Bioactive Foods L6-7

Question 1

What are the following an example of?

• Flavonoids
• Tannins
• Lignins

Answer 1

Plant polyphenols

Question 2

What are the following an example of?

• Flavonoids
• Catechins
• Isoflavones

Answer 2

Polyphenols

Question 3

Name up to 7 foods in which polyphenols are found.

Answer 3

• Vegetables
• Fruits
• Cereals
• Legumes
• Nuts
• Tea
• Wine

Question 4

Name up to 4 foods/food-groups in which phytosterols are found.

Answer 4

• Nuts
• Seeds
• Unrefined plant oils
• Legumes

Question 5

Name up to 5 foods in which carotenoids are found.

Answer 5

• Carrots
• Squash
• Sweet potato
• Spinach
• Kale

Question 6

Name up to 3 foods/food-groups in which tocopherols are found.

Answer 6

• Vegetable oils
• Nuts
• Germ portion of grains

Question 7

Name the 2 types of vegetables in which organosulphur compounds are found.

Answer 7

• Cruciferous vegetables
• Allium vegetables

Question 8

Plant _______ = Characterized by the presence of more than one phenol unit/benzene ring per molecule; varying numbers of hydroxyl (-OH) carbonyl (-CO) and carboxylate (-COOH) groups.

Answer 8

Polyphenols

Question 9

___________ =

• Soyabean is a particularly rich source
• Occur in unfermented foods predominantly as beta-glucosides
• In fermented foods (e.g. tofu) occur as aglycones
• Major circulating forms (after metabolism in intestine and liver) are conjugates to glucuronic acid (i.e. glucuronides) and sulphates

Answer 9

Isoflavones

Question 10

Quote the critical review of health effects of isoflavones on bone health.

Answer 10

“A suggestion but no conclusive evidence that isoflavones from the sources studied so far have a benefical effect on bone health”.

Question 11

Quote the critical review of health effects of isoflavones on cardiovascular effects.

Answer 11

“The consumption of whole soyabean foods and soyabean protein isolate has some beneficial effects on lipid markers of cardiovascular disease in health post-menopausal women. The consumption of isolated isoflavones does not affect blood lipid levels or blood pressure.”

Question 12

Why are effects of bioactive food components so difficult to demonstrate in human subjects?

Answer 12

• Compliance with intervention
• Confounding factors; requirement for tight inclusion/exclusion criteria:
  
  • Background diet
  • Medication
  • Other lifestyle factors (e.g. smoking, physical activity level)
• Influences of genotype

Question 13

Name a rich source of Resveratrol.

Answer 13

Red grapes.

Question 14

Define a bioactive food component.

Answer 14

A nonessential biomolecule in foods that can modulate a metabolic process(es).

Question 15

Summary of bioactive food components, sources and reported effects

Question 16

Isoflavone Structure

The 3 phenol rings connected in this way is the basic structure of all polyphenols.

Very similar structure to ______ so many of their in vivo actions are due to either mimicking ______ or causing an antagonistic effect at ______ receptors. (Both for and against ______ effects).

Answer 16

Oestrogen

Question 17

Genistein promotes the conversion of white adipose tissues to brown adipose tissues. Brown adipose tissue wastes ____1____ (therefore could be used for obesity). Only proven in vivo. This action is known to be nothing to do with an effect on ____2____ receptors. (Proven by adding ____2____ receptor antagonist → adipose effect still happened).

Answer 17

1. Energy
2. Oestrogen

Question 18

Differences in structures of polyphenols mainly occur on phenol __.

Answer 18

A

Question 19

Equol is a metabolite of Diadzein.

Interestingly there is a quite clear phenotype with ability to produce Equol in that some of us can and some of us cannot. Most likely due to the type of bacteria present in the gut that determines this. Some evidence suggests it may be a beneficial metabolite.

Equol and Diadzein are both ______

Answer 19

Isoflavones