Aleurone flour increases red-cell folate and lowers plasma homocyst(e)ine substantially in man

Aleurone flour (ALF) is a rich source of natural folate (>500 microg/100 g wet weight). Our objective was to establish whether intake of ALF in man can significantly improve folate status and reduce plasma homocyst(e)ine. We performed a randomised, controlled intervention, of 16 weeks duration, in free-living healthy individuals (mean age 46-52 years). Participants were assigned to one of three groups: ALF, 175 g bread made with ALF and placebo tablet each day; PCS, 175 g bread made with pericarp seed coat (PCS) flour and placebo tablet each day (low-folate control); or FA, 175 g bread made with PCS flour and tablet containing 640 microg folic acid each day (high-folate control). The daily folate intake contributed by the bread and tablet was 233 microg in the PCS group, 615 microg in the ALF group and 819 microg in the FA group. The number of participants completing all phases of the PCS, ALF and FA interventions was twenty-five, twenty-five and eighteen, respectively. Plasma and red-cell folate increased significantly (P<0.0001) and plasma homocyst(e)ine decreased significantly (P<0.0001) in the ALF and FA groups only. Plasma folate and red-cell folate in the ALF group (mean, 95 % CI) increased from baseline values of 12.9 (9.9, 15.7) nmol/l and 509 (434, 584) nmol/l to 27.1 (22.5, 31.7) nmol/l and 768 (676, 860) nmol/l, respectively. Plasma homocyst(e)ine in the ALF group decreased from 9.1 (8.2, 10.0) micromol/l at baseline to 6.8 (6.2, 7.5) micromol/l after 16 weeks. In conclusion, moderate dietary intake of ALF can increase red-cell folate and decrease plasma homocyst(e)ine substantially.     

C-terminal octapeptide of cholecystokinin decreases food intake in man

In comparison with a saline infusion, the infusion of the C-terminal octapeptide of cholecystokinin (4 ng/kg/min) decreased food intake by an average of 122 g in a group of 12 lean men without objective evidence of untoward side effects. Shapes of the cumulative intake curves under the two conditions were similar, but subjects ate less and stopped eating sooner when receiving octapeptide than when receiving saline. These results are consistent with the hypothesis that cholecystokinin is an endogenous signal for postprandial satiety. The results offer promise for the possible use of the octapeptide as an appetite suppressant.     

Medium-chain triacylglycerols enhance release of cholecystokinin in chicks.

Whether medium-chain triacylglycerols (MCT) affect the plasma concentration of cholecystokinin (CCK) and crop-emptying rate in chicks was investigated after 0, 30, 60, 90, 120 or 180 min of diet intubation. Triacylglycerol sources used were corn oil [containing long-chain triacylglycerols (LCT)], glyceryl tricaprate and glyceryl tricaprylate at a level of 200 g/kg diet. Plasma CCK concentration was significantly enhanced in chicks given the two MCT treatments, but not in those given the LCT treatment, after 30 min feeding relative to the initial level. At all time points, chicks fed the diet containing LCT had significantly lower plasma CCK concentrations than those fed MCT, and chicks fed glyceryl tricaprate had higher concentrations than those fed glyceryl tricaprylate. Dietary MCT sources significantly delayed diet passage from the crop compared with dietary LCT. These results indicate that MCT are more potent stimulators of CCK secretion in chicks than LCT.     

Coffee stimulation of cholecystokinin release and gallbladder contraction in humans

We studied the effect of the ingestion of 400 mL regular coffee on plasma cholecystokinin (CCK) concentrations and of 165 mL regular and decaffeinated coffee on plasma CCK and gallbladder contraction in six healthy regular coffee drinkers. Plasma CCK concentrations rose 3.3 +/- 0.4 pmol/L after 400 mL and 2.8 +/- 0.9 pmol/L after 165 mL regular coffee compared with 1.8 +/- 0.6 pmol/L after 165 mL decaffeinated coffee. These plasma CCK increments were greater than those after 400 and 165 mL of an isosmotic and isothermic sodium chloride solution (0.6 +/- 0.2 and 0.4 +/- 0.1 pmol/L, respectively). An average gallbladder contraction of 33 +/- 7% was observed after 165 mL regular coffee and 29 +/- 10% after 165 mL decaffeinated coffee, whereas after 165 mL sodium chloride the contraction was only 10 +/- 12%. We conclude that both regular coffee and decaffeinated coffee give rise to increments in plasma CCK and contractions of the gallbladder.     

