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Trans Fats / Trans Fatty Acids

Trans Fats / Trans Fatty Acids
Table Of Contents
  1. Chemical Structure
  2. How trans fatty acids are formed
  3. Health risks of trans fats
  4. Influence of Emotions by Trans Fats
  5. What's the Need?
  6. Occurrence
  7. Trans fats have already been banned from foods in the United States

Trans fatty acids, which belong to the unsaturated fatty acids (chemically partially hydrogenated fats), should not be present in a healthy diet. Especially trans fats formed through industrial processing are harmful to health.

According to Harvard University, trans fats are the worst type of fat for the heart, blood vessels, and the rest of the body 1.

According to research from Denmark, vegans have the lowest intake of trans fatty acids compared to the general population 2.

Chemical Structure

Fatty acids generally consist of a chain of carbon atoms with hydrogen atoms bound to them. The chemical structure of trans fatty acids is in the trans configuration. The hydrogen atoms on the carbon atoms of the double bond are located on opposite sides. In a cis configuration, the hydrogen atoms are on the same side.

How trans fatty acids are formed

Trans fatty acids are mostly formed during the industrial hydrogenation of unsaturated fatty acids. The process of fat hardening (hydrogenation) solidifies liquid oils (increases the melting point) to prevent products from becoming rancid. During hydrogenation, the chemical structure of unsaturated fatty acids changes into saturated fatty acids, eliminating the double bonds in the carbon chain and saturating it completely with hydrogen atoms 3. However, in partial hydrogenation, which is commonly used in margarine production, not all fatty acids are completely hydrogenated, resulting in the formation of trans fatty acids.

Even when heating oil with a high content of polyunsaturated fatty acids such as flaxseed oil in pans or deep fryers, trans fats can be formed. However, baking and frying with canola oil at normal and/or extreme temperatures did not significantly contribute to an increase in the amount of trans fatty acids 4.

In addition, extremely intense exposure to light can also contribute to the formation of trans fats.

Health risks of trans fats

Industrial trans fats have negative effects on health, such as cardiovascular problems, insulin resistance, female infertility, impairment of fetal development, and a decrease in cognitive functions 5.

Studies have shown that consuming a diet high in trans fats can lead to a smaller brain size and degenerative diseases such as Alzheimer's 6 7. Other study findings have indicated that trans fats may be associated with an increased risk of heart disease and higher inflammation levels in women 8 9.

Trans fats significantly increase bad LDL cholesterol levels and maintain or keep the level of good HDL cholesterol at the same level, which can lead to heart disease. 1011 1213 14. A newer study from 2015 reaffirms that trans fats are associated with higher overall mortality due to circulatory and heart diseases. 15.

Furthermore, trans fats contribute to insulin resistance and can thus cause diabetes. 16.

The metabolic reactions of essential fatty acids such as linoleic acid (Omega-6) and alpha-linolenic acid (Omega-3), as well as the prostaglandin balance, are negatively affected by the inhibition of the enzyme delta-6-desaturase caused by trans fatty acids. 17 18. Through delta-6-desaturase, linoleic acid and alpha-linolenic acid are converted into other fatty acids required by the body. For vegans, the conversion into other Omega-3 and Omega-6 fatty acids is particularly important, as the fatty acids synthesized by the body are hardly or not found in plant-based foods. Prostaglandins are hormone-like substances involved, among other things, in the regulation of inflammatory reactions.

Trans fats also lead to muscle loss due to impaired absorption or utilization of amino acids from dietary intake 19.

Influence of Emotions by Trans Fats

According to study findings from 2015, lower dietary intake of trans fats is associated with improved emotion regulation 20. Reduced consumption is linked to increased positive emotions and decreased negative emotions.

What's the Need?

The consumption of trans fats should be kept as low as possible or completely avoided according to EFSA (European Food Safety Authority) 21. The recommended daily maximum intake should not exceed 1% (approximately 3g) of the daily energy requirement 22.

For example, if an additional 2% of daily energy intake is obtained from trans fats, the cardiovascular risk increases by 23% 23.


From a vegan perspective, trans fats are mainly found in processed foods such as fried foods, chips, confectionery, ice cream, snacks, margarine, hydrogenated vegetable oil, salad dressings, and baked goods - also to increase the shelf life of the products. 24 25.

Trans fats have already been banned from foods in the United States

In June 2015, the American Food and Drug Administration (FDA) announced the ban of all artificial trans fats from food 26. Food manufacturers in the United States have three years to remove partially hydrogenated fats from their products.

In Denmark, oils and fats with more than 2% trans fats have been prohibited since 2004 27.