Proanthocyanidins and Anthocyanins

Question 1

Proanthocyanidins

Answer 1

Proanthocyanidins are known as condensed tannins and are formed from building blocks including catechin and epicatechin. They are predominant in the seeds and skin of grapes

Question 2

Proanthocyanidins: Food sources

Answer 2

• Grapes (skin and seeds(
• Cranberries, blueberries, elderberry, bilberries.
• Cocoa.
• Apples, cinnamon, cashews.
• Maritime pine bark (pycnogenol)

Question 3

Proanthocyanidins: Functions

Answer 3

Cardiovascular health
Immune modulation
Neurological health
Anti-cancer

Question 4

Proanthocyanidins: Cardiovascular health

Answer 4

• Potent antioxidant properties preventing LDL oxidation.
• Enhance nitric oxide promoting vasodilation
• Improve circulation and capillary integrity. Protect capillaries from oxidative stress.

Question 5

Proanthocyanidins: Cardiovascular health - Therapeutic Uses

Answer 5

• Cardiovascular disease prevention.
• Atherosclerosis.
• Hypertension.
• Peripheral oedema.
• Diabetic retinopathy and neuropathy.

Question 6

Proanthocyanidins: Immune modulation

Answer 6

• Stimulate lymphocyte and macrophage activity.
• Stabilise mast cells inhibit histamine producing enzymes.

Question 7

Proanthocyanidins: Immune modulation - Therapeutic Uses

Answer 7

• Immune support.
• Anti allergic: Allergic rhinitis, asthma / eczema.

Question 8

Proanthocyanidins: Neurological health

Answer 8

Neuroprotective properties against:
* Alzheimer’s by inhibiting beta amyloid aggregation.
* Parkinson’s by protecting dopamine producing cells.

Question 9

Proanthocyanidins: Anti-cancer

Answer 9

Proanthocyanidins have anti cancer properties:
* They can inhibit cell proliferation and induce apoptosis and cell cycle arrest.
* Research suggests an inhibitory effect on cancer stem cells, which are central to tumour initiation and metastasis.

Question 10

Proanthocyanidins: Dosage

Answer 10

• A plant rich diet is considered to provide proanthocyanidins at an amount that promotes general health.
• For specific health conditions, supplemental doses based on grape seed and pine bark extracts can be used (proanthocyandins 100-300 mg daily).

Question 11

Proanthocyanidins: Safety and interactions

Answer 11

• Generally recognised as safe and well tolerated.
• Monitor with antihypertensive medication. Caution with anti-coagulant medications may have additive effects.

Question 12

Anthocyanins

Answer 12

Anthocyanins and their aglycone ‘anthocyanidins’ are blue, red and purple pigments found in a range of plants. They are protective against UV radiation in plants:
* Found in the tissues of plants including leaves, stems, roots, flowers and fruits.

Question 13

Anthocyanins: Food sources

Answer 13

Acai berry, blackcurrant, blueberry, bilberry, cherry,
red grape, purple corn.

Question 14

Anthocyanins: Functions

Answer 14

Cardiovascular health
Type 2 Diabetes
Eye health
Neurological health

Question 15

Anthocyanins: Cardiovascular health

Answer 15

• Antioxidant scavenging ROS. Anti-inflammatory inhibit NFκB. These effects protect against endothelial damage and reduce LDL oxidation.
• Improve blood lipids
  rasie HDLs, lower LDLs, total cholesterol and triglycerides.
• Decrease arterial stiffness and reduce blood pressure.
• increase insulin sensitivity

Question 16

Anthocyanins: Cardiovascular health - Therapeutic uses

Answer 16

• Hypertension.
• Atherosclerosis.
• Dyslipidaemia.
• Protective against peripheral arterial disease and
  coronary artery disease.

Question 17

Anthocyanins: Type 2 diabetes

Answer 17

• Improve insulin secretion and ↑ insulin sensitivity.
• Thought to activate the enzyme AMPK, which:
  ‒ Upregulates GLUT4 (transports glucose into cells).
  ‒ Inhibits glucose production in the liver.
• Antioxidant and anti inflammatory properties help protect against diabetic complications including retinopathy and neuropathy.

Question 18

Anthocyanins: Eye health

Answer 18

• Protect ocular tissue from oxidative stress.
• Improve night vision (protects photoreceptor cells).

Question 19

Anthocyanins: Neurological health

Answer 19

• Able to cross the blood brain barrier to exert neuroprotective effects.
• Reduce damaging effects of processes that contribute to neurodegeneration including oxidative stress, excitotoxicity and glial inflammation.
• Support cognitive performance with improvements in memory and learning.

Question 20

Anthocyanins: Neurological health - Therapeutic uses

Answer 20

Neurodegenerative conditions such as:
* Alzheimer’s disease.
* Parkinson’s disease.
* Motor neurone disease.
To protect against:
* Cerebral ischemia.
* Age related memory loss.

Question 21

Anthocyanins: Dosage

Answer 21

• Moderate amounts of anthocyanins e.g. 1/3 cup of blueberries daily, are associated with reduced risk of cardiovascular disease, Type 2 diabetes and neurological decline (equivalent anthocyanins 25-50 mg).
• Doses of between 25-50 mg daily have shown to support visual health.
• Supplemental doses of up to 640 mg anthocyanins daily in adults have been used for cardiovascular issues with no reported adverse effects.

Question 22

Anthocyanins: Safety

Answer 22

• Dietary intake is recognised as safe and unlikely to cause harm.

Question 23

Anthocyanins: Interactions

Answer 23

• Many anthocyanins have been identified as inhibitors of BRCP mediated transport, theoretically increasing bioavailability of certain drugs including
  – Anticancer agents (mitoxantrone, topotecan,
  tyrosine kinase inhibitors) ; antibiotics
  (fluoroquinolones); β blockers (prazosin).
• High intakes (e.g. from supplements) could increase the risk of bleeding when taken with anticoagulant drugs