(Press-News.org) Researchers from the University of the Basque Country (UPV/EHU, Spain) have been the first to discover the presence of certain aldehydes in food, which are believed to be related to some neurodegenerative diseases and some types of cancer. These toxic compounds can be found in some oils, such as sunflower oil, when heated at a suitable temperature for frying.
"It was known that at frying temperature, oil releases aldehydes that pollute the atmosphere and can be inhaled, so we decided to research into whether these remain in the oil after they are heated, and they do" María Dolores Guillén, a lecturer in the Pharmacy and Food Technology Department at the UPV, tells SINC.
The researcher is a co-author of a project that confirms the simultaneous presence of various toxic aldehydes from the 'oxygenated α, β-unsaturated group' such as 4-hydroxy-[E]-2nonenal. Furthermore, two have been traced in foods for the first time (4-oxo-[E]-2-decenal and 4-oxo-[E]-2-undecenal).
Until now these substances had only been seen in bio-medical studies, where their presence in organisms is linked to different types of cancer and neurodegenerative diseases such as Alzheimer's and Parkinson's.
The toxic aldehydes are a result of degradation of the fatty acids in oil, and although some are volatile, others remain after frying. That is why than be found in cooked food. As they are very reactive compounds they can react with proteins, hormones and enzymes in the organism and impede its correct functioning.
The research, which is published in the Food Chemistry journal, involved heating three types of oil (olive, sunflower and flaxseeds) in an industrial deep fryer at 190 ºC. This was carried out for 40 hours (8 hours a day) in the first two, and 20 hours for the linseed oil. The latter is not normally used for cooking in the west, but it has been chosen due to its high content in omega 3 groups.
VIDEO:
Researchers from the University of the Basque Country have been the first to discover the presence of certain aldehydes in food, which are believed to be related to some neurodegenerative...
Click here for more information.
More toxic aldehydes in sunflower oil
After applying gas chromatography/mass spectrometry techniques, the results show that sunflower and linseed oil (especially the first) are the ones that create the most toxic aldehydes in less time. These oils are high in polyunsaturated fats (linoleic and linolenic).
Adversely, olive oil, which has a higher concentration of monounsaturated fats (such as oleic), generate these harmful compounds in a smaller amount and later.
In previous studies, the same researchers found that in oils subjected to frying temperatures, other toxic substances, alkyl benzenes (aromatic hydrocarbons) were found. They concluded that of the oils studied, olive oil is the one that creates the least.
The dose makes the poison
"It is not intended to alarm the population, but this data is what it is, and it should be taken into account" Guillén highlights, who points out the need to continue researching to establish clear limits regarding the risk of these compounds. "On some occasions the dose makes the poison" the researcher reminds us.
Spanish regulations that control the quality of heated fats and oils establish a maximum value of 25% for polar components (degradation products coming from frying). Nonetheless, according to the new study, before some of the oils analysed reach this limit, they already have a "significant concentration" of toxic aldehyde.
The study counts all the aldehydes (not the just the harmful ones) that are generated during frying. Furthermore, the authors present a model that allows the prediction of how any hypothetical oil will evolve in the same conditions, if they know its initial fatty acid composition.
INFORMATION:
References:
Maria D. Guillén, Patricia S. Uriarte. "Aldehydes contained in edible oils of a very different nature after prolonged heating at frying temperature: Presence of toxic oxygenated α, β unsaturated aldehydes". Food Chemistry 131 (3): 915-926, April 2012 (available on line since September 2011). Doi: 10.1016/j.foodchem.2011.09.079.
Toxic aldehydes detected in reheated oil
2012-02-23
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
Researchers solve puzzle of proteins linked to heart failure
2012-02-23
Sudden cardiac death is a risk for patients with heart failure because the calcium inside their heart cells is not properly controlled and this can lead to an irregular heartbeat. New findings published in PLoS ONE, which reveal mechanisms that underlie this life-threatening risk, provide new possibilities for fighting it.
The study, led by researchers from the University of Bristol's School of Physiology and Pharmacology, show how two individual but very similar proteins cooperatively adjust the amount of calcium inside the heart cells, and how this dual regulation may ...
What can animals' survival instincts tell us about understanding human emotion?
2012-02-23
Can animals' survival instincts shed additional light on what we know about human emotion? New York University neuroscientist Joseph LeDoux poses this question in outlining a pioneering theory, drawn from two decades of research, that could lead to a more comprehensive understanding of emotions in both humans and animals.
