FOR PROFESSIONAL USE ONLY

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1 The Role of Fibre in Diabetes! FOR PROFESSIONAL USE ONLY Accreditation Date: June 16, 2015 CCCEP File # I-P Expiry Date: June 9, 2018 CEUs 1.5 1

2 Disclosure This learning activity has received financial support from WN Pharmaceuticals in the form of program development fees. This learning activity has received in-kind support from WN Pharmaceuticals in the form of logistical support. Presenter Disclosure Presenter: Rishma Walji, ND, RAc, PhD I have the following relationships with commercial interests: Speaker/consulting fees: WN Pharmaceuticals Ltd. Speaking Fees for current program: I have received a speaker s fee from WN Pharmaceuticals Ltd. for this learning activity 2

3 Disclaimer For Professional Use Only This information is provided for educational purposes only and is not intended for self-diagnosis or self-treatment of a condition that should be interpreted by a qualified health care provider. While the information in this document has been carefully reviewed and reflects current clinical and scientific knowledge, it is subject to change. Introduction Fibre has been shown to promote good health and reduce the risk of chronic disease, such as heart disease, stroke, obesity, diabetes, and certain gastrointestinal disorders (Otles and Ozgoz, 2014). Although it is recommended that a healthy adult needs 21 to 38 grams of fibre per day, surveys show that the average daily Canadian intake is about 14 grams per day (Heart and Stroke, 2011; Health Canada 2012). Epidemiological studies suggest that higher levels of dietary fibre intake play a significant protective role in diabetes, independent of other dietary factors (Anderson et al., 2009). Data indicate that individuals with the highest intake of fibre have a 62% reduction in progression of pre-diabetes to diabetes over a 4-year period (Lindstrom 2006). 3

4 Introduction Epidemiological studies indicate it may be more significant to focus on an increased consumption of dietary fibre to prevent diabetes than glycemic index/load (Schulze, 2004; Meyer, 2000). Studies have found that soluble fibre has the potential to prevent and treat type 2 diabetes, and its complications, by aiding in body weight reduction, and improving insulin sensitivity, blood glucose, HbA1C, postprandial blood glucose levels, and serum lipid levels (Lee and Dugoua, 2011). Other research has demonstrated a strong inverse relationship between insoluble fibre and the risk of type 2 diabetes (Lattimer and Haub, 2010). Learning Objectives Goal: To educate pharmacists on the use of fibre in type 2 diabetes. Objectives: After completing this session, the pharmacist should be able to: Understand the differences between soluble and insoluble fibres. Describe the physiological activities of fibre in the body. Understand the role of different soluble fibres, namely Β-glucan, glucomannan, psyllium, guar gum and PolyGlycopleX, in the prevention and treatment of type 2 diabetes, and associated cardiometabolic changes. Explain the safety and efficacy of these fibres in type 2 diabetes. Be able to provide patients with practical tips to increase fibre consumption 4

5 Fibre: Definition and Classification A variety of definitions of dietary fibre exist worldwide, based on analytical methods for isolating dietary fibre or its physiological effects. Fibre is an indigestible non-starch polysaccharide In general, non-starch polysaccharides are divided into two groups (Otles and Ozgoz, 2014): Soluble Insoluble Most fibre-rich foods include approximately 1/3 soluble and 2/3 insoluble fibre (Lattimer and Haub, 2010). Soluble Fibre Viscous or fermentable fibres (Anderson et al., 2009). Dissolves in water forming viscous gels. Bypass the digestion of the small intestine and are easily fermented by the microflora of the large intestine. Binds with fatty acids. Prolongs stomach emptying and slows digestion of food. Found in some vegetables, fruit and legumes, such as dried beans and peas. Examples: beta-glucans, pectins, gums, mucilages, inulin-type fructans and some hemicelluloses. 5

6 Insoluble Fibre Not water soluble, and does not form a gel when mixed with liquid. Fermentation is limited in the colon. Moves bulk through the intestines. Controls and balances the ph in the intestines. Found in the skins of vegetables and fruit, and the bran portion of whole grains. Examples: lignin, cellulose, some pectins and some hemicelluloses. (Anderson et al 2009) Potential effects of dietary fibre consumption. Colonic fermentation with the production of short chain fatty acids (SCFA) can be observed with most types of dietary fibre to some extent, but it tends to be more pronounced with soluble dietary fibre in naturally available foods (Weickert and Pfeiffer, 2008). 6

