Carbohydrates, fiber and resistant starch in white potatoes links to health outcomes

Transcription

1 Carbohydrates, fiber and resistant starch in white potatoes links to health outcomes Joanne Slavin Professor Department of Food Science and Nutrition University of Minnesota October 14, 2014 My food journey and disclosures Grew up and worked on a dairy farm in Wisconsin which I still own with my 2 sisters 2014 crops include pumpkins, soybeans, and corn, no potatoes Started as a dietitian; got PhD in Nutrition at UW Madison 6 years as Extension Nutritionist at U of MN Teach Life Cycle Nutrition and Human Nutrition 30+ years of research in dietary fiber, whole grains, phytochemicals, and everything else Member of 2010 Dietary Guidelines Advisory Committee (DGAC) Serve on Scientific Advisory Council for APRE Alliance for Potato Research and Education 100% Irish From the Science to Me Nutrient Adequacy Meet nutrient needs without exceeding calorie needs Dietary Reference Intakes (DRIs) Acceptable Macronutrient Distribution Ranges (AMDR) Protein: 10 35% of kcal Carbohydrates: 45 65% of kcal Fat: 20 35% of kcal Recommended Dietary Allowance (RDA) Adequate Intake (AI) Tolerable Upper Level Intake (UL) The Science Policy Me 1

2 Food advice: Evolution of USDA s Food Guidance Moderation and Variety 1950s-1960s 1970s s Food for Young Children Carbohydrates in the Diet Vegetables, fruits, grains, legumes, and milk are main food sources of carbohydrates Grains and certain vegetables (potatoes, corn) high in starch (glucose) except sweet potatoes (sucrose) Fruits and green vegetables contain little starch fruits mostly sugar Apples and pears high in fructose (66%), most other fruits 50/50 glucose/fructose (sucrose); milk 50/50 glucose/galactose Does a carbohydrate equal a carbohydrate No Chemical structure mono, di, polysaccharide Digestible vs. non digestible Speed of digestion and absorption Glycemic index Fermentable vs. non fermentable Physical structure in solution, part of a food, associated substances (protein), part of a seed or grain, particle size Fiber agreement Marker of a healthy diet whole grains, fruits, vegetables, legumes Concept carbohydrates and lignin that escape digestion in the upper GI tract but may be fermented in the gut Nutrient according to 2002 Dietary Reference Intakes (DRIs) Regulated On the Nutrition Facts panel 25 g Daily Value (DV), may increase to 28 g DV 2

3 Dietary fiber intake is low Typical fiber intake in US is 15 grams per day recommended levels are g/day Most fiber containing foods 1 3 g of fiber Apple 2 grams Lettuce 1 gram WW bread 2 grams Oatmeal 3 grams White flour and white potatoes provide the most fiber in the US diet, not because they are concentrated fiber sources, but because they are widely consumed Slavin. Health implications of dietary fiber. J Am Diet Assoc 2008;108:1716. What is resistant starch? Starch digested in the small intestine Resistant Starch Fiber fermented in the large intestine First Official Definition (1992) starch or starch degradation products not absorbed in the small intestine of healthy people. Current Intake of Resistant Starch Relative Risk of Death From CHD Current Intake Resistant Starch Average in U.S.: 4.8g/day 1 Range in U.S.: g/day 1 Worldwide: 3 10g/day 2 1. Murphy M, Douglass JS, Birkett A. Resistant starch intake in the United States. J Am Diet Assoc. 2008;108: Baghurst PA, Baghurst KI, Record SJ. Dietary fibre, non-starch polysaccharides and resistant starch: a review. Supplement to Food Australia 1996;48(3):S3-S35. 3

