TRANS FATTY ACIDS (READING FOR ILETS)

TRANS FATTY ACIDS

A recent editorial in British Medical Journal (BMJ), written by researchers from the University of Oxford, has called for food labels to list trans fats as well as cholesterol and saturated fat.

Trans fat (or Trans fatty acids) are type of unsaturated fatty acid. They occur naturally in small amounts in food produced from ruminant animals e.g. milk, beef and lab. However, most of the trans fatty acids in the diet are produced during the process of partial hydrogenation (hardening) of vegetable oils into semi-solid fats. They are therefore found in hard margarines, partially hydrogenated cooking oils and in some bakery products, fried foods, and other processed foods that are made using these.

Trans fatty acids have an adverse effect on certain chemicals, known as lipids, which are found in the blood and have been shown to increase the heart disease. They also increase LDL-cholesterol (the ‘bad cholesterol’) and decrease HDL-cholesterol (the ‘good cholesterol’). They may also have adverse effects on cardiovascular disease risk that are independent of an effect on blood lipids (Mozaffarian et al. 2006).

In a recent review of prospective studies investigating the effects of trans fatty acids, a 2% increase in energy intake from trans fatty acids was associated with a 23% increase in the incidence of heart disease. The authors also reported that the adverse effects of trans fatty acids were observed even at very low intakes (3% of total daily energy intake, or about 2-7g per day) (Mozaffarian et al. 2006).

However, in this recent review it is only trans fatty acids produced during the hardening of vegetable oils that are found to be harmful to health. The public health implications of consuming trans fatty acids from ruminant products are considered to be relatively limited.

Over the last decade, population intakes of trans fatty acids in the UK fell and are now, on average, well below the recommended 2% of total energy set by the Department of Health in 1991 at 1.2% of energy (Henderson et al.2003). This is not to say that intakes of trans fatty acids are not still a problem, and dietary advice states that those individuals who are in the top end of the distribution of intake should still make efforts to reduce their intakes.

Currently, trans fatty acids in the foods are labelled in the USA, but not in the UK nad Europe. The UK Food Standards Agency (FSA) is in favour of the revision of the European directive that governs the content and format of food labels so that trans fatty acids are labelled. This should enable consumers to make better food choices with regard to heart health (Clarke & Lewington 2006).

Recognising the adverse health effects of trans fatty acids, many food manufacturers and retailers have been systematically removing them from their products in recent years. For example, they have been absent for some time from major brands of margarine and other fat spreads, which are now manufactured using a different technique. Also, many companies now have guidelines in place that are resulting in reformulation and reduction or elimination of trans fatty acids in products where they have in the past been found, such as snack products, fried products and baked goods. Consequently, the vast majority of savoury biscuits and crisps produced in the UK do not contain partially hydrogenated oils. Similarly, changes are being made to the way bakery products are manufactured. For example, a leading European manufacturer of major brands of biscuits, cakes and snacks has recently announced that these are now made without partially hydrogenated vegetable oils a transition that began in 2004. Alongside these changes, the manufacturer has also reported a cut in the amount of saturates. It is clear that a major technical challenge in achieving such changes is to avoid simply exchanging trans fatty acids for saturated fatty acids, which also have damaging health effects.

Foods that are labelled as containing partially-hydrogenated oils or fats are a source of trans fatty acids (sometimes ‘partially-hydrogenated’ fats are just labelled as ‘hydrogenated’ fats). These foods include hard margarines, some fried products and some manufactured bakery products e.g. biscuits, pastries and cakes.

It is important to note that intake may have changed in the light reformulation of foods that has taken place over the past six yesrs in the UK as referred to earlier. Furthermore, the average intake of trans fatty acids is lower in the UK than in the USA (where legislation has now been introduced). However, this does not mean there is room for complacency, as the intake in some some sectors of the population is known to be higher than recommended.

Questions 1-7

Do the following statements agree with the information given in Reading Passage?

In boxes 1-7 on your answer, write

TRUE                       if the statement agrees with the information

FALSE                    if the statement contradicts the information

NOT GIVEN          if there is no information on this

1.    Trans fatty acids are found in all types of meat.

2.    Health problems can be caused by the consumption of small amounts of trans fatty acids.

3.    Experts consider that the trans fatty acids contained in animal products are unlikely to be a serious health risk.

4.    In Britain, the intake of trans fatty acids is continuing to decline.

5.    The amount of saturated fats in processed meats is being reduced by some major producers.

6.    It is proving difficult to find a safe substitute for trans fatty acids.

7.    Some people are still consuming larger quantities of trans fatty acids than the experts consider safe.

Question 8-13

Complete the sentences below

Choose NO MORE THAN THREE WORDS from the passage for each answer.

Write your answers in boxes 8-13 on your answer sheet

8.    Scientists at Oxford University propose that information about trans fatty acids should be included on _____________

9.    In food manufacture, the majority of trans fatty acids are created when _________ are solidified.

10.              The likelihood of person developing _______ is increased by trans fatty acid consumption.

11.              In the UK, the ___________ established a limit for the safe daily consumption of trans fatty acids.

12.              Partially hydrogenated oils are also no longer found in most UK manufactured salty _________

13.              Consumption of trans fatty acids in _________ is now higher than in the UK

ANSWER KEY

1.    False

2.    True

3.    True

4.    Not Given

5.    Not Given

6.    True

7.    True

8.    food labels

9.    vegetable oils

10.              heart disease/ cardiovascular disease

11.              Department of Health

12.              biscuits and chips

13.              (the) USA