Pasta, Low Glycemic Index Diets and Health Dr. Cyril W.C. Kendall Department of Nutritional...

Pasta, Low Glycemic Index Diets and Health

Dr. Cyril W.C. Kendall

Department of Nutritional Sciences, Faculty of Medicine, University of Toronto;

The Clinical Nutrition & Risk Factor Modification Center, St. Michael’s Hospital;

Toronto, OntarioCANADA

Weight Loss & Dieting

• 45% of women and 30% of men are

trying to lose weight (US data).

Christine Wood, M.D. How to Get Kids to Eat Great & Love It

Desire for Healthy Eating

• What parents want for their children:– 99% of parents agreed that “it is important for

my child to eat nutritious foods”;– 91% believed that it’s important to “restrict the

amount of sugars consumed”; and– 84% believed “dietary fat reduction was

important”

Obesity Trends* Among U.S. AdultsBRFSS, 1985

Source: Mokdad A H, et al. J Am Med Assoc 1999;282:16, 2001;286:10.

Childhood Overweight and Obesity: International Statistics

(Ebbeling et al, Lancet, 2002)

Health Consequences of Obesity

(Ebbeling et al. Lancet, 2002)

Diet (Macronutrient Intake) Trends

http://images.amazon.com/images/P/0471705284.01.LZZZZZZZ.jpg

http://www.amazon.com/exec/obidos/ASIN/0312315228/lowcarbcanad/

http://www.amazon.com/exec/obidos/ASIN/0312251890/lowcarbcanad/

Nutrient Composition of Various Diets

Nutrient Composition of 1600 kcal Diets

Atkins Protein Sugar The ADA High Pritikin OrnishPower Busters Zone Fiber

CHO (%) 5 8 40 40 60 63 73 74

Protein (%) 35 35 28 28 20 16 18 18

Fat (%) 59 53 32 32 20 21 9 7

SFA (%) 22 15 8 7 6 4 2 1

Cholesterol (mg/d) 924 657 280 264 112 58 57 30

Fiber (g/d) 4 11 24 18 22 29 41 49

Sugar (g/d) 8 13 68 67 90 80 113 101

Weight Loss – 6 Months

-10-9-8-7-6-5-4-3-2-10

Brehm Foster Samaha

% C

ha

ng

e

Low-Carbohydrate

Low-Fat

* *

*

The Perfect Storm Against Carbohydrates

● Increasing obesity rates.

● Increases in % carbohydrate dietary intakes.

● Some scientific evidence indicating low carbohydrate diets are more effective for promoting weight loss.

Changing the Tide for Carbohydrates

● Oldways Pasta Meeting (Rome, Feb 2004).Bringing experts together to discuss the issue and promote the healthy carbohydrate message.

● Individuals on Atkins diet suffering CHD events and suing.

● New scientific evidence.

Daily Caloric Food Consumption

Area

Year 1965 1975 1985 1998

Estim

2015

Estim

2030

World 2358

100%

2435 2655 2803

119%

2940 3050

129%

Dev 2054

100%

2152 2450 2681

131%

2850 2980

145%

Indust 2947

100%

3065 3206 3380

115%

3440 3500

119%

Modified from Table 1 p. 15 Diet, Nutrition, and the Prevention of Chronic Disease, WHO Technical Report 916, 1-160, 2003 , increases in sugar and fat intake

Low compliance on both diets.

Foster GD et al. N Engl J Med. 2003;348:2082-90.

Weight loss on Low-carbohydrate diet

-12

-10

-8

-6

-4

-2

0

0 3 6 9 12

Month

Ch

ang

e in

Wei

gh

t (%

)

Conventional diet

Low-carbohydrate diet

Base-line Values Carried Forward

Percent change in LDL-C

Foster GD et al. N Engl J Med. 2003;348:2082-90.