4 Gut microbiota influence metabolism & body composition Glycemic index Rating of carbohydrate containing foods according to their effect on blood glucose levels. It compares 50 g of available carbohydrate from the test food with 50 g of carbohydrate from a reference, typically glucose Vrieze et al, Diabetologia (2010) 53: Glycemic index values a No official database Fructose 15 Sucrose 65 Glucose 103 Boiled potatoes French fries Boiled sweet potatoes apple Banana Potato GI Varies from Low to High with Variety and Preparation Variety GI Preparation Carisma 53 Boiled 8 minutes Marfona 56 Boiled 15 minutes Charlotte 66 Boiled 15 minutes Russet Burbank 72 Baked whole, cooled, reheated Russet Burbank 98 Microwaved 18 min Pontica 79 Microwaved whole, 7 min Pontica 93 Baked whole a. Values obtained from 1. Atkinson. Diabetes Care, 2008; 31: Foster-Powell. Am J Clin Nutr 1995;62:8715. Cooking gelatinizes potato starch and enhances digestion 4

5 Hierarchy of Evidence Stronger Evidence Carbohydrates and Health Outcome Questions in 2010 Dietary Guidelines Advisory Committee (DGAC) Weaker Evidence RCT Double Blinded Intervention study Prospective, cohort study Clinical trial Cross sectional study Case Report Expert Opinion What is the relationship between glycemic index or glycemic load and body weight, type 2 diabetes, cardiovascular disease, and cancer? What is the relationship between glycemic index or glycemic load and body weight, type 2 diabetes, cardiovascular disease, and cancer? Strong and consistent evidence shows that glycemic index and/or glycemic load are not associated with body weight and do not lead to greater weight loss or better weight maintenance Abundant, strong epidemiological evidence demonstrates that there is no association between glycemic index or load and cancer What is the relationship between glycemic index or glycemic load and body weight, type 2 diabetes, cardiovascular disease, and cancer? A moderate body of inconsistent evidence supports a relationship between high glycemic index and type 2 diabetes Strong, convincing evidence shows little association between glycemic load and type 2 diabetes Due to limited evidence, no conclusion can be drawn to assess the relationship between either glycemic index or load and cardiovascular disease 5

6 GI/GL and T2 diabetes in 8 European Countries GI and GL were not associated with incident diabetes An expansion of the GI tables and systematic GI value assignment to foods may be needed to improve the validity of GI values derived in such studies Digestible carbohydrate intake is not associated with diabetes risk and suggests that diabetes risk with high GI and GL diets may be more modest than initial studies suggested Sluoijs I et al. J Nutr 2013;143: DF and GI for Nordic Nutrition Recommendations DF is associated with decreased risk of chronic diseases and metabolic conditions There is not enough evidence that choosing foods with low GI will decrease the risk of chronic diseases in the population overall Suggestive evidence that ranking food based on GI might be of use for overweight and obese individuals Issues regarding methodology, validity and practicality of the GI remain to be clarified Overby NC et al. Food and Nutrition Research :20709 DGAC Carbohydrate Chapter Summary or the good carbohydrate Healthy diets are high in carbohydrate. AMDR for carbohydrates are 45 65%. A maximum intake of 25% of added sugars is suggested. Americans should choose fiber rich foods such as whole grains, vegetables, fruits, and cooked dry beans and peas as staples in the diet. Dairy products are also a nutrient dense source of carbohydrates. Carbohydrates are the primary energy source for active people. Sedentary people, including most Americans, should decrease consumption of caloric carbohydrates to balance energy needs and attain and maintain ideal weight. Dietary Guidelines for Americans

7 Ch 4: Foods and Nutrients to Increase Comparison of Consumption to Recommendations LTM2 Potatoes & Health: Macronutrients Protein: 1-1.5% by weight High biological value: (Egg:100) High in lysine Lipid: 1.2% by weight Carbohydrate: Amylopectin: high amylopectin/amylose (3:1) contributes to high glycemic response Fiber: 1-2% by weight Dietary Fiber and Potassium in Common Fruits and Vegetables NLEA Servings Dietary Fiber g Potassium mg Potato, boiled Iceberg lettuce Tomato Carrot Sweet corn Banana Apple with skin Orange Green grapes

