DfES School Food Consulation
Submission of tfX - the campaign against trans fats in food. 29 March 2005
As extended and amended, 31 March 2005.
- What are trans fats?
- What health problems are associated with trans fats?
- Does school food contain trans fats?
- What specific health problems regarding trans fats apply in a school context?
- What other factors apply to the use of hydrogenated oil?
- The present situation.
- Our recommendations.
- Further information and contacts.
We welcome the initiative of Government to improve the quality of school meals, including nutritional quality. The tfX campaign was founded for a specific purpose - to bring about the exclusion of health-damaging trans fats from the human diet. However we will also address the question of optimising the fatty acid profile in the school diet for nutritional benefit.
2. What are trans fats?
Trans fats are fats (triglycerides of fatty acids) which contain trans fatty acids. These are the trans isomers of unsaturated fatty acids, which normally exist in nature in the cis configuration.
The trans fatty acids of concern from a health perspective are the articifial trans fatty acids, especially those formed during the process of hydrogenation (hardening) of unsaturated oil. The negative health impacts which we refer to below arise solely as a result of eating these artificial trans fatty acids. Naturally-occurring trans fatty acids, such as those found in dairy produce and the meat of ruminant animals (many of them conjugated trans fatty acids) present no apparent health risks.
In the following paragraphs, therefore, the term "trans fat" is used to describe only trans fats formed from the artificial trans fatty acids. The main source of such trans fat is hydrogenated oil. This is mostly labelled as "[partially] hydrogenated vegetable oil". However sometimes the vegetable oil will be named, for example as "soybean oil" or "palm oil".
3. What health problems are associated with trans fats?
A wide range of health problems are associated with trans fats. These problems are believed to arise because they are not found in nature, and so we have no inherited ability within our bodies to recognise them and deal with them appropriately.
The following negative effects have been reported. Dietary trans fats
- raise LDL (Low-Density Lipo-proteins, known as "bad" cholesterol) and lower HDL (High-Density Lipo-proteins, known as "good" cholesterol) levels.
- promote the formation of arterial plaque, leading to circulation problems, high blood pressure, heart disease and stroke.
- decrease the response of human cells to insulin, a factor in both adult-onset (type 2) diabetes and obesity.
- when consumed by pregnant women, introduce themselves into the tissues of unborn babies and reduce their birth weight.
- when consumed by breast-feeding mothers, enter into mothers milk, reducing cream levels and the amount of essential fatty acids.
- promote the onset of Alzheimer's disease and accelerate mental decline among elderly people.
- produce severe allergic and other reactions among sensitive persons, with reports of strong hayfever symptoms, migraine and yeast infections.
- assimilate into cell membranes to levels as high 20 percent, weakening their structure and protective function.
- block the beneficial action of the essential Omega-3 and Omega-6 fatty acids.
- reduce the elasticity of blood vessels.
- predispose to cancer, multiple scelerosis, diverticulisis and obesity.
- weaken the immune system, increasing susceptibtibility to infections.
- inhibit the action of enzymes that destroy toxic and carcinogenic chemicals.
More information on these health impacts, including references to original scientific papers, are to be found on the tfX website at www.tfx.org.uk.
4. Does school food contain trans fats?
We are not aware of any specific information on the quantities in which trans fats occur in the school diet. However it is probable that the school diet does contain significant levels of trans fat, and is richer in trans fat than the UK diet as a whole. This is because:
- school meals contain many processed and manufactured foods. Food processors like to use the hydrogenated oils which contain trans fats because they are chemically stable and the products that contain them therefore have long shelf lives. As hardened fats they also provide the mechanical qualities required in many food processing applications.
- school meals contain a lot of deep-fried food. Hydrogenated oil is often preferred for deep frying because it is more chemically stable at frying temperatures than plain vegetable oil, and will therefore last longer in deep fryers before it needs changing.
- school meals include a lot of baked goods such as cakes, and pastry-based foods, such as pies. Cakes and pastries are often made with hydrogenated oil due to its chemical stability and mechanical attributes.
- As a result of the tiny budgets available for school meals, there is strong pressure on caterers to use the cheapest possible ingredients and prepared foods. Since hydrogenated oils are extremely cheap, they are likely to be used in preference to more expensive alternatives such as cream and butter, both within school kitchens, and in bought in foods such as ice cream, cakes, pizza, pies and vegetarian burgers.
In the absence of specific information on trans fat levels in school meals, it must therefore be assumed that school food, in general, is rich in trans fat. We advise that research be undertaken to verify the actual levels encountered.
5. What specific health problems regarding trans fats apply in a school context?
A number of the health problems associated with trans fats are of specific concern to school children. These are:
- Because children are growing, a high proportion of ingested trans fat is likely to be incorporated into the bodies of school children, for example in adipose tissue and cell membranes. For that reason the effects of dietary trans fat in children may be long term, taking many years before the trans fats are lost through natural "turn over" of body fat.
- Trans fats inhibit the utilisation of the essential omega-3 and omega-6 fatty acids. These fatty acids play an important role in the development of the juvenile brain and nervous system, and any reduction in their effective availability is thus highly undesirable. This is all the more the case where the diet is already deficient in essential fatty acids, as is certainly the case for large numbers of children.
