Is olive oil healthy? Here's what the research says.

Various studies have surfaced data that conclude eating a Mediterranean diet reduces risk of mortality and incidence of various cancers.

The data support the concept that a MD has a benefit with respect to these clinical outcomes, i.e., adherence to a MD was associated with reduced risk of overall cancer mortality as well as incidence of colorectal, breast, gastric, prostate, liver, and head and neck cancer. Source

Olive oil is a major constituent of the Mediterranean diet and is often thought to be a contributor to this helpful effect. But are all olive oils healthy? Are some healthier than others? Let's get into 4 levels each one adding to the potential healthful effects you can expect from olive oil.

Level 1 - Extra Virgin

The first step on this ladder is making sure the olive oil is extra virgin. This ensures it meets a few criteria like ensuring the oil extracted from the olives via cold-pressing, not heated up or separated with chemicals in any way. It is ensures it remains an unrefined oil, the cheaper, normal olive oil may be fully refined olive oil or at least blended with it. Refined oil is usually chemically refined to fix some sort of defect. This sort of process destroys any nutritional value the oil may have possessed, and as such should be avoided, this means avoid oils labelled 'light', 'olive oil', or misleadingly 'pure'. Buy only olive oils labelled simply with the words 'extra virgin'.

Level 2 - Organic

Making sure that your extra virgin olive oil is organic is important as it can reduce pesticide residues. Pesticides can remain in soil and water for years. Chronic toxicity can occur with regular exposure to pesticides, even at low levels, and this exposure can lead to serious health issues such as Parkinson's Disease and cancer.

It should also be noted that just because an olive oil is not organic doesn't necessarily mean that it's not high quality. Getting the organic status is quite tough, and many smaller establishments are effectively 'priced out' of obtaining it. Although much rarer, examples of non-organic high quality extra virgin olive oils do exist, such as Bryan Johnson's Blueprint EVOO (extra virgin olive oil).

Level 3 - High in Oleic Acid

Oleic acid is the major fatty acid found in extra virgin olive oil. This monounsaturated fat is the source of many studies, and is said to offer many health benefits, one of which is the reduction of blood pressure.

The International Olive Council have set the range of 55-83% for Oleic acid for olive oils. In addition to it's healthful effects, a large proportion of oleic acid in the oil will lead to a longer shelf life.

Level 4 - High Polyphenols

Arguably the most important factor into whether olive oil is healthy is the polyphenol level of the oil. Polyphenols work mostly as antioxidants in the body, and are constantly being studied in order to expose their health benefits.

Polyphenols have been shown to improve measures that could be considered risk factors for various cardiovascular disease.

Compared to low polyphenol olive oil, high polyphenol olive oil significantly improved measures of malondialdehyde (MD: -0.07µmol/L [95%CI: -0.12, -0.02µmol/L]; I2: 88%; p = 0.004), oxidized LDL (SMD: -0.44 [95%CI: -0.78, -0.10µmol/L]; I2: 41%; P = 0.01), total cholesterol (MD 4.5 mg/dL [95%CI: -6.54, -2.39 mg/dL]; p<0.0001) and HDL cholesterol (MD 2.37 mg/dL [95%CI: 0.41, 5.04 mg/dL]; p = 0.02) Source

As we can see from the quote above, high polyphenol extra virgin olive oil was shown to improve measures such as total cholesterol and oxidized LDL compared to low polyphenol. This data was from a meta-analysis (the statistical combination of results from two or more separate studies) of twenty six studies.

You can read more on our blog about how oils with high polyphenols can potentially help with cholesterol levels or Associate Professor of Medicine Mary M. Flynn's report polyphenol containing olive oils and their effects on blood pressure.

The information here is not medical advice, always consult with your doctor for the diagnosis or management of a medical condition.