Growth, digestibility, and enzyme activities in the pancreas and intestines of guinea-pigs fed on raw and heated soya-bean flour

The nutritional effects of giving raw (RSF) or heated (HSF) soya-bean flour to young guinea-pigs were investigated in trials 1 and 2, in which the levels of dietary protein were 120 and 190 g/kg diet respectively. The growth rate of animals fed on RSF was lower than that of those fed on HSF. Growth retardation of guinea-pigs fed on RSF was accompanied by a lower apparent digestibility of the protein (0.49-0.53) compared with HSF (0.67-0.76) and lower food conversion efficiency. In RSF-fed animals, increasing dietary protein affected growth and food conversion efficiency negatively. The pancreas of animals fed on RSF and HSF was similar in weight but secreted less trypsin, chymotrypsin and amylase, in RFS-fed animals. It was concluded that the mechanism by which raw soya-bean negatively affects the growth rate of guinea-pigs by reducing the activity of intestinal enzymes, differs from that suggested for rats and chicks, but is similar to that of pigs and calves.     

Effect of intravenous fat on cholecystokinin secretion and gallbladder motility in man.

During total parenteral nutrition (TPN) gallbladder bile stasis and hypomotility have been well documented. Little is known, however, about the effect of the separate components of TPN on gallbladder motor function. Inasmuch as fat, administered intraduodenally, is a potent stimulus of cholecystokinin (CCK) secretion and gallbladder contraction we have investigated whether intravenous (IV) fat affects gallbladder motility. Six healthy volunteers were studied on two separate occasions, during infusion of Intralipid 10%, 200 mL/h or saline infusion (control) for 3 hours, to evaluate the effect of IV infusion of fat on (1) plasma CCK concentration and gallbladder volume and (2) CCK-induced gallbladder emptying. Intravenous infusion of Intralipid resulted in significant increases in serum triglycerides from 0.9 +/- 0.1 to 5.1 +/- 1.3 mmol/L (at 90 min). During fat infusion no significant changes in plasma CCK and gallbladder volume were noted when compared with basal values or to the control experiment. During IV fat, concomitant infusion of 0.25, 0.5, and 1.0 Ivy dog unit (IDU) per kilogram per hour of CCK-33 resulted in a significant reduction in gallbladder volume from 26 +/- 6 cm3 (basal) to 15 +/- 4 cm3 (p less than .05), 6 +/- 2 cm3 (p less than .05) and 2.5 +/- 1 cm3 (p less than .05), respectively. No significant differences in CCK-induced gallbladder emptying were observed between IV fat and saline infusion (control). It is concluded that, in contrast to intraduodenal fat, IV infusion of fat does not affect (1) basal plasma CCK and gallbladder volume and (2) CCK-induced gallbladder contraction.     

Differences in cholecystokinin release and gallbladder contraction between emulsified and nonemulsified long-chain triglycerides.

BACKGROUND: Fat is a potent stimulus of cholecystokinin (CCK) release. Apart from lipolysis, fatty acid chain length, and saturation, emulsification may also determine the magnitude of CCK release. METHODS: We have studied the effect of emulsification of soybean oil on CCK and pancreatic polypeptide (PP) release (radioimmunoassay [RIA]) and gallbladder motility (ultrasonography). Six healthy subjects were studied on three separate occasions in random order during (1) intraduodenal administration of emulsified long-chain triglycerides (LCT) (6 mmol/h for 120 minutes); (2) equimolar amounts of nonemulsified LCT with addition of emulsifier; and (3) saline with emulsifier (control). RESULTS: Intraduodenal administration of both nonemulsified LCT and emulsified LCT induced significant (p < .05) increases in plasma CCK and PP levels and reductions in gallbladder volume. However, compared with nonemulsified LCT, emulsified LCT resulted in a readier and significantly stronger CCK release (212+/-62 pmol/L per 120 minutes vs 36+/-7 pmol/L per 120 minutes; p < .05); PP release (2034+/-461 pmol/L per 120 minutes vs 671+/-106 pmol/L per 120 minutes; p < .05); and gallbladder contraction (77%+/-2% vs 41%+/-7%; p < .05). No significant alterations were observed in plasma CCK or PP levels and gallbladder volume during administration of saline with emulsifier. CONCLUSIONS: Intraduodenal administration of a low-dose emulsified LCT more potently stimulates CCK and PP release and gallbladder contraction in comparison to equimolar amounts of nonemulsified LCT. These findings point to an important role for solubilization of LCT in determining the magnitude of CCK release from the intestine.     

