted intake of dietary fiber and total fat, alcohol intake (comparing those who drink > 30 g of alcohol/d to nondrinkers) was only weakly and nonsignificantly associated with risk of symptomatic diverticular disease (relative risk (RR) = 1.36; 95 percent confidence interval (CI), 0.94 to 1.97; P for trend = 0.37). We observed no association between caffeine, specific caffeinated beverages, and decaffeinated coffee and the risk of symptomatic diverticular disease. Current smoking was not appreciably associated with risk of symptomatic diverticular disease compared to nonsmokers (RR = 1.25; 95 percent CI, 0.75 to 2.09) after adjustment for age, physical activity, and energy-adjusted intake of dietary fiber and total fat. In a subset analysis restricted to men who had undergone sigmoidoscopy or colonoscopy, a modest positive association was seen between smoking and risk of symptomatic diverticular disease. These results suggest that smoking, caffeine, and alcohol intake are not associated with any substantially increased risk of symptomatic diverticular disease.

Prospective study of physical activity and the risk of symptomatic diverticular disease in men

The relationship between physical activity and risk of symptomatic diverticular disease has not been investigated directly. This association was examined in a prospective cohort of 47,678 American men, 40 to 75 years of age, and free of diagnosed diverticular disease, colon or rectal polyp, ulcerative colitis, and cancer before 1988. During four years of follow up, 382 newly diagnosed cases of symptomatic diverticular disease were documented. After adjustment for age, energy adjusted dietary fibre, and energy adjusted total fat, overall physical activity was inversely associated with the risk of symptomatic diverticular disease (for highest versus lowest extremes, relative risk (RR) = 0.63 (95% confidence interval (CI) 0.45, 0.88). Most of the inverse association was attributable to vigorous activity, for extreme categories RR = 0.60 (95% CI 0.41, 0.87). For activity that was not vigorous the RR was 0.93 (95% CI 0.67, 1.69). Several specific activities were inversely associated with the risk of diverticular disease, but jogging and running combined was the only individual activity that was statistically significant (p for trend = 0.03). For men in the lowest quintile for dietary fibre intake and total physical activity (compared with those in the opposite extreme), the RR was 2.56 (95% CI 1.36, 4.82). Physical activity, along with a high fibre diet, may be an important factor in the prevention of symptomatic diverticular disease.

Fecal steroids and colorectal cancer

The fecal steroid profiles of healthy subjects were compared with those of colorectal cancer (CRC) patients. The multicomponent profiles did not differ qualitatively in that CRC patients, like control subjects, had similar fecal steroids. The major bile acids detected in fecal extracts were lithocholic acid (LCA) and deoxycholic acid (DCA). The major sterol of animal origin was cholesterol and its bacterial metabolite coprostanol, whereas the major plant sterols were beta-sitosterol, stigmasterol, campesterol, and their corresponding bacterial metabolites. CRC patients excreted higher amounts of total major bile acids (LCA and DCA) than did the control group, but this difference was not significant. However, the LCA-to-DCA ratio was much higher in the CRC group [(1.43, p less than 0.01) compared with the control group (0.72)]. The control group excreted significantly higher amounts of total neutral sterols (p less than 0.001), sterols of animal origin (p less than 0.001), and plant sterols (p less than 0.001) compared with the CRC group; the plant sterols represented a much lower proportion of excreted total neutral sterols in the CRC group (p greater than 0.001) compared with the control group. We propose the following hypotheses. The LCA-to-DCA ratio may be an important discriminant market for CRC susceptibility. The fecal LCA-to-DCA ratio may depend on the differential hepatic synthesis of their respective precursors chenodeoxycholic acid (CDCA) and cholic acid. Hepatic synthesis of CDCA may be increased by more efficient conservation of dietary cholesterol because it has been shown that cholesterol of exogenous origin is the main precursor of this bile acid.(ABSTRACT TRUNCATED AT 250 WORDS)

Bowel function measurements of individuals with different eating patterns

Bowel function was assessed in 51 subjects: 10 women and seven men who habitually consumed an omnivorous, vegetarian, or vegan diet. The subjects on these diets had a mean intake of fibre of 23 g, 37 g, and 47 g respectively. Mean transit times were variable and not significantly different between the groups. Vegans, however, had a greater frequency of defecation and passed softer stools. All measurements of bowel function were significantly correlated with total dietary fibre. As dietary fibre increased mean transit time decreased, stool frequency increased and the stools became softer. Men produced a greater quantity of softer, less formed faeces than women. During the luteal phase of the menstrual cycle women excreted harder stools and had a significantly longer mean transit time. The finding that mean transit time was more highly correlated with faecal form than any of the other bowel function measurements could be of practical importance.

The kinetics of the protective effect of beta-sitosterol against MNU-induced colonic neoplasia

The effect of dietary supplementation with beta-sitosterol (0.2% of diet) was followed in Fischer rats after both acute and chronic feeding. Compared to controls after 3 and 7 days, the number of epithelial cells per crypt column in both plant sterol fed groups was shifted to lower values; moreover, fewer cells above cell position 12 were engaged in DNA synthesis. Continued feeding of beta-sitosterol for 28 weeks revealed the number and position of 3HTdR-labeled cells per crypt column after 1 pulse labeling to be similar to that seen in the acute phase. However, differences were more marked after 24 h showing the maximum number of labeled cells per column to be at least 25% less than the untreated group and the leading edge of labeled cells moving more slowly up the crypt wall. Rats treated with N-methyl-N-nitrosourea (MNU) intrarectally (8 mg/animal) while simultaneously consuming beta-sitosterol demonstrated a reduction in the size of the proliferative compartment as well as the number of labeled cells per crypt column as compared to rodents receiving just the carcinogen (3.3 and 5.4 mean labeled cells per column, respectively). At this time, MNU-treated rats fed beta-sitosterol had a significantly decreased colonic tumor incidence (Raicht et al. 1980). This plant sterol which passes through the digestive tract relatively unabsorbed appears to slow colonic epithelial cell proliferation resulting in a reduced expression of neoplastic transformation.