-20

-15

-10

-5

0

5

10

0 3 6 9 12

Month

Ch

ang

e in

LD

L C

ho

lest

ero

l (%

)Low-carbohydrate diet Conventional diet

0

1

2

3

4

5

6

7

% Reduction

A O WW Z

Diets

Weight Loss (at 12 months)

Tufts Popular Diet Study

Dansiger, Gleason, Wen, Griffin, Selker, Schaefer JAMA 2005;293:43-53

Tufts Popular Diet Study

Compliance at 12 months:

21/40 still on Atkins (A),

20/40 on Ornish (O),

26/40 on Weight Watchers (WW),

26/40 on Zone (Z).


The End of the Revolution?

Diabetes and Gestational Diabetes Trends Among Adults in the U.S., BRFSS

1990, 1995 and 20011990 1995

2001

Mokdad AH, Ford ES, Bowman BA, et al. Prevalence of obesity, diabetes, and other obesity-related health risk factors, 2001. JAMA 2003 Jan 1;289(1).

No Data <4% 4%-6% 6%-8% 8%-10% >10%

Diabetes Prevention Program Study

• Metformin vs. Lifestyle (exercise & diet)

31 % 58 % Diabetes Complications

2.1 Kg 5.6 Kg Weight Loss

Diabetes Prevention Program Research Group. N Engl J Med 2002;346:393.

STOP-NIDDM Trial

N= 1,386 subjects with Impaired Glucose Tolerance

(high risk of developing diabetes)

~50% of subjects received acarbose (α-glucosidase inhibitor, ↓ rate of glucose absorption).

RESULT: ↓ 36% progression to diabetes

Chiasson J-L, Josse RG, Hanefeld M, et al. JAMA 2003;346:393.

STOP-NIDDM Trial


CVD Events

Acarbose

↓ 49% RR

STOP-NIDDM Trial


Hypertension

(new cases)

Acarbose

↓ 34% RR

Glycemic Index

Low vs. High GI Foods:

Blood Glucose Increments after Spaghetti, White and Wholemeal Bread (n=9)

0

1

2

3

4

5

6

7

8

Time (h)

Blo

od G

luco

se (m

mol

/L)

Spaghetti

White Bread

Wholemeal Bread

0 1 2 3

<0.05

<0.005 <0.001<0.005

<0.02

Jenkins et al. Diab Care 1983;6:155-9

GLYCEMIC INDEX RANKINGFoods grouped into high, intermediate and low classes according to GI :

High GI (GI >90) Most Breads Plain Crackers Most Breakfast Cereals

Instant Mashed Potatoes Millet Corn chips

Medium GI (GI 70-89) All Bran Oatmeal Most biscuits or cookies Rice

Buckwheat Sweet Corn Boiled New Potatoes Yam Sweet Potatoes

Low GI (GI <69) Pasta Pumpernickel Bread Parboiled Rice Most legumes (dried)

Nuts Barley Bulgur (cracked wheat)

High GI

Intermediate GI

Low GI

Mixed meals are predictablein subjects with type 2 diabetes

0

20

40

60

80

100Single food Mixed meal

GI

Bornet et al. Am J Clin Nutr 1987, 42:1192

Postprandial Metabolism and Oxidative Stress

Ciriello, 2003

Metabolism of Carbohydrates

“With regard to the glycemic effects of carbohydrates, the total amount of carbohydrate in meals or snacks is more important than the source or type”

American Diabetes Association, (Diabetes Care Jan 2004;27:37s).

Metabolism of Carbohydrates

●“Regulation of blood glucose to achieve near normal levels is a primary goal in the management of diabetes, and, thus, the dietary techniques that limit hyperglycemia following a meal are likely important in limiting the complications of diabetes.”

●“A recent analysis of the randomized controlled trials that have examined the efficacy of the glycemic index on overall blood glucose control indicates that the use of this technique can provide an additional benefit over that observed when total carbohydrate is considered alone.”

American Diabetes Association, (Diabetes Care Sept 2004;27:2267).