7 Health Canada Claims Dietary Fibre (Health Canada, 2013): Improves laxation or regularity by increasing stool bulk. Reduces blood total and/or low-density lipoprotein cholesterol levels. Reduces post-prandial blood glucose and/or insulin levels. Provides energy-yielding metabolites through colonic fermentation. List of Dietary Fibres Reviewed & Accepted by Health Canada s Food Directorate Acacia gum (Gum Arabic) Barley bran Beta-glucan concentrate from oat or barley Corn bran Corn syrup (fibre) Fructooligosaccharides or oligofructose Galactooligosaccharides High amylose corn starch Inulin from chicory root, Jerusalem artichoke tuber or Blue agave head Isomaltooligosaccharides Maltodextrin (fibre) or resistant maltodextrin from corn, potato, tapioca, rice etc. Modified wheat starch Oat bran Oat hull fibre Partially hydrolyzed guar gum Pea hull fibre Polydextrose Polysaccharide complex (glucommannan, xanthan gum, sodium alginate) - PGX /PolyGlycoPlex Psyllium seed husk Sieved barley meal Soy cotyledon Sugar beet fibre Wheat flakes, starch-reduced Wheat bran Whole or edible parts (for example, flour, pulp, and peel) of traditional fruits, vegetables, cereals, legumes, nuts, seeds etc. (Health Canada, 2013) 7

8 Evidence of Fibre Benefits in Type 2 Diabetes Meta-analysis of 15 randomized studies (n= 484) published from January 1, 1980, to December 31, 2010, that involved an increase in dietary fibre intake as an intervention, and evaluated HbA1c and/or fasting blood glucose as an outcome (Post et al., 2012). Eleven trials were graded as high quality and four trials as moderate quality. The length of follow-up ranged from three to 12 weeks. Overall mean difference was a of fasting blood glucose by fibre of 0.85 mmol/l (95% CI, ) more than the reduction from placebo. Overall mean difference was a of HbA1c by fibre of 0.26% (95% CI, ) more than the reduction from placebo. These results suggest that increasing dietary fibre in the diet of patients with type 2 diabetes is beneficial and should be encouraged as a disease management strategy. Soluble Fibre in Diabetes High fibre diets in the prevention and treatment of diabetes relate to the viscosity of the fibre (National Research Council, 2001). The beneficial physiological effects of viscous fibres on blood glucose concentrations have been consistently demonstrated for over 25 years. Viscous fibres from food reduce glycemic response better than sources rich in non-viscous fibres (e.g., cellulose and lignin), and increase insulin sensitivity. Increased viscosity results in slower stomach emptying, slower rate of absorption, and changes in the composition of colonic microbial flora. 8

9 (Last and Wilson, 2006) Insoluble Fibre in Diabetes Several hypotheses explain the role of insoluble fibre in diabetes (Lattimer and Haub, 2010): 1. Accelerated secretion of glucose-dependent insulintropic polypeptide (GIP). GIP is an incretin hormone which stimulates postprandial insulin release. 2. Reduced appetite and food intake decreased caloric intake and BMI. 3. Production of short chain fatty acids via fermentation reduce postprandial glucose response. 9

10 Evidence of Fibre Benefits in Type 2 Diabetes Types of fibres which play a role in type 2 diabetes include: Β-Glucan Glucomannan Psyllium Guar gum PolyGlycopleX Note: The majority of studies examining fibre in diabetes look at cardiometabolic parameters, including glucose and insulin regulation, as well as lipid levels. Thus, the studies to be covered may touch on each of these factors. β-glucan About β-glucan Beta-glucans are highly viscous (at low concentrations), easily fermented, soluble fibres found naturally in oats, barley, mushrooms, fungi, bacteria, and algae (Linus Pauling Institute, 2012; Lattimer and Haub, 2010). β-glucans have been found to improve metabolic parameters of diabetes, such as hyperglycemia, hyperinsulinemia, hyperlipidemia and hypertension (Lee and Dugoua, 2012). 10