Physical state of meal affects gastric emptying, cholecystokinin release and satiety

To verify the influence of food consistency on satiety mechanisms we evaluated the effects of the same meal in solid-liquid (SM) and homogenized (HM) form on satiety sensation, gastric emptying rate and plasma cholecystokinin (CCK) concentration. Eight healthy men, aged 21-28 (mean 24.5) years were given two meals (cooked vegetables 250 g, cheese 35 g, croutons 50 g and olive oil 25 g, total energy 2573 kJ, with water 300 ml) differing only in physical state: SM and HM. The subjects consumed the meals in randomized order on non-consecutive days. The sensations of fullness, satiety and desire to eat were evaluated by means of a questionnaire, gastric emptying was assessed by ultrasonographic measurement of antral area, and plasma CCK concentration was measured by radioimmunoassay. The vegetable-rich meal was significantly more satiating (P < 0.05) when in the HM form than when eaten in a SM state. Furthermore, the overall gastric emptying time was significantly slowed (255 (SEM 11) min after HM v. 214 (SEM 12) min after SM; P < 0.05) and CCK peak occurred later (94 (SEM 12) min after HM v. 62 (SEM 11) min after SM; NS) when the food was consumed in the HM form. Independently of the type of meal, antral area was significantly related to fullness sensations (r2 0.46, P = 0.004). These results demonstrate that meal consistency is an important physical food characteristic which influences both gastric emptying rate and satiety sensation. Moreover, the relationship observed between antral area and fullness sensation confirms that antral distension plays a part in the regulation of eating behaviour.     

Low bioavailability of carbonyl iron in man: studies on iron fortification of wheat flour

The bioavailability in man of commercially available elemental iron powders is unknown despite their extensive use for fortification of flour. Carbonyl iron, which is widely used in Europe, is considered as one of the best reduced iron powders based on studies both in vitro and in animals. In this study, a 55Fe labeled carbonyl iron was prepared by neutron irradiation and used to fortify wheat flour. The native iron of the wheat was extrinsically labeled by 59FeCl3. Doubly labeled wheat rolls were served with different meals. The ratio of absorbed 55Fe/59Fe is a direct measure of the fraction of carbonyl iron that joins the nonheme iron pool and is made potentially available for absorption. This relative bioavailability of carbonyl iron was unexpectedly low and varied from 20 to 5% when the iron fortified wheat rolls were served with different meals. The baking process did not change the relative bioavailability nor the addition of ascorbic acid. The low and variable bioavailability of carbonyl iron in man, makes it necessary to reconsider the rationale of using elemental iron powders for the fortification of foods for human consumption.     

The soybean beta-conglycinin beta 51-63 fragment suppresses appetite by stimulating cholecystokinin release in rats

We previously demonstrated that soybean beta-conglycinin peptone suppresses food intake and gastric emptying by direct action on rat small intestinal mucosal cells to stimulate cholecystokinin (CCK) release. The aim of the present study was to define the active fragment in beta-conglycinin by using synthetic peptides chosen from the sequence of three beta-conglycinin subunits. We selected the fragments that had multiple nonadjacent arginine residues, and investigated their ability to bind to components of the rat intestinal brush border membrane as well as to stimulate CCK release and appetite suppression. The fragment from 51 to 63 of the beta subunit (beta 51-63) had the strongest binding activity. Intraduodenal infusion of beta 51-63 inhibited food intake and markedly increased portal CCK concentration. The threshold concentration of beta 51-63 to affect food intake was 3 micro mol/L. The CCK-A receptor antagonist abolished the beta 51-63-induced suppression of food intake. Three types of smaller fragments of beta 51-63 (beta 51-59, beta 53-63 and beta 53-59) and two types of fragments similar to beta 51-63 in the beta-conglycinin alpha and alpha' subunits (alpha 212-224 and alpha' 230-240) had less binding ability than did beta 51-63. Model peptides constructed with arginine (R) and glycine (G), such as GRGRGRG, had strong binding affinity, but peptides containing a single R or RR did not. These results indicate that the beta-conglycinin beta 51-63 fragment is the bioactive appetite suppressant in beta-conglycinin, and multiple arginine residues in the fragment may be involved in this effect.     

