Oilve oil good or bad?
Updated: Nov 24, 2019
This debate opens a can of worms. We seem to have groups of scientists and health care professionals on both sides and you can see why given the conflicting information that has come out of different studies.
One thing worth noting before we look at the studies is that the quality of the olive oil can have a big role to play in the debate. Dr David L Katz pointed out in the “Stunning secret of olive oil (and cherries)”, the difference between olive oil and oleocanthal rich olive oil (OROO). OROO comes from highly concentrated oleoannthal, which has anti inflammatory and possibly analgesic benefit. On the other hand, standard olive oil may not contain nearly as much oleocanthal, therefore you won’t be able to obtain the benefit like OROO.
Most of the key studies focus on the Mediterranean diet, where olive oil is consumed in high quantities within these areas. The belief was that olive oil consumption increases HDL and lowers LDL; “In Ikaria, we found that for middle-aged people, about six tablespoons of olive oil daily seemed to cut the risk of dying in half”. However, whilst they did have a high olive oil intake, they also had a diet rich in whole plant foods such as fruits, vegetables, whole grains and legumes. So whilst the olive oil could be a factor, their general diet and lifestyle (lots of local seasonal produce and sunshine) is also a potential reason for their lower mortality rates.
The British Heart Foundation also published an article suggesting that “Olive oil could cut risk of heart disease”. Their statement was also based on Mediterranean diet studies and the prevention of cardio vascular disease. Again, this is based on the Mediterranean diet where other factors could be of significance.
Other studies try to focus more on the science e.g African monkey studies “Compared With Dietary Monounsaturated and Saturated Fat, Polyunsaturated Fat Protects African Green Monkeys From Coronary Artery Atherosclerosis” where scientists fed monounsaturated, polyunsaturated and saturated fats to monkeys and they developed similar amounts of coronary artery atherosclerosis, but monkeys fed on poly was less. Given monounsaturated fat potentially has a similar effect to saturated fat, this could point us towards believing that olive oil(Monounsaturated fat) would produce the same result - the problem is that they were not fed olive oil so it could be seen as not conclusive.
A study from 2005 “Olive, soybean and palm oils intake have a similar acute detrimental effect over the endothelial function in healthy young subjects”. This study suggests that all three plant oils increase the triglyceride plasma levels in healthy subjects. The issue here is we do not know the quality of the different oils consumed (extra virgin olive oil or not).
The scientific studies point me back to Dr David L Katz, who was quite right to point it out that that you cannot say olive oil is bad for health without knowing which olive oil is being consumed in the study or the quality of the olive oil.
Bottom line is it’s very difficult to settle on either side the olive oil is it good or bad controversy, there are so many other factors to consider as highlighted above. Compared to saturated fat, monounsaturated fat (olive oil) is less damaging on our health and includes some good antioxidants. This doesn’t necessarily mean olive oil is good for us, as Dr. Caldwell Esselstyn points out; “Between 14 and 17 percent of olive oil is saturated, artery-clogging fat”.
My conclusion is that in general, olive oil used in moderation may be ok but based on the studies I don’t think we can safely say it has significant benefits. For people with heart disease, I would say it should definitely be reduced as much as possible - there are too many studies portraying the negative impact on coronary artery atherosclerosis.
For healthy people thriving on a well balanced, mainly whole food plant based diet where saturated fat intake is relatively low, a small amount of good quality extra virgin olive oil probably won’t do much harm. With that being said, I don’t see enough proof of the benefits so I think limiting it or using it in moderation is key.