11 Mechanism of Action β-glucan Viscosity is the most probable mechanism in decreasing cholesterol and post prandial glucose metabolism (Lattimer and Haub, 2010). Leads to (Poppit et al., 2007): Slower rate of digestion in the intestinal lumen. Slower absorption of glucose into portal and systemic circulation. Reduced demand for insulin. β-glucan Evidence Four treatment cross-over trials, where subjects were randomized to (1) high-carbohydrate food control, (2) high carbohydrate food + fibre (10g of high barley β-glucan supplement), (3) high carbohydrate drink control and (4) high carbohydrate drink plus fibre (Poppit et al., 2007). Results: high β-glucan blunted the postprandial increases of blood glucose and insulin after the consumption of high-carbohydrate foods in 18 healthy men. 11

12 β-glucan Evidence continued A study involving 10 healthy university students found the amount of extractable b-glucan had a high correlation between the glycemic and insulinemic response (Mӓkelӓinen et al., 2007): 2 g of β-glucan GI by 7 U/1 g of β-glucan 4 g of β-glucan GI by 10.5 U/1 g of β-glucan 6 g of β-glucan GI by 5 U/1 g of β-glucan Glycemic response curves to four oat products and glucose load (mean values). Insulin response curves to four oat products and glucose load (mean values). (Mӓkelӓinen et al., 2007) 12

13 Evidence continued β-glucan In an 8-week single blind, controlled study (n=89), 5 g of β-glucan from oats significantly lowered total-cholesterol by 7.4% (P<0.01) and LDL-C by 6.7% (P<0.01), and postprandial concentrations of glucose (30 min, P=0.005) and insulin (30 min, P=0.025) (Biorklund et al., 2005). At baseline, all were hypercholesterolaemic subjects. The beverage with 10 g of β-glucans from barley did not affect serum lipids significantly in comparison with control. No statistically significant effects compared to control of the beverages with barley β-glucans were found. Evidence continued β-glucan In the treatment of diabetes, β-glucan has been found to improve glucose, insulin and cholesterol levels in those diagnosed with type 2 diabetes (Chen et al., 2008). Significant decrease in postprandial glucose and insulin levels in type 2 diabetics who consumed single doses of 4, 6 or 8.4 g of β-glucan (Tappy, 1995c). In a DBRCT - Consumption of β-glucan-enriched (3 g β-glucan daily) bread by patients with type 2 diabetes and increased low density lipoprotein cholesterol (LDL-C) levels (>3.37 mmol/l), led to significantly reduced LDL-C, total cholesterol and insulin resistance after just three weeks of consumption (Liatis et al., 2009). 13

14 β-glucan Evidence continued Review of 34 human trials investigating the post-prandial blood-glucose lowering ability of oat and barley food products (Tosh, 2013): Meals with g oat or barley β-glucan glycemic response by an average of 48±33 mmol min/l compared to a suitable control. Change in glycemic response was greater for intact grains vs. processed foods. β-glucan Evidence continued (Tosh, 2013 cont d) For processed foods: Glycemic response was more strongly related to β-glucan dose alone (r 2 =0.48, P<0.0001) than to the ratio of β-glucan to available carbohydrate (r 2 =0.25, P<0.0001). For processed foods containing 4 g of β-glucan, the linear model predicted glycemic response of 27±3 mmol min/l, and 76% of treatments significantly glycemic response. Intact grains and a variety of processed oat and barley foods with at least 4 g of β-glucan and g available carbohydrate can significantly post-prandial blood glucose. 14

15 Evidence continued β-glucan Inconsistency between studies exists due to molecular weight and solubility of β-glucan (Lattimer and Haub, 2010). Molecular weight can be changed by food processing and the source of the β-glucan. Dosage (adults) Range from 3-10 g daily to improve metabolic parameters (Lee and Dugoua, 2011). Glucomannan About Glucomannan Glucomannan is a highly-viscous water soluble polysaccharide fibre extracted from plants and widely used in Japan and Taiwan as a dietary staple (Lee and Dugoua, 2012). Found to be beneficial in lowering blood glucose and blood cholesterol levels in patients with type 2 diabetes (Lee and Dugoua, 2012). 15

