29 NOVEMBER 2000
10/01
DRAFT RISK ANALYSIS REPORT
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Note: This report is the ' Full Assessment ' as referred to in Section 15 of the Australia New Zealand Food Authority Act (1991). Public comments are now sought before completion of a Final Risk Analysis Report (referred to as the ' Inquiry ' under Section 16 of the Act). See under ' Invitation for Public Submissions ' for details. |
Full Report [ pdf 362 kb ]
EXECUTIVE SUMMARY
Background
An application was received from Unilever Foods on 14 March 2000 to amend the Food Standards Code to approve the use of phytosterol esters derived from vegetable oils as novel food ingredients under Standard A19 - Novel Foods. Phytosterol esters are prepared by the reaction of phytosterols with fatty acid methyl esters or free fatty acids. The free phytosterols are structurally related to cholesterol and occur naturally at low levels (up to 0.9%) in common vegetable oils. Phytosterol esters are considered to be novel food ingredients because they do not have a history of significant human consumption by the broad community in Australia and New Zealand at the proposed levels of dietary exposure.
Phytosterol esters, when incorporated into the table spreads at levels of 13.7% are reported to be an effective way of lowering total and LDL-cholesterol levels in the blood.
Issues addressed
Current and proposed use
At the time of gazettal of the Novel Food Standard (December 1999), phytosterol esters were being used in two brands of table spreads, one marketed by Unilever and one by Goodman-Fielder. Phytosterol esters can continue to be used in foods until clause 2 of Standard A19, which deals with the prohibition of the sale of novel foods, comes into force on 16 June 2001. By October 2000, there was also a phytosterol ester-containing mayonnaise product, a coleslaw dressing product and a breakfast bar product being marketed by Goodman-Fielder. In the future, Goodman-Fielder has indicated they wish to market a phytosterol ester-containing white, fibre-increased bread product and a mixed flake breakfast cereal product. Dairy Farmers have expressed an interest in marketing phytosterol ester-containing low fat yoghurt product, a low fat soy beverage product, and a low and reduced fat cheese product. Arnott' s Biscuits/Campbell' s Soups have indicated an interest in marketing phytosterol ester-containing biscuit and soup products.
Safety evaluation
The safety of phytosterol esters has been examined in studies in experimental animals as well as in humans. The studies in animals indicate that these substances are poorly absorbed from the gastrointestinal tract, have low toxicity, are not genotoxic, and have no effect on reproductive parameters. Excretion is via the faeces both as free phytosterol and phytosterol esters. The human studies did not provide any evidence of adverse effects associated with consumption of table spreads containing 13.7% (w/w) phytosterol esters at dietary intakes of 3.3 g/day for 3.5 weeks and 1.6 g/day for one-year (calculated as free phytosterols). There is no long-term data to demonstrate the safety of phytosterol esters at higher levels of exposure.
There is also evidence from these studies that the plasma levels of carotenoids, which have antioxidant activity, are reduced although the levels are still considered to be within normal variation. This includes beta -carotene, which is a precursor for vitamin A. While not a concern per se at these levels of exposure , there is no data on the effect on carotenoid levels at higher phytosterol exposure levels.
Estimated dietary exposure
Dietary modelling was conducted on the existing and proposed uses of phytosterol esters in various foods. The results showed that the level of exposure in the 3.5-week and one-year human studies was approximately the estimated intake for mean consumption consumers and 95th percentile consumption consumers of table spread enriched with phytosterol esters at 13.7% (w/w). Consumption of other foods containing phytosterol esters in addition to table spreads would lead to higher levels of dietary exposure. The use of phytosterol esters in some foods such as cereals, biscuits and breads may lead to higher levels of intake than necessary to achieve the cholesterol-lowering effect in the target groups, since the intake of these foods is not as self-limiting as the intake of table spread. Use of phytosterol esters in these foods may also provide a greater potential for intake in the non-target groups.
Effect on cholesterol absorption
The effectiveness of phytosterol esters to reduce blood cholesterol has not been specifically assessed as part of this application. However, the human studies that have been examined do indicate that plasma cholesterol was reduced by approximately 5% and LDL-cholesterol by 7-8% over a one-year period by the consumption of table spread containing 13.7% (w/w) phytosterol esters. No studies have been conducted using other foods containing phytosterol esters. Given that phytosterol esters exert their effect in the gut, the food matrix may be critical to their efficacy, and therefore should be tested before any labelling statements are used which imply a beneficial effect of phytosterol esters in foods other than table spreads.
Advice to consumers
With phytosterol ester-enriched foods, there is a clear intention to market the reported beneficial effects of phytosterol esters on blood cholesterol and therefore it is important that these foods be consumed as part of a healthy diet that is low in saturated fats. A mandatory advisory statement to this effect is proposed. There is also a need to protect at-risk groups in relation to any potential reduction in plasma carotenoid levels as a result of phytosterol ester intake. These at-risk groups are children, pregnant and lactating women. A mandatory advisory statement indicating that phytosterol ester-enriched foods are unsuitable for these groups is also proposed. The use of phytosterol ester-containing table spreads should not be considered a substitute for cholesterol-lowering medication and a mandatory advisory statement is proposed that will indicate the need for individuals on such medication to seek medical advice regarding the use of the product. In relation to the ability of phytosterol esters to reduce cholesterol absorption, this will be considered in the light of the current review of the framework for health claims.
Risk assessment
Overall, the data support the safety of phytosterol esters at the level of intake which would be achieved by their addition to table spreads at 13.7% (w/w), but there is insufficient data to demonstrate their safety at the higher levels of intake which could occur from their use in a broader range of foods.
Risk management
Given the limited data on the potential long-term effects of phytosterol esters on clinical pathology parameters and specifically on plasma carotenoid levels at exposure levels higher than 1.6 g free phytosterols/day, dietary exposure should be restricted to the level which would be obtained from the consumption of table spreads containing 13.7% (w/w) phytosterol esters. Phytosterol ester preparations must also comply with the established specifications. This approach is consistent with the conclusions of the regulatory impact assessment.
In order to ensure that phytosterol ester-enriched table spreads are used appropriately by consumers, the following mandatory advisory statements should be used:
- A statement to the effect that the product should be consumed in moderation as part of a diet low in saturated fats.
- A statement to the effect that the product is unsuitable for infants, children, and pregnant or lactating women.
- A statement to the effect that consumers already on cholesterol-lowering medication should seek medical advice about using the product.
Conclusions
- There are no public health and safety concerns associated with the use of phytosterol esters in table spreads at a maximum concentration of 13.7% (w/w). The available data is insufficient to assess the safety of phytosterol esters at higher levels of exposure.
- There is some evidence from the available data that phytosterol esters when incorporated into a table spread at 13.7% (w/w) can reduce the level of plasma cholesterol. There is no data available in relation to their effectiveness in this regard when present in other foods.
- Permission for use should be limited to table spreads at a maximum concentration of 13.7% (w/w) phytosterol esters. Mandatory advisory statements are required to ensure that consumers use phytosterol ester-enriched table spreads appropriately.
- The proposed changes to the Food Standards Code are consistent with the section 10 objectives of the Australia New Zealand Food Authority Act 1991 and the regulatory impact assessment.
Full Report [ pdf 362 kb ]