1. Lecture 4b-4 Oct. 2010
FIBRE

2. Overview of lecture 4b FIBRE FIBRE STRUCTURE AND CLASSIFICATION
AND EFFECTS
DAT OF FIBRES
FIBRES IN HEALTH AND DISEASE
HOW TO GET HIGHER FIBRE IN THE DIET
   

3. OVERVIEW OF LECTURE 4B CONTINUED
RECOMMENDATIONS FOR FIBRE INTAKE
TOO MUCH FIBRE IN THE DIET
FIBRES AS FOOD ADDITIVES
WHAT IS NEW IN FIBRE RESEARCH
CHOOSING CARBOHYDRATES WISELY
NEXT LECTURE DAY (LECTURES 5A-6C INCLUSIVE)- 18 October 2010
LIPIDS-STRUCTURE
-FUNCTION
-DAT

4. Fibre structure and classification and effects
Insoluble
Cellulose-bran,vegetables
Hemicellulose-bran, whole grains
Lignins-fruits, mature vegetables, flax
Generally-accelerate gi transit, increase
fecal weight(promotes bowel movements),
slow starch digestion,
delay glucose absorption
But can be exceptions

5. Fibre structure and classification and effects continued
Soluble
Pectins-apples, carrots
gums and mucilages- oats, legumes
Generally-delay gi transit,
delay glucose absorption,
lower blood cholesterol
But can be exceptions

6. OTHER FIBRE FUNCTIONS (classifications)
- water holding capacity
viscosity
cation exchange capacity
bile binding capacity
fermentability

7. Fibre digestion, absorption and transport
not digested by small intestine enzymes-why?
bacteria-make short chain fatty acids
water, gas
short chain fatty acids absorbed at large intestine
and transported by blood used for energy

8. Fibre in health
weight control
bulk-less appetite
SOLUBLE AND INSOLUBLE FIBRES
heart disease
soluble fibres lower cholesterol (bile issue)
fibre may displace fat in diet

9. FIBRE IN HEALTH CONTINUED
Cancer
lower colon cancer-maybe by diluting and binding and more rapid excretion of carcinogens
SOLUBLE AND INSOLUBLE FIBRE
Breast cancer lignans (not fibre per se but lignans are part of the fibre fraction of some plants – e.g. flaxseed contains lignans)
-secoisolariciresinol diglucoside (SDG)(an estrogen-like compound that is a lignan) is a found in flaxseed
-metabolites of SDG are produced by bacteria in the large intestine- made reduce breast tumour growth

10. FIBRE IN HEALTH CONTINUED
Diabetes
control weight-diabetes
slow glucose absorption-glucose surge
and rebound associated with diabetes onset
SOLUBLE FIBRES

11. FIBRE IN HEALTH CONTINUED
gastrointestinal health
enhance health of gi tract-healthy intestine easier to block absorption of unwanted constituents
INSOLUBLE FIBRES

12. How to get higher fibre in the diet
Fibre content
High Medium Low
Breads cereal g 2 g g
Rice Group
Breads Whole wheat white
1 slice bread bread
Cereal All shredded rice
½ cup bran wheat krispies
Pasta Whole macaroni
½ cup wheat pasta

13. How to get higher fibre in the diet continued
Fibre content
High Medium Low
4 g 2 g 1 g
Fruit group
1 MEDIUM
OR ½ CUP berries apple melon

14. How to get higher fibre in the diet continued
Fibre content
High Medium Low
4 g g 1 g
Vegetable
group
peas green asparagus
½ CUP beans

15. REMEMBER THAT:
FIBRE FROM NATURAL SOURCES
RATHER THAN COMMERCIALLY
PREPARED FIBRE
IS BETTER BECAUSE
FOODS CONTAIN VITAMINS AND MINERALS
AS WELL AS THE FIBRE