16 Glucomannan Health Canada Claims (Health Canada, 2010): Helps to lower cholesterol levels (by reducing cholesterol absorption from the gastrointestinal tract). (Used in Herbal Medicine as a): bulk-forming laxative. promote(s) bowel movements by increasing bulk volume and water content. provide(s) gentle relief of constipation and/or irregularity. Glucommanan Mechanism of Action (Sood et al., 2008) Prolongs gastric emptying increased satiety, reduced body weight, decreased ingestion of foods that increase cholesterol and glucose concentrations. Reduces postprandial rise in plasma glucose. Suppresses hepatic cholesterol synthesis. Increases fecal elimination of cholesterol-containing bile acids. Modulates the hormones ghrelin and leptin, responsible for stimulating and suppressing appetite. Addition of 1 g of glucomannan 30 min prior to an oral glucose tolerance test suppressed the rise of prandial ghrelin, the hormone responsible for increasing appetite (Chearskul et al., 2009). 16

17 Evidence Glucomannan Randomized double-blind crossover-trial over 28 days evaluated the effect of 3.6 g daily of Konjac-plant glucomannan on patients (n=22) with type 2 diabetes (glucose mmol/l) and elevated cholesterol, not currently on cholesterol medication (Chen et al., 2003). plasma cholesterol (11.1%, p = ) LDL-cholesterol (20.7%, p = ) total/hdl cholesterol ratio (15.6%, p = ) ApoB (12.9%, p = ) fasting glucose (23.2%, p = 0.002) Plasma triglyceride, HDL-cholesterol, LDL/HDL cholesterol, postprandial glucose and body weight were not significant after adjustment. Fecal neutral sterol and bile acid concentrations were increased by 18.0% (p = 0.004) and 75.4% (p < 0.001), respectively Evidence Glucomannan Meta-analysis of 14 randomized controlled trials (n=531) of glucomannan appeared to statistically significantly lower total cholesterol, LDL cholesterol, triglycerides, body weight and fasting blood glucose (P = 0.04) (Sood et al., 2008). Total cholesterol: mg/dl LDL cholesterol: mg/dl Triglycerides: mg/dl Body weight: kg Fasting blood glucose: mg/dl Glucomannan effects of lowering LDL-C was also observed in a randomized crossover study that found glucomannan alone (10 g/day) significantly lowered LDL-C in both healthy subjects and type 2 diabetes subjects (Yoshida et al., 2006). 17

18 Glucomannan Dosage (adults) 3-10 g daily appears to lower glucose/ldl (Lee and Dugoua, 2011). About Psyllium Psyllium Psyllium, is a viscous, soluble fibre isolated from psyllium seed husks, found in laxatives, ready-to-eat cereals, and Natural Health Products (Linus Pauling Institute, 2012). From the plant Plantago ovatum and contains at least 67% soluble fibre (Lee and Dugoua, 2012). Psyllium has advantages over other types of soluble fibre: Less readily fermented less abdominal bloating and flatulence, and better tolerated (Pal and Radavelli-Bagatini, 2012). 18

19 Psyllium About Psyllium continued Psyllium has been shown to be an effective supplement in the control of body weight and body composition, cholesterol, triglycerides, glucose and insulin levels both in animal and human studies (Pal and Radavelli-Bagatini, 2012). Effective supplement, in combination with dietary intervention, for the prevention and treatment of type 2 diabetes and its cardiovascular complications (Lee and Dugoua, 2012; Pal and Radavelli-Bagatini, 2012). Psyllium Health Canada Claims (Health Canada, 2011): Psyllium fibre helps reduce/lower cholesterol. Psyllium fibre helps reduce/lower (LDL) cholesterol, a risk factor for heart disease. 19

20 Psyllium Mechanism of Action (Pal and Radavelli-Bagatini, 2012) Psyllium modulates glucose levels via: Formation of a viscous gel in aqueous solution slowed access of glucose to the small intestine s absorptive epithelium, thereby blunting postprandial glucose peaks. Delayed gastric emptying slowed carbohydrate uptake. Sequestration of carbohydrates ingested with the meal, retarding carbohydrate access to digestive enzymes. Evidence Psyllium Randomized, single-blind, parallel-design study of overweight/obese individuals over a 12-week period (n=52) showed participants consuming a high-fibre diet (psyllium supplement plus fibre from a healthy diet) provided the greatest improvements in metabolic syndrome risk factors. Significant decrease in insulin levels, vs control group at 6 (-8%; P= 0 02) and 12 weeks (-31%; P<0 001) of intervention. However, glucose levels were not significantly different between the groups at 12 weeks (Pal et al., 2011). In a DBPC trial on 49 patients, 5.1 g psyllium twice daily, taken 30 min before meals, given to type 2 diabetic patients in addition to drug and dietary treatments significantly reduced fasting blood glucose, HbA1C, and LDL/HDL-C levels and significantly increased HDL-C levels (p<0.05) (Ziai et al., 2005). 20