Incorporating dairy foods into low and high fat diets increases the postprandial cholecystokinin response in men and women

The postprandial period is a dynamic state of hormone and lipoprotein metabolism that can be influenced by dietary composition. The objective of this study was to determine whether the source of dietary fat [dairy (D) vs. nondairy (ND)] would modify the lipemic, insulin and cholecystokinin (CCK) response to high or low fat meals. Men and women (n = 24) consumed 4 test meals with a similar polyunsaturated:saturated (P:S; 0.12:1) fat ratio. The diets were high (38% energy) or low (20% energy) in fat, with or without fat from dairy sources. CCK responses were greater after consumption of meals containing D than ND, and for high compared with low fat meals. Women had higher CCK responses than men and were more sensitive to the differences in dietary treatments. Consumption of low fat meals resulted in greater insulin responses than high fat meals. However, after consumption of the low fat meals, the insulin response of D was about half of the ND response; no differences in insulin response were detected after the high fat meals. Triacylglyceride response was influenced primarily by the fat content of the diet. Consumption of dairy products containing fat was associated with an enhanced CCK response, which may have implications for the regulation of food intake. Blunting glucose and insulin response in low fat meals containing fat from dairy products may be useful for glycemic control.     

Amphetamine induced dopamine release increases anxiety in individuals recovered from anorexia nervosa

Objective:

Genetic, pharmacologic, and physiological data suggest that individuals with anorexia nervosa (AN) have altered striatal dopamine (DA) function.

Method:

We used an amphetamine challenge and positron emission tomography [¹¹C]raclopride paradigm to explore DA striatal transmission in 10 recovered (REC) AN compared with 9 control women (CW).

Results:

REC AN and CW were similar for baseline, postamphetamine [¹¹C]raclopride binding potential (BP_ND) and change (Δ) in BP_ND for all regions. In CW, ventral striatum Δ BP_ND was associated with euphoria (r = ?0.76; p = 0.03), which was not found for REC AN. Instead, REC AN showed a significant relationship between anxiety and Δ BP_ND in the precommissural dorsal caudate (r = ?0.62, p = 0.05).

Discussion:

REC AN have a positive association between endogenous DA release and anxiety in the dorsal caudate. This finding could explain why food‐related DA release produces anxiety in AN, whereas feeding is pleasurable in healthy participants. © 2011 by Wiley Periodicals, Inc. (Int J Eat Disord 2012)

     

Effect of different long-chain fatty acids on cholecystokinin release in vitro and energy intake in free-living healthy males

Long-chain fatty acids have been shown to suppress appetite and reduce energy intake (EI) by stimulating the release of gastrointestinal hormones such as cholecystokinin (CCK). The effect of NEFA acyl chain length on these parameters is not comprehensively understood. An in vitro screen tested the capacity of individual NEFA (C12 to C22) to trigger CCK release. There was a gradient in CCK release with increasing chain length. DHA (C22) stimulated significantly (P < 0.01) more CCK release than all other NEFA tested. Subsequently, we conducted a randomised, controlled, crossover intervention study using healthy males (n 18). The effects of no treatment (NT) and oral doses of emulsified DHA-rich (DHA) and oleic acid (OA)-rich oils were compared using 24 h EI as the primary endpoint. Participants reported significantly (P = 0.039) lower total daily EI (29 % reduction) with DHA compared to NT. There were no differences between DHA compared to OA and OA compared to NT. There was no between-treatment difference in the time to, or EI of, the first post-intervention eating occasion. It is concluded that NEFA stimulate CCK release in a chain length-dependent manner up to C22. These effects may be extended to the in vivo setting, as a DHA-based emulsion significantly reduced short-term EI.     

Effects of soya-bean protein and casein on serum cholesterol levels in rats

1. The effect of the soya-bean protein isolate and casein, both given 200 g/kg diet for 3-4 weeks, on serum cholesterol was compared in male rats. 2. Soya-bean protein exerted a hypocholesteramic effect only in a cholesterol-free low-fat (10 g maize oil/kg) diet, when the lowering action appeared independent of the strain of the rat or the feeding pattern. The results obtained with diets containing cholesterol or higher levels of fats or both showed no definite pattern of response. 3. Although the decrease in serum cholesterol appeared greater in alpha-lipoproteins than in beta-lipoproteins, the proportion of the former to total cholesterol remained almost unchanged. The concentration of serum apo A-I was significantly lower in rats given the vegetable protein. 4. Rats given soya-bean protein excreted significantly more neutral sterols. 5. The serum amino acid pattern did not reflect the difference in dietary protein. Addition of cholesterol to the diets modified the serum aminogarm, the decrease in threonine being most marked in both protein groups. 6. This study shows that the hypocholesteraemic action of soya-bean protein is easily modified by the type of diet.     

