What are Phytosterols?
Phytosterols or plant sterols are natural constituents of the lipid fraction of oilseeds, fruits, seeds and other natural extracts. They are normally isolated from the unsaponifiable fraction (campesterol, stigmasterol, Beta – sitosterol). The chief source of commercial available plant sterols is deodorizer distillate from soybean oil or palm oil or they are sourced from tall (pine) oil.

The Beta Sitosterol Story

     

Consumption of 2g of Beta-sitosterol, or its esterified hydrogenated product, can reduce serum cholesterol by 10-20%.

Beta-sitosterol is found in vegetable oils, avocados and is concentrated in certain margarines and dressings.

Commercial Incorporation in Food Oils
Beta-sitosterol is not freely soluble in oils and fats (2 – 3%) and so the free sterol is hydrogenated to reduce its propensity to oxidation then is esterified with fatty acid esters (usually from rapeseed oil). The resultant products are called stanol esters and are added at 8% to spreads.

Beta-Sitosterol

• Cost about 20 – 30 USD/kg ($48 NZD)
• Sourced from tall oil
• Sourced from deodorizer distillate (palm & soya)

• Esterification normally required for effective incorporation in oils.
• Overseas sourcing, purification and processing results in high price.
• Patents produced on a soluble form (ascorbyl ester).
  

Sources of Beta Sitosterol in NZ

• Tall oil pitch
• Avocado oil / stone

• Dressing / mayonnaise
• Bread
• Snack bars
• Confectionery chews

Dosage and efficancy .(plant sterols)

• Normal intake from food supply ca. 250 – 300mg per day
• For cholesterol reduction need 1.5 – 3.0g per day
• Stanol esters are hardly absorbed
• Free sterols have some absorption

		PRO-ACTIV	LOGICOL
Plant Stanols		8%	8%
F.A.M.E.	16:0	11.6	8.0
	18:0	2.7	5.2
	18:1	31.7	54.8
	18:2	46.5	17.6
	18:3	2.8	7.0
	Others	4.7	7.4

Claims for Phytosterol Functional Foods

Monsanto (USP 6, 113, 972) (Sept 5 2000)	Protein complex based on Plant Sterols from corn fibre oil has increased bio availability.
Kao Corporation (Oct 31, 2000) USP 6, 139, 897 USP 6, 025, 348	Oil or fat containing Diacylglycerols and Phylosterols for cooking oils to reduce Cholesterol.
Redeem Inc (August 2001)	Anticholesterolemic edible oil, Phylosterols, Vitamin E and Cycloartenols instead of the Stanols. Also replaces "Statins" - the drugs for Cholesterol reduction.
Amway Corp (June 2001) USP 6, 241, 987	Dietary supplement containing saw palmetto, pumpkinseed and nettle root.
Kraft Foods (August 2001) USP 6, 274, 574	Use of mesophase - stabilised compositions for delivery of cholesterol-reducing Sterols and Stanols in food products (low fat foods).

ANZFA Regulations

• Phytosterol esters approved in June 2001.
• Application for tall oil phytosterols (A417) to Standard A19 at 8%.
• The product should be consumed in moderation as part of a diet low in saturated fats and high in fruit and vegetables.
• The product is not recommended for infants, children and pregnant women.
• Consumers on cholesterol lowering medication should seek medical advice.
• Only product is table-spread with saturated fatty acids < 28%.

Safety

• Intestinal absorption of beta-sitosterol is approximately 5% of intake.
• It is excreted by the liver into the bile.
• A tenfold increase in the intake of beta-sitosterol increases the plasma level by less than a factor of two.
• Sitostanol is not or is hardly absorbed.
• No adverse effects have been found.
• Spreads can slightly decrease the plasma carotene concentration if dietary intake is greater than 1.6g (20g spread).

Benign Prostatic Hyperplasia (BPH)
“A slow enlargement of the fibromuscular and epithelial structures within the prostate gland.”

• Medical treatments/drugs include alpha-receptor blocking agents and 5-alpha-reductase inhibitors.
• Plant extracts have been widely used for this purpose.
• Dosages of 20mg of beta-sitosterol per day utilised for 6 months.
• Since 1974 sitosterol and its glycoside (Harzol TM) has been used in Germany usually at a dose of 3 x 20 mg per day.
• Saw palmetto (0.2% beta-sitosterol) has been used for many years.
• Sitosterol preferred to sitostanol for treatment.
• Sitostanol completely unabsorbed may block the absorption of beta-sitosterol.

The Future for Phytosterols

• Clinical trials to show that potential consumption greater than 2-3g poses no risk to any consumer sector.
• Sort out the debate between free sitosterol and stanol esters.
• Alternative products - low fat spreads, dressings, yoghurt, dairy desserts, oil blends, dietary supplements.
• Solubility issues.
• Purity and composition issues.
• Price and availability.

