Many health-minded individuals
understand that eating fried or overcooked foods is unhealthy due to the
chemical transition of normally stable fats to trans-fats that have been shown
to dramatically increase heart attack risk. Researchers from the University of
the Basque in Spain publishing in the journal
Food Chemistry are the first to
discover compounds released from common cooking oils that significantly increase
the risk of neurologic degenerative diseases and a variety of different
cancers.
Breakdown chemical structures
known as aldehydes are formed in cooked vegetable oils such as sunflower oil
when heated to normal frying temperatures, and are also released into the air where
they can be inhaled. Alternate food preparation methods such as roasting,
steaming and broiling are safe methods of cooking foods to avoid the dangerous
release of aldehydes and afford a shield against cancer forming particles and
neurodegenerative decline.
Many Common Vegetable Oils Produce Dangerous Aldehydes When Heated
Prior studies have identified the
health degrading nature of aldehydes, where their presence in organisms is
linked to different types of cancer and neurodegenerative diseases such as Alzheimer's
and Parkinson's. Researchers also know that these compounds remain in vegetable
oils after they have been used to fry foods and wanted to determine how they
interact with proteins, hormones and enzymes in the body to impede its correct
functioning.
The study
team heated three types of oil (olive, sunflower and flaxseeds) in an
industrial deep fryer at 190 degrees Celsius for a period of forty hours
(twenty hours was used for the flaxseed oil). This length of time was used to
approximate oils used commercially at a restaurant where fryers remain heated
for extended periods of time. The oils were then analyzed using gas
chromatography/mass spectrometry techniques.
Extra Virgin Olive Oil is a Healthier Oil for Cooking
Researchers found that the
sunflower and flaxseed oils degraded significantly and are the ones that create
the most toxic aldehydes in the least amount of frying time. These oils are
high in polyunsaturated fats (linoleic and linolenic) and breakdown quickly to form
the health-demoting aldehyde compounds that permeate the air and penetrate into
the food. Olive oil, known to be high in monounsaturated fat, generates
aldehydes to a lesser degree and after cooking much longer.
The research team concluded “The fact that significant concentrations of
these toxic compounds were found in some oils … is a cause of concern for human
health.” Although the scientists did not use coconut oil in their tests,
studies have shown that the medium-chain fatty acid does not rapidly convert to
deadly trans fats when heated, and may be less likely to produce aldehydes when
compared to other vegetable oils. While fried foods are not part of a healthy
eating plan, it is important to avoid cooking with low flash-point oils that
produce aldehydes and increase the risk of neurologic disorders and cancer.