21 Psyllium Evidence continued Meta-analysis, 21 studies n=1717 (Wei, 2009) Compared with placebo, consumption of psyllium lowered serum total cholesterol by mmol/l (95% CI), and LDL cholesterol by mmol/l (95% CI). There was a time effect of psyllium on total cholesterol and on LDL cholesterol suggesting that psyllium reduced serum total cholesterol more quickly than LDL cholesterol. Psyllium Dosage (adults) grams daily, for reduced glucose levels in a period of 6-8 weeks. ~21-23 grams daily, for reduced plasma insulin levels (Pal and Radavelli-Bagatini, 2012). 21

22 Guar Gum About Guar Gum Guar gum, a galactomannan gum extracted from the endosperm of the Guar bean, is mainly found in India and Pakistan (Lee and Dugoua, 2012). Contains 75% soluble fibre (Lee and Dugoua, 2012), and 7.6% insoluble fibre (Butt et al., 2007). Shown to reduce plasma glucose levels, as well as improve lipid profiles (Dall Alba et al., 2013). Guar Gum Mechanism of Action Can blunt the postprandial increase in glucose and insulin, resulting in HbA1c decrease by (Dall Alba et al., 2013): Increasing the viscosity of gut contents. Reducing glucose diffusion through the unstirred water layer and the accessibility of a-amylase to its substrates. Decreasing pancreatic enzyme activities. 22

23 Guar Gum Evidence Randomized, open-label, parallel, controlled clinical trial study conducted in patients with type 2 diabetes and metabolic syndrome (n=44). All patients followed their usual diet and the intervention group (n=23) received 10g/d of partially hydrolysed guar gum. Evaluated at baseline, 4 and 6 weeks (Dall Alba et al., 2013). Guar Gum Evidence continued (Dall Alba et al., 2013 cont d). Results Baseline 4 Weeks 6 Weeks HbA1C (%) Waist circumference(cm) hr urinary albumin excretion (mg) Trans-FA (mg/l) Blood pressure, TAG, HDL-cholesterol, fasting plasma glucose, total and LDLcholesterol, C-reactive protein and endothelin-1 did not change in either group. P value: <

24 Evidence continued Guar Gum The addition of guar gum to the diet can decrease LDL-C by 10-15% and the addition of guar flour can reduce the postprandial rise in glucose and insulin by 26.5% (Butt et al., 2007). In one randomized trial (n=11), guar gum ingestion lead to (Russo et al., 2003): gastric emptying time. blood glucose and insulin levels. blood pressure. Guar Gum Dosage (adults) 8-15 g (Lee and Dugoua, 2012). 24

25 PolyGlycopleX About PolyGlycopleX PolyGlycopleX (a-d-glucurono-a-d-manno-ß-d-manno-ß-d-gluco, a-l-gulurono-ß-d mannurono, and ß-D-gluco-ß-D-mannan) is a novel natural polysaccharide (fibre) combined in a proprietary way. Researchers have found that combining three viscous polysaccharides creates a novel polysaccharide that has a higher viscosity than any currently known individual polysaccharide or fibre blend. The viscosity of PolyGlycopleX is greater than expected relative to its constituents. This very high viscosity level means that far less needs to be consumed and its delayed viscosity (developing over 15 to 30 minutes) renders its incorporation into foods and beverages easier and more palatable. Viscosity of PolyGlycoPlex (PGX) 25

26 Evidence PolyGlycopleX One study investigated the impact of PolyGlycopleX on the glycemic index when added to liquid (glucose) and solid (white bread plus margarine) high-carbohydrate food formulations (Jenkins et al., 2010a). Three different doses, 2.5, 5, and 7.5 g, were administered with each food or beverage and the glycemic index calculated for each dose. The results for the glucose drink showed that 2.5, 5, and 7.5 g of PolyGlycopleX reduced the GI by 16.3, 22.3, and 27.5% respectively. The results for the white bread plus margarine showed that 2.5, 5, and 7.5 g of PolyGlycopleX reduced the GI by 28.9, 44.2, and 49.2% respectively. Evidence continued PolyGlycoPlex In another experiment, the effect of PolyGlycopleX on the glycemic index was investigated when it was added to commonly consumed foods with various GIs (Jenkins et al., 2010b). The glycemic index was determined for cornflakes with milk, rice, turkey dinner, and yogurt, with or without 5 g of PolyGlycopleX sprinkled onto the foods. The addition of PolyGlycopleX to cornflakes, rice, turkey dinner, and yogurt resulted in a 26, 45, 24, and 9% reduction in GI, respectively. (significant in all except turkey and yogurt) PolyGlycopleX incorporated into a baked granola reduced its GI by 45 and 64%, with the use of 2.5 g and 5 g of PolyGlycopleX, respectively. 26

