Olive Oil and Cancer Cancer is a common cause of death, characterized by uncontrolled growth of cells in the body. Studies have shown that people in the Mediterranean countries have a fairly low risk of cancer and some have speculated that olive oil has something to do with it . One potential contributor to cancer is oxidative damage due to free radicals, but extra virgin olive oil is high in antioxidants that reduce oxidative damage . The oleic acid in olive oil is also highly resistant to oxidation and has been shown to have beneficial effects on genes linked to cancer .
Many studies in test tubes have shown that compounds in olive oil can help fight cancer at the molecular level . Whether olive oil actually helps prevent cancer has yet to be studied in human controlled trials.
Olive Oil and Alzheimer's Disease Alzheimer's disease is the world's most common neurodegenerative disease and a leading cause of dementia. One feature of Alzheimer's is a buildup of protein tangles called beta amyloid plaques, in certain neurons in the brain. A study in mice showed that a substance in olive oil can help to clear these plaques from the brain . A human controlled trial showed that a mediterranean diet enriched with olive oil had favorable effects on brain function and reduced the risk of cognitive impairment .
There is preliminary evidence that olive oil can help fight cancer and Alzheimer's disease, although this needs to be confirmed in human controlled trials.
Can You Cook With it? During cooking, fatty acids can oxidize. That is, they react with oxygen and become damaged. It is mostly the double bonds in the fatty acid molecules that are responsible for this. For this reason, saturated fats (no double bonds) are resistant to high heat, while polyunsaturated fats (many double bonds) are sensitive and become damaged. It turns out that olive oil, which contains mostly monounsaturated fatty acids (only one double bond), is actually fairly resistant to high heat. In one study, researchers heated extra virgin olive oil to 180 degrees Celsius (356 degrees Fahrenheit) for 36 hours. The oil was highly resistant to damage . Another study used olive oil for deep frying, and it took 24-27 hours for it to reach damage levels that were deemed harmful . Overall, olive oil seems to be very safe... even for cooking at a fairly high heat.
Take Home Message
Olive oil is super healthy. For people with heart disease or at a high risk of getting it in the future, olive oil is most definitely a "superfood." However... it is extremely important to get the right stuff. That is, extra virgin olive oil that hasn't been diluted with cheaper oils. The benefits of this wonderful fat are among the few things that most people in nutrition actually agree on. Now that's something you don't see often.