8 Slide 28 LTM2 Frances - I will fill in this this slide and sort by fiber per 100 grams if you agree with the format. I included top consumed fruits/veg and only one example of potatoes to be consistent. Liz Marr, 10/16/2011

9 The role of potatoes and potato components in cardiometabolic health: A review Potatoes contribute key nutrients to the diet, including vitamin C, potassium, and dietary fiber Potatoes and potato components have a favorable impact on several measure of cardiometabolic health Blood pressure Blood lipids Inflammation Body weight Controlled clinical trials are needed to define the impact of potatoes on cardiometabolic health McGill et al. Ann Med 2013;45: Changes in diet and lifestyle and long term weight gain in women and men Prospective study of 3 cohorts 120,877 US women and men Within each 4 year period, participants gained an average of 3.35 lbs. 4 year weight change was most strongly associated with intake of potato chips (1.69 lb), potatoes (1.28 lb), SSBs (1.00 lb), unprocessed red meats (0.95 lb), processed meats (0.93 lb) Specific dietary and lifestyle factors are independently associated with longer term weight gain Mozaffarian et al. New Eng J Med 2011;364: White Potato Consumption and Nutrient Intake in Children & Adolescents, Freedman MR and DR Keast, Nutr Res 31 (2011) 270. Based on NHANES Data, n=7332 Whole potato, french fries, or % Children/Adolescents oven-baked fries Energy, % total 9-12% Fat, % total 8-15% >10% of total intakes Fiber, B6, Potassium >5% of total intakes Thiamin, niacin, vitamins C & K, P, Mg, Cu Potatoes, including French Fries, provide shortfall nutrients within energy requirements for children and adolescents. Income and race/ethnicity influence dietary fiber (DF) intake and vegetable consumption NHANES mean intake of DF across sex, age, raceethnicity, family income, and poverty threshold. DF intakes low; children 14 g/d, adults 17 g/d Lower family income and living at less than 131% of poverty were associated with lower DF intakes among adults Total vegetable consumption is lower than recommended and including white potatoes has declined Government policies that single out and discourage consumption of white potatoes, especially among low income individuals who receive food assistance, may lead to unintended consequences of further decreasing intake of dietary fiber Storey & Anderson. Nutr Res 8

10 Vegetable cost metric show that potatoes and beans provide most nutrients per penny Estimated cost impact of meeting the USDA requirements using 2008 national prices for 98 vegetables, fresh, frozen, and canned Calculated per 100 grams, per 100 calories, and per edible cup Beans and starchy vegetables, including white potatoes were cheaper/100 calories than were dark green and deep yellow vegetables. For the more frequently consumed vegetables, potatoes and beans were the lowest cost sources of potassium and fiber. Drewnowski & Rehm. PLoS ONE 8(5): e63277.doi: /journal.pone Choices made by low income women provided with an economic supplement for fresh fruit and vegetable purchase Investigated whether providing supplemental financial support specifically for purchase of fresh fruits and vegetables would result in high uptake of the supplement, and what the individuals would choose to purchase. 602 women enrolled at 3 WIC sites in LA were recruited 90% use of vouchers 10 most frequently mentioned items were oranges, apples bananas, peaches, grapes, tomatoes, carrots, lettuce, broccoli, and potatoes. Low income women used the supplement and purchased a wide variety of fresh fruits and vegetables. Herman et al. J Am Diet Assoc 2006:106: Conclusions Consumption of a wide variety of vegetables will ensure adequate intake of dietary fiber, vitamins, and minerals Food costs, food availability, convenience, food traditions, and taste are key issues in food choice Arbitrary decisions, such as not allowing white potatoes in government programs, have unintended consequences of reduced intakes of dietary fiber and potassium, 2 nutrients of concern Solving important nutrition problems will require strong science and partnerships based on trust among academics, the government, commodity groups, activists, and food companies 9