- Trans fats are well-known to interfere with the cellular response to insulin, reducing sensitivity, and to be a factor in the development of Type 2 Diabetes. Given the increased incidence of Type 2 Diabetes, it may be that children's intake of trans fats is a causative factor. Another related phenomenon is in the increased levels of obesity encountered among school children. Diminished response to insulin can also lead to obesity, since it is harder for the body to convert reserves of fat into usable energy.
- Many girls go on to become pregnant soon after leaving school, or even become pregnant while at school. If eating trans fat, the unborn baby will therefore assimilate trans fats into its tissues, and if breast-fed, will ingest further trans fat. This is known to reduce birth weight, reduce cream and essential fatty acid content of mother's milk, and reduce the baby's utilisation of essential fatty acids.
- Trans fat intake is strongly associated with Alzheimer disease and cognitive decline amongst elderly people. While this is of no direct relevance to school children it is nonetheless indicative that trans fats are damaging to the brain, and it may be that these damaging effects extend to as yet untested damage to mental development and well-being across the age spectrum.
- While most school children are unlikely to suffer from cardiovascular disease while at school or in the near future after leaving school, it would appear prudent to avoid risk factors such as dietary trans fats which will increase their susceptibility to cardiovascular disease in the longer term future.
6. What other factors apply to the use of hydrogenated oil?
When a liquid oil is [partially] hydrogenated, there are two effects:
- the conversion of unsaturated oil to saturated fat
- the conversion of unsaturated oil in the normal cis configuration to the trans isomer.
So far we have discussed the negative health impacts of trans fats. However we should also take into account:
- the destruction by hydrogenation of monounsaturated and polyunsaturated oils that are of positive health benefit, including essential omega-3 and omega-6 fatty acids where present.
- the increase in dietary saturated fat.
- that a number of people are intolerant of hydrogenated oil and exhibit severe responses which may include migraine, hayfever-like symptoms and BV (bacterial vaginosis).
In replacing liquid vegetable oils with hydrogenated vegetable oils, therefore, the food industry is converting health-promoting fats with both health-damaging trans fats, and saturated fats which are generally held to be in surplus in the UK diet as a whole.
7. The present situation.
We are concerned to discover that there appears to be no existing regulation of, or guidance about, the quantities of trans fat in children's food. For example, the school food guidelines which came into effect on 1 April 2001 (to be found on the DfES website at www.dfes.gov.uk/schoollunches/) make no mention of trans fats or hydrogenated oils.
Insofar as these guidelines refer to dietary fats, the concern is wholly focussed on the total quantity of fat, and saturated fats. In both cases the presumption appears to be that fat is bad, and that saturated fat is especially bad. Specific advice is even given to avoid coconut oil, although this is actually a very healthy oil.
The DfES also places considerable reliance on the The Caroline Walker Trust (CWT) Nutritional Guidelines for School Meals, to the extent of publishing these guidelines on its own website. Again, the CWT Guidelines contain no reference to trans fats or hydrogenated oils, and the exclusive focus as far as fats are concerned is on limiting both total fat, and saturated fat. The CWT advise that total fatty acids should provide no more than 35 percent of food energy, and that saturated fatty acids should provide no more than 11 percent of food energy.
We also note that neither CWT nor DfES make any mention of the essential omega-3 and omega-6 essential fatty acids, as found in oily fish and flax oil, which play a particular role in the development of the juvenile brain and nervous system.
8. Our recommendations.
Based on the above considerations tfX recommends that:
- Nutritional standards and guidelines for school meals should include standards and guidance limiting the levels of trans fats.
- These limits should be set at a very low level, effectively eliminating trans fats from school food.
- The best way of reducing trans fat levels in school food may be to ban the use of hydrogenated oils and fats as ingredients. We realise that the level of trans fat in hydrogenated oil is highly variable, and in the case of fully hydrogenated oil that there is no trans fat present. However as a general rule the lower the fraction of trans fat in hydrogenated oil, the higher the fraction of saturated fat, and saturated fat is, in general, already in dietary surplus. In addition a minority of persons suffer from allergic or other intolerance to hydrogenated oil and this will satisfy their dietary needs.
- Positive efforts be made to optimise the fatty acid profile of school food. As a general rule:
- trans fatty acids should be eliminated;
- monounsaturated and polyunsaturated fatty acids should be encouraged, subject to a general limit on total fat intake, and present in roughly equal proportions;
- saturated fatty acids should be constrained to no more than one third of the overall fatty acid intake (in line with CWT guidance).
- the essential omega-3 and omega-6 fatty acids should be present in an average school meal at a level to satisfy 100% of daily dietary needs;
- These requirements should be legally binding on all providers of school meals.
- DfES, in association with the Food Standards Agency and Local Education Authorities, should monitor the fatty acid profile of school food to ensure adherence to the principles set out above, and take appropriate action enforcement action as necessary.
9. Further information and contacts.
Further information on trans fats is available on the tfX website at www.tfx.org.uk .
tfX may be contacted by way of the campaign's founder: Oliver Tickell, 379 Meadow Lane, Oxford OX4 4BL. email: email@example.com.