Health assessment of fatty acids

The BfRshort forGerman Federal Institute for Risk Assessment prepares health assessments in cases where there is a need for official evaluation of the addition of fatty acids to foods.

For example, the BfRshort forGerman Federal Institute for Risk Assessment has evaluated the two omega-3 fatty acids DHA and EPA regardless of the source (fish oil, novel algae oils or fatty acid ethyl esters) according to the criteria of the provision of Article 8 of Regulation (EC) No 1925/2006 of the European Parliament and of the Council of 20 December 2006 on the addition of vitamins, minerals and certain other substances to foods.

In addition, the BfRshort forGerman Federal Institute for Risk Assessment has assessed the intake of trans fatty acids through food for the population in Germany - and found that high trans fatty acid intakes observed in recent years were mainly caused by high levels in baked goods and convenience products, which was most evident in younger age groups.

Fatty acids are components of natural fats and oils. They are not present in free form in food. They primarily provide food energy, although certain fatty acids also have special functions in the organism. All natural fats contain both saturated and unsaturated fatty acids. Every fat and every oil has an individual fatty acid pattern.

Most animal fats (milk fats, beef tallow, pork and poultry lard) and some vegetable fats (cocoa butter, coconut fat, shea butter and palm fats) contain mainly saturated and monounsaturated fatty acids. Cheese, butter, sausage and meat as well as chocolate and other confectionery and various convenience products are typical foods that contain these fats.

Margarines are water-in-oil emulsions with a spreadable consistency in which hydrogenated vegetable fats (technical hydrogenation) are mixed with non-hydrogenated vegetable oils. The proportion of saturated fatty acids in margarines is therefore higher than in the corresponding vegetable oils.

Incomplete hydrogenation of vegetable oils (partial hydrogenation) produces trans fatty acids. Although trans fatty acids are unsaturated, they have similar physical properties to saturated fatty acids.

Most vegetable oils and fish oil contain predominantly unsaturated fatty acids. In addition to oils, typical foods with a high proportion of unsaturated fatty acids are seeds, fruit and nuts as well as fatty fish species (salmon, herring, mackerel), cod liver and cod liver oil. Unsaturated fatty acids are divided into omega-3 and omega-6 fatty acids according to the number and position of their double bonds. The omega-3 fatty acid alpha-linolenic acid and the omega-6 fatty acid linoleic acid are essential, as they cannot be produced in the human organism but must be ingested with food.

Good sources of alpha-linolenic acid are oils from walnuts, rapeseed, soya and linseed. The particularly long-chain omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are formed in the body from alpha-linolenic acid, which can also be absorbed by eating fatty sea fish (salmon, mackerel and tuna). An abundant intake of DHA and EPA through one or two fish meals per week is said to reduce the risk of cardiovascular disease. Fish oil or DHA and EPA are also available as dietary supplements. Furthermore, DHA-rich oils from marine microalgae are authorised as novel food in the EU and may be added to food supplements and used to enrich foods.

The omega-6 fatty acid linoleic acid is contained in large quantities in diesel, soya and sunflower oil. Arachidonic acid is formed from it in the body and is also absorbed from meat and sausage products.

The long-chain, polyunsaturated fatty acids DHA, EPA and arachidonic acid are starting materials for the formation of cell hormones, which play a role in the regulation of inflammatory processes and the immune response. Omega-3 and omega-6 fatty acids are metabolised by the same enzyme system. In order to maintain a healthy balance of long-chain polyunsaturated omega-3 and omega-6 fatty acids, the two fatty acids alpha-linolenic acid and linoleic acid should be consumed in as close a ratio as possible.

Natural trans fatty acids are produced in the rumen of ruminants by microorganisms and are mainly found in dairy and meat products (beef and sheep). Trans fatty acids, on the other hand, which are formed by the partial hardening of unsaturated fatty acids in vegetable oils, are mainly found in many popular foods such as baked goods, fast food products, snacks, biscuits, waffles, fried foods and spreads.

High doses of trans fatty acids increase the LDL cholesterol level and lower the HDL cholesterol level in the blood. Therefore, no more than 1 % of food energy should be consumed as trans fatty acids. In 2019, Regulation (EU) 2019/649 was adopted, according to which the content of industrially produced trans fatty acids - i.e. those produced by the partial hardening of fats - in foods intended for retail sale may not exceed 2 g per 100 g of fat. This is to ensure that the intake of trans fatty acids is as low as possible as part of a nutritionally appropriate diet. Quality assurance measures by manufacturers to minimise the trans fatty acid content of spreadable fats, baked goods, confectionery and finished products are still important in order to keep the trans fatty acid intake of consumers low.