In his essay, which appears in the journal Neuron, LeDoux proposes shifting scientific focus "from questions about whether emotions that humans consciously feel are also present in other animals and towards questions about the extent to which circuits ...
Family history -- a significant way to improve cardiovascular disease risk assessment
2012-02-23
A new study by researchers at The University of Nottingham has proved that assessing family medical history is a significant tool in helping GPs spot patients at high risk of heart disease and its widespread use could save lives.
Previous research has suggested that family history can be an indicator of a patient's risk of heart disease but at present family medical details are not systematically collected and used by GPs in cardiovascular risk assessment.
This first-ever clinical investigation into systematically collecting family history as part of cardiovascular ...
In food form, some probiotics have a better chance to promote health
2012-02-23
Amsterdam, February 22, 2012 – Functional foods containing bacteria with beneficial health effects, or probiotics, have long been consumed in Northern Europe and are becoming increasingly popular elsewhere. To be of benefit, however, the bacteria have to survive in the very hostile environment of the digestive tract. A group of scientists from the Norwegian University of Life Sciences in Ås, Norway have developed a "model gastric system" for evaluating the survival of bacteria strains in the human digestive system, and determined that some bacteria strains survive better ...
Birds sing louder amidst the noise and structures of the urban jungle
2012-02-23
Sparrows, blackbirds and the great tit are all birds known to sing at a higher pitch (frequency) in urban environments. It was previously believed that these birds sang at higher frequencies in order to escape the lower frequencies noises of the urban environment. Now, researchers at the University of Copenhagen and the University of Aberystwyth have discovered that besides noise, the physical structure of cities also plays a role in altering the birds' songs.
Urban birds sing differently and at a higher frequency than woodland birds in an effort to penetrate the wall ...
World of Warcraft boosts cognitive functioning in some older adults
2012-02-23
For some older adults, the online video game World of Warcraft (WoW) may provide more than just an opportunity for escapist adventure. Researchers from North Carolina State University have found that playing WoW actually boosted cognitive functioning for older adults – particularly those adults who had scored poorly on cognitive ability tests before playing the game.
"We chose World of Warcraft because it has attributes we felt may produce benefits – it is a cognitively challenging game in a socially interactive environment that presents users with novel situations," ...
Geological cycle causes biodiversity booms and busts every 60 million years, research suggests
2012-02-23
A mysterious cycle of booms and busts in marine biodiversity over the past 500 million years could be tied to a periodic uplifting of the world's continents, scientists report in the March issue of The Journal of Geology.
The researchers discovered periodic increases in the amount of the isotope strontium-87 found in marine fossils. The timing of these increases corresponds to previously discovered low points in marine biodiversity that occur in the fossil record roughly every 60 million years. Adrian Melott, a Professor of Physics and Astronomy at the University of Kansas ...
Toxins from diseased brain cells make diseases of the brain even worse
2012-02-23
Sometimes our immune defence attacks our own cells. When this happens in the brain we see neurodegenerative diseases such as dementia, Alzheimer's and Parkinson's disease. But if the the immune defence is inhibited, the results could be disastrous. Researchers at the University of Copenhagen have now discovered one of the molecular combat mechanisms in the brain that gets out of control in these diseases. In time this may enable targeted therapies to slow down the disease without harming the patient.
"In their attempt to recover, diseased brain cells release chemical ...
Invasive plant protects Australian lizards from invasive toad: Study
2012-02-23
An invasive plant may have saved an iconic Australian lizard species from death at the hands of toxic cane toads, according to research published in the March issue of The American Naturalist. It's an interesting case of one invasive species preparing local predators for the arrival of another, says Richard Shine, a biologist at the University of Sydney who led the research.
Cane toads were introduced in Australia in the 1930s to control beetles that destroy sugar cane crops, but the toads quickly became an ecological disaster of their own. They produce toxins called ...
San Francisco Maritime Law Journal Article Reviews Maximum Cure Rule
2012-02-23
The rights of seamen who are injured while aboard vessels arise out of a complex array of established admiralty law principles, statutory provisions such as the Jones Act and general maritime law, as well as regulatory oversight. One of the most important duties of maritime lawyers is holding ship owners to their responsibility to provide maintenance and cure to injured crewmembers.
Maintenance under the Jones Act means daily compensation to cover the costs of basic food and shelter that the seaman would have received aboard the vessel while working. Maintenance rates ...