16. DRI RECOMMENDATION FOR FIBRE INTAKE
FOLLOW DRI RECOMMENDATIONS
FOR CARBOHYDRATE INTAKE AND THIS WILL
PROVIDE SUFFICIENT FIBRE
DRI - 14 GRAMS FIBRE/1000 KCAL
(NO DISTINCTION BETWEEN SOLUBLE
AND INSOLUBLE BUT VARIETY IS THE KEY TO BALANCE)

17. TOO MUCH FIBRE IN THE DIET
FLATULENCE
OBSTRUCT GI TRACT IF GREATER THAN 50 G FIBRE /DAY
TOP RECOMMENDATION IS 40 G/D FOR ADULTS (WHO)

18. TOO MUCH FIBRE IN THE DIET CONTINUED
INSOLUBLE FIBRE HAS PHYTATES
THAT CAN BIND MINERALS-
EG CALCIUM, IRON, ZINC
AND MAGNESIUM
PREVENT ENZYME CONTACT

19. TOO MUCH FIBRE IN THE DIET CONTINUED
INCREASES VOLUME OF FOOD
REQUIRED TO MEET ENERGY
REQUIREMENTS
SATIETY BEFORE ADEQUATE
NUTRITION-GENERALLY ONLY A
PROBLEM IF DIET LOW IN MICRONUTRIENTS
OR IN SMALL CHILDREN (SMALL STOMACHS)

20. TOO MUCH FIBRE IN THE DIET CONTINUED
IMPORTANT TO INCREASE WATER INTAKE
WITH INCREASES IN DIETARY FIBRE
-OTHERWISE CONSTIPATION BUT IF HAVE
ENOUGH WATER CAN GET DIARRHEA (BACTERIAL BREAKDOWN OF FIBRE)

21. FIBRES AS FOOD ADDITIVES
PECTIN -COMMON IN FRUITS AND VEGETABLES
-FORMS GEL WHEN SUGAR
AND ACID ADDED
-COMMERCIALLY FROM CITRUS PEELS
AND APPLES
-THICKENING AGENT IN JAMS, JELLIES
TOMATO PASTE

22. FIBRES AS FOOD ADDITIVES CONTINUED
CARBOHYDRATE GUMS- USED AND
THICKENERS AND STABILIZERS
BECAUSE THEY COMBINE WITH
WATER TO KEEP SOLUTIONS FROM
SEPARATING
USED IN GRAVIES, PIE FILLINGS,
JELLIES AND PUDDINGS

23. FIBRES AS FOOD ADDITIVES CONTINUED
GUMS DERIVED FROM GUM ARABIC,
GUM KARAYA, GUAR GUM, LOCUST BEAN
GUM, XANTHAN GUM AND GUM TRAGACANTH
GUMS EXTRACTED FROM SHRUBS, TREES
AND SEED PODS

24. FIBRES AS FOOD ADDITIVES CONTINUED
PECTINS AND GUMS ARE USED IN
REDUCED FAT PRODUCTS TO MIMIC
THE TEXTURE AND VISCOSITY OF FAT

25. FIBRES AS FOOD ADDITIVES CONTINUED
OTHER THICKENING AGENTS AND
STABILIZERS ARE FROM SEAWEEDS
( E.G. AGAR, CARRAGEEN AND ALGINATES)

26. Whats new in fibre research
Khan et al, Canadian Journal of Cardiology 23:
Emphasise fibre in diet to help manage hypertension

27. How to choose carbohydrates wisely
1)increase intakes of whole grains
2)use whole grain products such as oatmeal,
brown rice and whole wheat bread
3)increase consumption of legumes such as
kidney, black and pinto beans)if fresh fruits
not available, choose frozen or
canned fruits without added sugar

28. How to choose carbohydrates wisely continued
4)use whole grain flour for
¼ to ½ the amount of flour in the recipe
5)use less sugar in baking
6)use less added sugars in foods
7)eat fewer high sugar foods
8)use food labels to guides one’s choices