Health benefits of olive oil (and others)

[MeSci]

Here is a recent article on the website of the Alliance for Natural Health, with links to original papers. It starts:

The benefits of cooking with olive oil made headlines last week after revelations from a recent study in Food Chemistry may have turned more than one version of ‘conventional wisdom’ on its head. The Spanish researchers found that deep-frying and sautéing vegetables in Mediterranean extra virgin olive oil (EVOO) resulted in increased total phenolic compounds within the food. These phenolics are phytonutrients (plant chemicals) that are known to have anti-oxidative, anti-inflammatory, antimutagenic and anticarcinogenic properties. It was also found that cooking in water reduced the phenol content.

This study follows a systematic review, conducted also by Spanish researchers, published in April last year, that showed that consumption of fried vegetables, especially ones cooked in olive oil, did not directly increase cardiovascular disease risk. The review did however show that high rates of consumption of fried vegetables did tend to increase weight gain, which is indirectly correlated with CVD and other chronic diseases.

but it also says:

These most recent findings may have heartened those who are well aware of the health benefits of EVOO, some of which are due to the oil’s own high polyphenolic content, but who have been reluctant to use the oil for cooking for fear of heat damage and loss of some benefits. Others may have been somewhat enlightened, especially those who thought that frying of any kind, regardless of the oil used, would always degrade the quality of food. Despite these findings, there is still good evidence to suggest that certain types of frying, such as deep frying, as well as the over-consumption of fried foods, does more harm than good. There are many reasons why over-frying can be bad for foods, this not only being due to the denaturing of food ingredients by heat, but also through the formation of toxic compounds, such as acrylamide, aldehydes and glycation end products.