The polyp prevention trial II: dietary intervention program and participant baseline dietary characteristics.

The Polyp Prevention Trial (PPT) is a multicenter randomized controlled trial to evaluate whether a low-fat, high-dietary fiber, high-fruit and -vegetable eating pattern will reduce the recurrence of adenomatous polyps of the large bowel. Men and women who had one or more adenomas removed recently were randomized into either the intervention (n = 1037) or control (n = 1042) arms. Food frequency questionnaire data indicate that PPT participants at the beginning of the trial consumed 36.8% of total energy from fat, 9.7 g of dietary fiber/1000 kcal, and 3.8 daily servings of fruits and vegetables. Baseline dietary characteristics, including intake of fat, fiber, and fruits and vegetables, as well as other macro- and micronutrients, were similar in the two study groups. The intervention participants receive extensive dietary and behavioral counseling to achieve the PPT dietary goals of 20% of total energy from fat, 18 g/1000 kcal of dietary fiber, and 5-8 daily servings (depending on total caloric intake) of fruits and vegetables. Control participants do not receive such counseling and are expected to continue their usual intake. Dietary intake in both groups is mentioned annually using a 4-day food record (also completed at 6 months by intervention participants only) and a food frequency questionnaire, with a 10% random sample of participants completing an annual unscheduled 24-h telephone recall. Blood specimens are drawn and analyzed annually for lipids and carotenoids. This article provides details on the rationale and design of the PPT dietary intervention program and describes the participant baseline dietary intake data characteristics.

Internal locus of control and social support associated with some dietary changes by elderly participants in a diet intervention trial.

OBJECTIVE: Measure relationships of locus of control and social support to diet changes in an intervention trial. DESIGN: Participants in the Polyp Prevention Trial (PPT) completed Multidimensional Health Locus of Control (MHLC) and Norbeck Social Support Questionnaires (NSSQ) and modified Block food frequency questionnaires. Data were collected at baseline and 1 year later. SUBJECTS/SETTING: A convenience sample of PPT intervention (N = 68) and control (n = 43) participants at 1 clinical center participated in this ancillary study. MAIN OUTCOME MEASURES: Mean daily dietary intakes after 1 year were compared with baseline values. Intervention participants' scores for MHLC internal locus of control and NSSQ total functional network were correlated with diet changes. STATISTICAL ANALYSES PERFORMED: Group percentages were compared using the Fisher exact test; means were compared by t test. RESULTS: Groups were comparable in demographics, baseline diet, and scores for internal locus of control and total functional network. Intervention group participants made greater diet changes than control participants in intake of fat (-27 g vs -8 g), fat as a percentage of kilocalories (-8% vs -2%), fiber as grams per 1,000 kcal (7 g vs 0.3 g), and daily fruit/vegetable servings (2.0 vs 0.2). Pearson correlations of diet changes with internal locus of control scores (all P > .05) were fat grams, r = 0.031; fat as percentage of kilocalories, r = 0.023; fiber grams per 1,000 kcal; r = 0.230; and fruit/vegetable servings, r = 0.186. Correlations with total functional network scores were: fat grams, r = 0.022 (P > .05); fat as percentage of kilocalories, r = -0.108 (P > .05); fiber grams per 1,000 kcal, r = 0.276, P < .05; and daily fruit/vegetable servings, r = 0.326, P < .05. APPLICATIONS/CONCLUSIONS: Intensive and skillful dietary intervention can succeed whether or not clients bring strong internal locus of control or social support to the diet change program.

Influence of exercise on NA- and Hsp72-induced release of IFNγ by the peritoneal suspension of macrophages and lymphocytes from genetically obese Zucker rats.

Regular physical exercise is recognized as a nonpharmacological therapeutic strategy in the treatment of metabolic syndrome, and has been proposed for improving obesity, diabetic status, insulin resistance, and immune response. The aim of the present study was to evaluate the effect of a regular exercise program (treadmill running, 5 days/week for 14 weeks at 35 cm/s for 35 min in the last month) on the release of the pro-inflammatory cytokine interferon gamma (IFNγ) by peritoneal cells (macrophages and lymphocytes) from obese Zucker rats (fa/fa) in response to noradrenaline (NA) and heat shock proteins of 72 kDa (Hsp72), and the possible adaptation due to training for a bout acute exercise (a single session of 25-35 min at 35 cm/s). In healthy (lean Fa/fa) and obese animals, peritoneal cells released greater concentrations of IFNγ in response to Hsp72 and lower concentrations in response to NA. The regular exercise training protocol, evaluated in the obese animals, produced a clear change in the regulation of the release of IFNγ. Peritoneal immune cells from trained animals released more IFNγ in response to NA, but there was a reduction in the release of IFNγ in response to Hsp72. In the obese animals, regular exercise caused a change in the inhibitory effect of NA (which now becomes stimulatory) and the stimulatory effect of Hsp72e (which now becomes inhibitory) in relation to the release of IFNγ. This reflects that Hsp72, induced by the prior release of NA following exercise-induced stress, plays a role in the homeostatic balance of release of IFNγ by peritoneal immune cells in obese animals during exercise.