Why storing vegetable oils correctly is important
According to numerous nutritional recommendations, vegetable oils should be part of a healthy diet as they are a rich source of unsaturated fatty acids. Using a new process, a German research team has now discovered for the first time considerable amounts of substances in plant oils that can damage the genetic material.
Researchers at the Justus Liebig University of Giessen have detected up to eight different genotoxins in 31 plant oils. The compounds discovered have the potential to trigger changes to DNA. The results were recently presented in the journal “Food Chemistry”.
What are epoxidized fatty acids?
Linolenic acid is an essential omega-3 fatty acid found in many vegetable oils. When this acid comes into contact with oxygen, it undergoes a process called oxidation. This process can produce potentially harmful compounds called epoxidized fatty acids.
Epoxidized fatty acids can have negative health effects. For example, they can trigger inflammation, increase oxidative stress and cause damage to cell membranes.
Genotoxins detected in 31 vegetable oils
As part of the current study, the team led by Professor Dr. Gertrud Morlock and graduate student Daniel Meyer used a new method called high-resolution mass spectrometry to determine the amount of such potentially harmful compounds in 31 different vegetable oils.
In this way, the working group was able to detect up to eight different genotoxins in the plant oils for the first time. Common oils were examined, including organic products such as:
- Olive oil,
- sunflower oil,
- rapeseed oil,
- safflower oil,
- Linseed oil,
- Sesame oil,
- coconut oil,
- Peanut oil,
- hemp oil,
- Walnut oil.
Oxidized linolenic acid is a source of genotoxicity
According to the research team, genotoxic substances trigger changes to DNA, i.e. the genetic material of cells. As the team was able to demonstrate in all samples, oxidized linolenic acid represents a “source of genotoxicity.” The longer an oil was stored in air, the more genotoxic compounds it contained.
In particular, the unsaturated fatty acids, which in themselves have a very positive effect on the body, are particularly susceptible to oxidation and therefore to changes that are potentially harmful.
“Our analyzes are of great importance because vegetable oils are found in almost all foods, in many dietary supplements and cosmetics,” emphasizes study lead author Morlock.
First evidence of this kind
The new method has now made it possible to detect the extent of the genotoxins contained for the first time. “The methods currently used in food analysis do not accurately reflect the pollutant load of genotoxins in complex foods such as oils, because their signals are overlaid by overpowering other signals,” explains Morlock.
Many genotoxins can be detoxified by the liver
It is currently unclear what specific effects exposure to genotoxic compounds has on humans. The team has already carried out initial tests on this. “Initial studies of simulated metabolism with liver enzymes show that most genotoxins can be detoxified by a healthy liver,” reports Morlock.
Store vegetable oils correctly
However, the scientist emphasizes that further studies are necessary to understand the effect of such substances on the body. In addition, the storage of vegetable oils should be reviewed to find conditions that maintain the stability of the composition over the recommended period of use. (vb)