27 The effect of PolyGlycopleX on the Glycemic Index (Jenkins et al., 2010b) Evidence continued PolyGlycopleX The glycemic effect of adding PolyGlycopleX to water and consuming it alongside starchy foods (white bread, white rice, boiled potatoes, French fries, cornflakes and instant oatmeal/porridge) was investigated (Brand-Miller et al., 2011). On average, a dose of 2.5 g reduced the GI by 16 22% depending on the food and a dose of 5 g reduced the GI by 28 35% depending on the food. 27

28 PolyGlycopleX Evidence continued Studies conducted on PolyGlycopleX reduced the risk factors associated with metabolic syndrome by: 1. Reducing waist circumference and most likely reducing intra-abdominal fat (Lyon et al., 2010, Reichert et al., 2013a). 2. Lowering postprandial blood sugar levels (Jenkins et al., 2010a, Jenkins et al., 2010b, Brand-Miller et al., 2011). 3. Lowering cholesterol (Carabin et al., 2009, Lyon et al., 2010, Reichert et al., 2013b). 4. Lowering insulin levels and improving insulin sensitivity (Grover et al., 2011, Lyon et al., 2010). Evidence continued PolyGlycopleX One study examined the effects of PolyGlycopleX on various risk factors associated with metabolic syndrome in adults with abdominal obesity n=64 (Reimer et al., 2013). Daily ingestion of 15 g of PolyGlycopleX over 14 weeks was associated with a significant reduction in total and LDL cholesterol, improvements in glucose tolerance, and a reduction in inflammatory cytokines (resistin and interleukin-6) compared to rice flour placebo. Waist circumference and visceral fat were reduced to a greater extent with PolyGlycopleX than with placebo. Conclusion: PolyGlycopleX supplementation is effective in reducing risk factors related to metabolic syndrome in adults with abdominal obesity. 28

29 PolyGlycopleX Dosage (adults) Start with 1-2 softgels of PolyGlycopleX Daily or 2.5 grams of PolyGlycopleX granules at one meal. Gradually add PolyGlycopleX to more meals every 2-3 days. It is important to drink at least 250 ml (8 fl oz) of water per 2.5 gram serving. (Grover, 2011; Jenkins, 2010; Murray 2015) Safety and Adverse Effects Dietary Fibre (Linus Pauling Institute, 2012): Abdominal cramping, bloating, or gas may occur with rapid increase in dietary fibre intake. Symptoms can be diminished by increasing fluid intake to approximately 64 oz/day (~2 liters/day). Rare reports of intestinal obstruction due to large intakes of oat bran or wheat bran, usually in those with impaired intestinal motility or difficulty chewing. 29

30 Safety and Adverse Effects Isolated Fibres and Fibre Supplements Fibres such as guar gum, inulin and oligofructose, fructooligosaccharides, polydextrose, resistant starch, and psyllium have been found to cause abdominal cramping, bloating, gas, and diarrhea (Linus Pauling Institute, 2012). Glucomannan: Generally well tolerated, adverse gastrointestinal effects such as loose stools, flatulence, diarrhea, and abdominal discomfort are the most commonly reported (Sood et al., 2008). Concern regarding choking hazard with glucommanan has arisen when taken with insufficient water or in individuals with difficulty swallowing (Health Canada, 2010). Tablets may also pose more risk than capsules or powdered forms. Safety and Adverse Effects Isolated Fibres and Fibre Supplements (Linus Pauling Institute, 2012): Guar Gum: Guar gum-containing supplement for weight loss has been associated with esophageal and small bowel obstruction. Psyllium: Cases of intestinal obstruction by psyllium have been reported when taken with insufficient fluids or by people with impaired swallowing or gastrointestinal motility. 30

