Cooking with olive oil destroys its health benefits and makes your food harmful.
Hoax or Fact:
This is a wide spread belief about cooking with Olive Oil, that it destroys its health benefits and produces harmful chemicals to make your food poisonous. The claim, as such, is partially fact. Olive oil has been heavily promoted as healthy oil, so let us also examine how good it really is!
Olive Oil & Health Benefits
Olive oil is a fat obtained from the fruit of olive tree (Olea europaea), a traditional tree crop of the Mediterranean region. For its various benefits, olive oil is used in cosmetics, medicine, cooking and soaps. It is rich in monounsaturated fatty acids and is the main source of fat in the Mediterranean diet, which is associated with a low death rate from cardiovascular diseases compared to North Americans and Northern Europeans.
In 2003, researchers conducted a study to conclude that olive oil is a major contributing factor to the health benefits of the Mediterranean diet, which includes more eggs, vegetables, and higher vitamin intake. In other words, the study reinforces the value of olive oil in promoting health as part of the Mediterranean diet -- not the olive oil alone. Also, it is not the olive oil in itself, but the polyphenols in it that are beneficial; they can also be found in many fruits, vegetables, wine, tea and cocoa. As opposed to Saturated fats and Trans fats, the monounsaturated fatty acids (MUFAs) found in Olive oil are considered healthy dietary fat, which may help lower your risk of heart disease by improving related risk factors.
Various preliminary clinical studies have shown other health benefits of olive oil, which are not yet been established with sufficient scientific evidence. It is because of this reason; producers of olive oil may mention the restricted health claim on product labels.
Considering the aforementioned facts and studies, it can be said that Olive oil may be one of the more healthful oils, but it is still a fat high in calories and should be used in moderation. Olive oil is 'better' than other oils as a part of healthy (Mediterranean) diet, but not that it in itself is good for health.
Cooking with Olive Oil
The issue of cooking with olive oil is that healthy phenols found in olive oil are compromised by heat and beyond its Smoke Point temperature, nasty chemicals may be produced that will end up in food. Apart from these concerns, overheating olive oil can impart a burnt flavor to your food and remove some of the taste as well. It is a fact that vegetable oils and olive oil containing high amount of MUFAs have relatively low smoke points and cannot withstand large amount of heat. Talking about this cooking concern with olive oil, Mercola states:
Olive oil is primarily a monounsaturated fat. This means that it has one double bond in its fatty acid structure. The problem with olive oil is its overabundance of oleic acid (70%), which creates an imbalance on the cellular level that can inhibit prostaglandin production, which can increase the risk of breast cancer and heart disease.
It is a fact that there are some concerns about the high amount of oleic acid present in olive oil, but the consumption of oleate in olive oil has been associated with a decreased risk of breast cancer. Some studies have shown the olive-oil-rich Mediterranean diet cuts breast cancer. More research is needed on this though. Mercola says olive oil is a smart fat to include in your diet in a non-heated form, and promotes virgin coconut oil as best one for cooking.
The smoke point of olive oil depends on many factors, and the type of olive oil used also decides the cooking concerns. Explaining them, Fox News states:
If it's a salad dressing recipe or even a baking recipe, that's fine — but if it asks you to sauté, grill, roast, or (gasp) fry, it's really bad advice — the smoke point of extra-virgin olive oil (high quality olive oil with reduced oleic acid content) is about 375 to 405 degrees, and if you go past it, as you surely will when using one of these high-temperature cooking techniques, you'll produce all sorts of nasty chemicals that will end up in your food. Some common examples include peroxides, aldehydes, ketones, and hydroperoxides, all of which are toxic. But you don't just end up producing bad substances; you end up destroying the good ones, too. At 356 degrees, antioxidants start to say goodbye — tocopherols are the first to go.
So apart from the quality of olive oil that is to be used in moderation with healthy diet, the cooking temperature holds the key to avoid damage of healthy compounds in the oil and prevent the production of any unwanted nasty chemicals. Owing to these concerns, it is suggested to use refined olive oil (having much higher smoke point) when cooking at high temperature. It is marketed as "extra-light," "light tasting," or even just "olive oil". The refined olive oil has a free acidity, expressed as oleic acid, of not more than 0.3 grams per 100 grams (0.3%). While the smoke point of olive oil is considered to be around 325°F - 375°F, that of refined olive oil is around 468°F (242°C). The extra-virgin olive oil is suggested for finishing a dish, not for cooking it.