Olive oil is often said to be extremely good for you. Whether it’s the antioxidants, the miracles of the ‘Mediterranean Diet’, or the high monounsaturated fat content, people are always ready to give you reasons for why you should be consuming more olive oil.
Health food bloggers, neo-hippies and the “all-natural” movements that are so prevalent these days all seem to love olive oil. Some are drifting more towards coconut oil, and a small number are now raving about butter coffee (we’ll come to this in a later article). But olive oil still has a very strong reputation in the online health and fitness world.
People not “involved” in the industry will casually talk about olive oil being “healthy”. They stress that they only ever use extra virgin olive oil; not the nasty regular stuff.
But just how “healthy” is olive oil?
Has it been shown to have any positive effects on health, fitness, or longevity?
Is there actually a difference between regular olive oil and extra virgin olive oil?
in this article, we’re going to take a look at the claims made about olive oil and find out if any of them really stand up under scrutiny. We’ll examine the studies that have looked at olive oil consumption and its relationship to health. We will discuss the limitations of these studies; what they tell us and what they don’t. At the end, we’ll give you a summary of our findings and tell you whether or not olive oil deserves its reputation as a “health food”.
Olive Oil Health Benefits
To kick things off, let’s go through some of the benefits of olive oil that seem to be firmly backed by science.
Surprisingly, there is a lot of hard empirical evidence showing that olive oil consumption – or rather extra virgin olive oil consumption – is correlated with a lower risk of cardiovascular disease.
One often talked-about piece of evidence for this is the PREDIMED Study.
In this large scale, long-term clinical trial (ref), researchers examined how olive oil intake affected cardiovascular disease progression in people consuming a Mediterranean diet. They also measured what nut intake did for disease progression, but we’ll ignore those results in this article.
The researchers also looked at the type of olive oil being consumed; they measured total olive oil intake (including EVOO) and extra virgin olive oil intake separately.
Over 7,000 participants took part, and follow-up examinations were conducted after about 5 years.
The results of this study should be enough to surprise anybody: “Participants in the highest energy-adjusted tertile of baseline total olive oil and extra-virgin olive oil consumption had 35% (HR: 0.65; 95% CI: 0.47 to 0.89) and 39% (HR: 0.61; 95% CI: 0.44 to 0.85) cardiovascular disease risk reduction, respectively, compared to the reference. Higher baseline total olive oil consumption was associated with 48% (HR: 0.52; 95% CI: 0.29 to 0.93) reduced risk of cardiovascular mortality.”
That is a significant result.
Lowering the incidence of heart disease by 35% across a group so large is really quite something.
Yet the results get even more impressive and surprising: “For each 10 g/d increase in extra-virgin olive oil consumption, cardiovascular disease and mortality risk decreased by 10% and 7%, respectively.”
That is a positively correlated relationship between extra virgin olive oil consumption and a lower incidence of heart disease. The relationship appeared to be robust and statistically sound.
So for every extra tablespoon of EVOO the people in this study were consuming, their chances of developing cardiovascular disease of any kind decreased by 10%.
Now, some potential explanations need to be highlighted here. First of all, it’s possible that the people consuming more oil were therefore getting fewer calories from other foods – foods high in cholesterol, trans fats, etc. It is also possible that the people consuming more EVOO were also more health-conscious than the other participants; they may have been exercising more often, fasting frequently, getting plenty of sleep, etc.
Things like stress levels and exercise levels weren’t controlled in this trial, so there could be lots of reasons why this correlation exists that have very little to do with EVOO’s heart-protecting properties.
Some academics who reviewed this study chose not to focus on olive oil in particular, but the rough components of the Mediterranean diet as the cause of the reduction in cardiovascular disease: “The PREDIMED study results demonstrate that a high-unsaturated fat and antioxidant-rich dietary pattern such as the MeDiet is a useful tool in the prevention of CVD”.
However, this isn’t the only study to find a positive relationship between EVOO consumption and a reduced risk of heart attack, stroke, etc.
A very recent literature review published in Endocrine, Metabolic and Immune Disorder Drug Targets found that extra-virgin olive oil consumption was probably the biggest factor in explaining why the Mediterranean diet reduced heart disease risk (ref).
The researchers looked at any paper focused on the supplementation of extra virgin olive oil.
Their conclusion is succinct but powerful: “The studies analyzed demonstrated the role of EVOO as anti-inflammatory, antioxidant and vasodilatory nutrient that may contribute to lower the atherosclerotic burden.”
Reduce atherosclerosis and promote vasodilation, and it becomes very difficult for a heart attack to occur. The same can be said about a stroke.