31 Drug Interactions Psyllium may reduce the absorption of lithium, carbamazepine, digoxin, and warfarin when taken at the same time (Linus Pauling Institute, 2012). Guar gum may slow the absorption of digoxin, acetaminophen, and bumetanide and decrease the absorption of metformin, penicillin, and some formulations of glyburide when taken at the same time (Linus Pauling Institute, 2012). All fibres may be additive to glucose lowering medications, requiring adjustment to medication regimes. In general, medications should be taken at least one hour before or two hours after fibre supplements, as fibre may inhibit or alter drug absorption (Linus Pauling Institute, 2012). Nutrient Interactions Some fibres from fruits and vegetables that have cation exchange capacity from unmethylated galacturonic acid residues and phytic acid from cereal fibres, have been shown to reduce the absorption and retention of several minerals such as iron, zinc, calcium and magnesium (Linus Pauling Institute, 2012; Otles & Ozgoz, 2014). Highly fermentable fibres have shown improved metabolic absorption of certain minerals, such as calcium, magnesium and iron, even with phytic acid present at low levels (Otles & Ozgoz, 2014). Examples of highly fermentable fibres include pectin, various gums, resistant starches, cellulose, certain oligosaccharides like soy and fructooligosaccharides, inulin, lactulose and related sugars. 31

32 Ways to Increase Daily Fibre Intake Results of controlled clinical trials support recommendations that people with diabetes aim for high-fibre intakes by increasing consumption of whole grains, legumes, nuts, fruits, and nonstarchy vegetables (Linus Pauling Institute, 2012). Current recommendations for dietary fibre intake are related to age, gender, and energy intake (Anderson et al., 2009; Otles & Ozgoz, 2014). The general recommendation for adequate intake (AI) is 14 g/1000kcal (Otles & Ozgoz, 2014): Women: 2000 kcal/day 28 g/day Men: 2600 kcal/day 36 g/day Canadian Diabetes Association recommends grams of fibre each day. Ways to Increase Daily Fibre Intake Soluble food sources: oat/oat bran, dried beans and peas, nuts, barley, flax seed and psyllium husk, fruits such as oranges and apples, vegetables such as carrots. Insoluble food sources: vegetables, fruit and root vegetable skins, whole-wheat products, wheat oat, corn bran, seeds & nuts. From the Canadian Diabetes Association (Canadian Diabetes Association, 2014; Health Canada 2013): Good foods with at least 2 grams of fibre per serving can claim to be a source of fibre. Better foods with at least 4 grams of fibre per serving can claim to be a good source of fibre. Best foods with at least 6 grams of fibre per serving can claim to be a very good or excellent source of fibre. 32

33 Ways to Increase Daily Fibre Intake Eat at least five servings of fruits and vegetables daily. Choose whole grain bread, pasta, cereal, crackers and rice. Eat oatmeal, whole-grain cereal, or bran cereal for breakfast. Eat the skin and seeds of vegetables and fruit. Use whole grain flour in your homemade baked goods. (Canadian Diabetes Association, 2014) Ways to Increase Daily Fibre Intake cont d Add barley, beans and lentils to soups and salads. Replace meat with beans, split peas and lentils, a few times per week. Add ground flax seeds or chia seeds to yogurt, cereal or homemade baked goods. Add a small handful of almonds or other nuts to a salad. When dietary intake is insufficient, using fibre supplements may be a suitable addition in order to meet the daily recommendation. (Canadian Diabetes Association, 2014) 33

34 Practical Considerations for the Pharmacist Individuals who consume significant amounts of dietary fibre, compared to those who have minimal intake, are at a lower risk for developing cardiovascular disease, diabetes, hypertension, obesity, cancer, and certain gastrointestinal diseases (Otles & Ozgoz, 2014; Lindstrom 2006; Pal 2011). Increased viscosity results in slower stomach emptying, slower rate of absorption, and changes in the composition of colonic microbial flora (National Research Council, 2001). Practical Considerations for the Pharmacist Due to the recognized beneficial effects of dietary fibre intake in people with diabetes, higher intakes than those recommended for the general population [25 g and 38 g for women and men, and 21 g and 30 g for women and men over 51 years, respectively] are recommended for adults with diabetes (25 to 50 g/day or 15 to 25 g per 1000 kcal) Canadian Diabetes Association, clinical practice guidelines 34