Effect of soya-bean protein on meat iron solubility and absorption in rats

1. Soya-bean proteins were used to replace 30 and 50% of the protein from 59Fe-labelled pigeon (Columba L.) and chicken meat, and the solubility of the meat 59Fe in vitro and its absorption in vivo in rats in the presence and absence of soya-bean proteins were measured. 2. Replacement of part of the chicken meat by soya-bean proteins reduced 59Fe solubility from chicken meat at all stages during simulated in vitro digestion. 3. 59Fe absorption from 59Fe-labelled chicken meat when given to both Fe-replete and Fe-deficient rats was reduced in the presence of soya-bean proteins but was unaffected by the presence of casein or bovine serum albumin. 59Fe-absorption from pigeon meat in the presence of soya-bean proteins was not reduced to the same extent as that from chicken meat. 4. There was no significant effect of soya-bean proteins on 59Fe-labelled haemoglobin Fe absorption in vivo in Fe-replete rats. 5. Absorption of 59Fe from the isolated haemoproteins from chicken meat was unaffected by soya-bean proteins but 59Fe absorption from the main non-haem-Fe fractions was strongly inhibited, particularly from haemosiderin.     

Exposure to inhalable flour dust in Canadian flour mills

In 1999, the American Conference of Governmental Industrial Hygienists (ACGIH(R)) proposed a Threshold Limit Value (TLV(R)) of 0.5 mg/m(3) for flour dust with a sensitization notation. The Labour Program of the Department of Human Resources Development Canada (HRDC), following notice of the intention to set a TLV, conducted a study of the levels of exposure to flour dust in flour mills across Canada to verify existing conditions, as well as to decide whether to adopt the proposed TLV or reference some other value. As part of the study, a relationship between flour dust concentrations obtained by using Institute of Occupational Medicine (IOM) samplers and closed-face 37-mm cassettes was examined and the literature on the health effects of exposure to flour dust was reviewed. A total of 104 millers, packers, sweepers, bakery mix operators, and others (mixed tasks) from 14 flour mills were sampled over an 8-hour work shift using IOM samplers. The results indicate that 101 employees (97.1%) were exposed to levels exceeding 0.5 mg/m(3), 66 employees (67.3%) to levels exceeding 5 mg/m(3), and 44 employees (42.3%) to levels exceeding 10 mg/m(3). For comparison purposes, flour dust measurements were also taken in a highly automated flour mill using state-of-the-art technology. The results suggest that even with the most up-to-date technology and proper cleaning operations in place, the flour milling industry may not be able to reduce the flour dust levels to below the TLV of 0.5 mg/m(3). According to the measurements of inhalable and total dust concentrations, the IOM sampler appears to be a more efficient collector of inhalable airborne particles up to 100 microm than the closed-face 37-mm cassette.     

Wheat aleurone flour increases cecal beta-glucuronidase activity and butyrate concentration and reduces colon adenoma burden in azoxymethane-treated rats

Processed wheat aleurone flour (WAF) is a source of insoluble fermentable dietary fiber that comes from the outer layers of the wheat kernel. A study was designed to evaluate WAF, wheat bran (WB) and alpha-cellulose as the source of dietary fiber (5 g/100 g of diet) in a semipurified high fat (20 g/100 g of as 1:1 lard/sunflower seed oil) diet fed to male Sprague-Dawley rats in which intestinal tumors were induced using azoxymethane (AOM). WAF at 33 g/100 g of diet (WAF33) and WB at 16 g/100 g of diet (WB16) increased the weight of feces and produced significantly higher concentrations in the cecum of the short-chain fatty acid butyrate (P < 0.001) than did no fiber (NF) and WAF added at only 10 g/100 g (1.5 g of dietary fiber) (WAF10). Cecal and fecal pH were both significantly lower in the WAF33 and WB16 treatments relative to control and no fiber treatments (P < 0.001). The intestinal tumors in the rats were assessed at 6 mo after the study began, and the WAF33- or WB16-fed rats showed a trend (P = 0.06) with 43% fewer colon adenomas relative to control. There was a significant inverse relationship between ss-glucuronidase activity and colon adenomas in the rat colon (r2 = 0.37, P = 0.001). WAF fiber influenced some metabolic markers of fermentation in the colon in a manner similar to that of WB, which, independent of the bulking effect, was associated with a trend to reduced colon adenomas. Significantly increased cecal ss-glucuronidase activity and/or butyrate concentrations may have protective influences in this context by mechanisms not yet fully elucidated.