There are plenty of studies out there looking at olive oil consumption and the risk of cardiovascular disease. We advise you to look at the bibliographies of some of the cited papers and do some research of your own before you draw any strong conclusions.
We’ve covered the evidence well enough for our purposes. Now let’s move on to the negative health effects of consuming olive oil.
Negative Health Effects
The first thing we need to say is that oil is incredible energy dense. Consuming seemingly small amounts of oil means consuming a lot of extra calories that you otherwise wouldn’t be eating.
By far and away the biggest predictor of cardiovascular disease is obesity.
A person who is overweight is significantly more likely to develop cardiovascular disease than someone who is a healthy weight for their height and age.
We don’t mean average weight. We mean a healthy weight, as defined by medical science.
If you are truly concerned about reducing your risk of developing heart disease of any sort, then reducing your body weight to within a healthy range is the first step you should take (ref). Your focus should of course be reducing body fat, but for most people, reducing body fat (both subcutaneously and viscerally) means dropping in total body weight (we don’t care what the fitness magazines tell you).
Adding in more oil to your already over-sized diet is not going to significantly reduce your risk of sudden heart attack or stroke.
If anything, it will just exacerbate the problem by making you fatter. This will in turn make you more at risk of having a heart attack or a stroke.
If you’re even slightly overweight and you’re worried about your heart, the best thing you can possibly do is cut the calories and get to a healthy weight for your age and height.
The next most important thing we need to mention is that olive oil is not 100% beneficial to health. Contrary to what many claim, olive oil consumption can also have a damaging effect on health.
Olive oil consumption raises LDL cholesterol levels above baseline.
We know this flies in the face of what so many health bloggers say, but the writing’s on the wall with this one; olive oil raises LDL-C similar to both butter and coconut oil (ref). Butter is significantly worse, of course. But olive oil and coconut oil both raise LDL-C significantly above baseline.
LDL cholesterol is known as the “bad” cholesterol. It is this form of cholesterol which causes fatty plaques to build up in your arteries (atherosclerosis), so it is really this form of cholesterol which causes heart attacks and strokes.
The fact that olive oil consumption raises cholesterol levels is not well known. Many people misrepresent the above cited study to argue that olive oil reduces LDL cholesterol levels. This is true only when compared to butter. Olive oil is better than butter if your goal is keeping LDL-C low. But they both make the problem worse!
This sits well with an interesting study conducted on monkeys. Here, researchers found that a group fed a high mono-unsaturated fat diet (similar to olive oil) developed the same amount of arterial damage as a group fed a high saturated fat diet (similar to butter). The only group to see relatively lower levels of arterial damage was the group with a high poly-unsaturated fat diet (PUFs are found in flax seeds, walnuts, sunflower seeds, etc).
Finally, we come to the big one: coagulation factors.
Coagulation factors are responsible for triggering blood clots. When you get cut, your body produces these coagulation factors, which then initiate platelet clotting at the cut to stop bleeding. They are not in and of themselves dangerous or harmful to health.
Yet these coagulation factors also cause clots in your veins and arteries. These clots are responsible for the vast majority of heart attacks and stroke (up to 90% by rough estimate).
It shouldn’t surprise you to learn that high fat meals spike blood coagulation factor VII (ref). It does’t seem to mater whether you’re eating rapeseed oil, olive oil, sunflower oil, palm oil, or butter; all of these fats spike coagulation factor VII in a very similar manner. This makes blood clots far more likely to occur.
As the researchers in the above cited study stated: “These findings indicate that high-fat meals may be prothrombotic, irrespective of their fatty acid composition. The postprandial FVII activation was not associated with the plasma triglyceride or free fatty acid responses.”
Conclusion – Is Olive Oil Good For You?
Many of the health claims made about olive oil have a basis in science.
However, if you are looking to protect your heart from disease, then simply adding extra olive oi to your diet looks like it is unlikely to help. In fact, it might make things considerably worse.
Olive oil raises LDL-C, and it increases coagulation factor VII levels, making blood clots more likely.
It does seem to reduce heart disease incidence in people eating a Mediterranean diet. However, there could be lots of reasons for this (the combination of EVOO and a high vegetable, high fruit diet, extra sun, etc).
The best way to promote your health is to reduce your body fat levels and consume a more balanced, fiber-rich diet, and to cut the junk food. Very few people eat a genuinely Mediterranean diet, and all of the evidence showing that EVOO protects your heart assumes that the baseline diet is rich in fruits, vegetables, and omega-3 fatty acids.
Olive oil might reduce the risk of heart disease in some people. For most of us, the negatives are likely to balance out the positives.