Low vs High GI Diet: a Meta-Analysis% Difference in Glycated Proteins

Gilbertson et al. 2001Komindr et al. 2001Giacco et al 2000Luscombe et al 1999Jarvi et al 1999Lafrance et al 1998Frost et al 1993Wolever et al 1992Wolever et al 1992Fontvieille et al 1992Brand et al 1991Jenkins et al 1991Fontvieille et al 1988Collier et al 1988

% -35 -25 -15 -5 5 15

Mean %difference in 14 studies = -7.4% (CI -8.8 to -6.0%)Mean %difference in 14 studies = -7.4% (CI -8.8 to -6.0%)

OVERALL RESULTOVERALL RESULT

Brand-Miller et al, Diabetes Care 2003;26:2261-67

Glycemic load and risk of diabetesNurses Health Study 6 years of follow-up in 65,000 women

Salmeron et al. JAMA 1997;277:472-7

11.28

1.51

2.5

0

1

2

3

Low Medium High High GI +low fibre

Glycemic load

Relative risk of Type 2

Diabetes

P < 0.03adjusted

forknown risk

factors

Glycemic load and risk of heart attackNurses Health Study 10 years of follow-up in 65,000 women

1 0.981.21

1.49

1.9

0

1

2

Q1 Q2 Q3 Q4 Q5Lowest Glycemic load Highest

Relative risk of CHD

P < 0.0001 adjusted for known risk factors

Liu et al. Am J Clin Nutr 2000,71: 1455

Frost et al. Lancet 1999;353:1045-8

Glycemic index and HDL-cholesterol

Liu et al. Am J Clin Nutr 2002;75:492-8

Glycemic Load and C-Reactive Protein

Glycemic load and risk of colon cancerCase-control study (1950 cases and 4154 controls) from Italy

11.2 1.2

1.6

1.9

0

1

2

Q1 Q2 Q3 Q4 Q5Lowest Glycaemic load Highest

Relative risk of colon

cancer

p < 0.001 for trend, adjusted for age, sex, education, exercise, fibre, alcohol and

energy

Franceschi et al. Ann Oncol 2001, 12: 173

Future Research Directions

• Short-term (mechanistic) studies of pasta and other low glycemic index foods on oxidative stress and inflammatory biomarkers.

• Longer-term effectiveness (real world) studies to assess low glycemic index diets in diabetes and heart disease prevention and control.

Summary

• The low carbohydrate diet craze appears to be coming to an end, although some low-carb sentiment remains.

• Low glycemic index diets by virtue of slowing absorption appear to be protective for a number of chronic diseases and may be effective in body weight control.

Postprandial GlycemiaLow vs High GI mixed meals

Laine et al. Diabetes Care 1987, 10:387

80

90

100

110

120

130

140

0 30 60 90 120 150 180

High GI mixed meal Low GI mixed meal

0

1

2

3

4

5

0 30 60 90 120 150 180 210 240

Healthy subjects (n = 13) Type 2 subjects (n = 16)

Brand et al. Diabetes Care 1991, 14:95

Time (min)

***

Postprandial InsulinemiaLow vs High GI mixed meals

Laine et al. Diabetes Care 1987

Ser

um

In

suli

nU

/mL

Time (min)

0

20

40

60

80

100

120

0 30 60 90 120 150 180

High GI meal Low GI meal

0

20

40

60

80

100

120

0 30 60 90 120 150 180

Coulston et al. Diabetes Care 1987

Healthy subjects Type 2 subjects

3 Meals a Day vs. Nibbling Diet

Tufts Popular Diet Study: Atkins (low carb), Ornish (low fat), Weight Watchers (calories),

& Zone (glycemic load)


Objective:

To assess adherence rates and the effectiveness of 4 popular diets for weight loss and cardiac risk factor reduction

Summary

Industry – must take the high road.

1. Proactive.

2. Responsible. 3. Choice.

Summary

Industry – must take the high road.

1. Proactive: Take the lead in promoting healthy diets and activities and in dealing with childhood obesity. : Work with government and health agencies to address this issue.

2. Responsible: Advertising and labeling.

3. Choice: Healthy foods and portion sizes.

Pasta, Low Glycemic Index Diets and Health Dr. Cyril W.C. Kendall Department of Nutritional...

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