Margarine / Spreads Development

• Pre 1972 - Margarine act prohibited the manufacture of consumer margarine.
• 1972 - Polyunsaturated margarine on prescription.
• Post 1972 - Only PUM allowed for consumer sale.
• Specification P>40 S<20. P mainly omega 6 (80% fat).
• 1990 Margarine Act repealed.
• 1990-2000 - Spreadable butter, canola margarine, olive oil margarine.
• 2000 - Phytosterol containing margarines/spreads.
• 2001 - Growth of monounsaturates.
• Future - Functional designer spreads
  • Omega 3 (fish)
  • Selenium
  • Vitamin E
  • Omega 3 (linolenic)
  • Polyphenols

Adequate Intakes of Essential Fatty Acids
The most recent international workshop on this topic recommended the following AI in the absence of data for Dietary Reference Intakes

Monounsaturates and Olive Spreads

	Olivio	Olivani
Sell Price (Pakn’Save)	3.50
Manufacturer	Unilever (Aus)	Goodman Fielder NZ
Fat Content (%)	70	75
Olive Oil (Min)	21%	30
Saturated (%)	27 Max	-
Trans (%)	0.9 Max	-
Mono (%)	55 Min	-
Poly (%)	10 Min	-
Salt content (Na)	362mg	393
Salt Content (%)	0.9%	1.0%
Vitamins A + D Level	not stated	No
Cholesterol Free	Statement	Statement
Additives
Soybean Lecithin	Yes	No
Emulsifier	Yes	Yes
Antioxidant	No
Preservative (202)	Yes	No

Omega – 3 fatty acids

• Two main types from either fish or certain vegetable oils or cereals such as flaxseed (linseed)
• LCPUFA – EPA (eicosapentaenoic acid) DHA (docosahexaenoic acid)
• Technological problems to incorporate into foods
  1. Quality of raw material
  2. Taste and flavour
  3. Stability of final product and shelf life
• Product applications
  1. infant formulae (EPA & DHA)
  2. bread
  3. eggs

Omega 3 (Alpha - Linolenic)

• Highest source is Linseed (flaxseed) oil (65%)
• Also in canola (11%), Soybean (8%) and horse depot fat.
• Recommended intake 1-2g per day.
• Ratio of Linoleic: Linolenate should be < 4/5:1.
• Food delivery systems - spreads, dressings, bread or snack bars.
• NZ sourced flaxseed oil (South Island) good quality - low in oxidation products and bottled in dark under inert gas.
• Walnuts.

• Knowledge about their physiological function - 25 years.
• Reduction in mortality from CHD.
• Reduction in inflammatory diseases (arthritis, Psoriasis, Eczema).
• Possibly have an action in reducing depression.
• Recommended intake ~ 1-2g per day.
• Normally source oils are high in P.V., A.V. and have off-flavours.
• Food delivery systems include spreads, yoghurts, bread and dressings.

Vitamin E (Tocopherols)

• Common form of dietary supplement or food antioxidant is the synthetic dl-alpha-tocopherol (a racemate)
• Studies have shown that the natural mixtures (8 isomers) have higher biological activities.
• As polyunsaturates increase then vitamin E intake should increase to 20x level in saturates/monounsaturates diet.
• Typical daily intake Western Population ~ 12-15 mg (18.6 I.U.)
• Proposed intake 100-400 mg per day.
• Vitamin E deficiency indicated by pentane in the breath due to Lipid Oxidation.
• Margarines / spreads should contain a minimum of 250mg / kg Vit E.

• Traditionally added to margarine to simulate butter (also Northern hemisphere requirements).
• Also important for the elderly who may not be out in the sunshine very much.

Dietary Guidelines for Lipids

Total Fat	30-33% of total energy
Saturated fat (and trans fat)	< 8% total energy (~18g)
Polyunsaturated fat	8 -10% total energy (10-18g)
Alpha Linolemic acid	2g per day
LC PUFA	0.6 - 1.5g per day
Linolenic	< 8-10g per day
Monounsaturates	~ 26% of energy (60g / day)
Dietary Cholesterol (for at risk)	358mg men 240mg women
Vitamins A, D & E	No agreed recommendations in print
Beta Sitosterol	1.5 - 2.0g per day (if required)

The Designer Oil / Spread / Fat Formulation

• High in monounsaturates (60-70%).
• Linoleic / Linolenic Ratio < 5:1 with a total of 10g.
• Saturates < 28%
• Trans ~ Zero
• Lc PuFA ~ 2%
• Vitamin E ~ 200-700 ppm
• Vit A & D added
• Containing beta - sitosterol or esters at 1-8%
• Containing Lutein, Lycopene / Chlorophyll.