Is oil good for you?
Plant Foods Contain Fat in their Whole Form
|Food||Quantity||Fat (g)||Total Calories||Fat Calories||Percentage of fat (calories)|
|Brown rice, cooked||1 cup (195g(||1.3g||218||15||6.88%|
|Black beans, cooked||1 cup (173g)||0.9g||227||8||3.52%|
|Chickpeas, canned||1 cup||4.2g||211||38||18%|
|Corn kernel, cooked||1 cup||1.8g||132||16||12.12%|
|Oatmeal, cooked with water||1 cup||3.6%||166||32||19.28%|
|Red kidney beans, cooked||1 cup||0.9g||215||8||3.72%|
|Quinoa||1 cup (185g)||2.5g||160||22||13.75%|
|Chia Seeds||20g (2 tablespoons)||6.6g||77||60||77.92%|
|Peanut butter||1 tablespoon (20g)||10g||125||90||72%|
Oil is Not a Whole Food
Oil is a product that has been extracted from the whole food. When oil Is extracted from the whole food, pretty much all the good stuff is left behind (vitamins, minerals, fibre, protein and carbohydrates). It is no longer a whole food, but a highly processed, calorie dense food with little nutritional value. The fibre, carbohydrates and proteins exist in foods so that we DON’T over-consume fats (we need the fibre etc. there so we don’t eat too many calories!).
Fats are essential in our diet, but we can get plenty from whole plant foods. Vegetable oil is similar to refined sugar. Sugar cane is processed so that all the fibre, and most vitamins and minerals are removed, leaving only the refined sugar that his little nutritional value. The same process occurs with vegetable oils. Almost everyone will tell you that sugar isn’t healthy, yet most people wouldn’t say the same thing about vegetable oils.
Oil is calorie dense
Oil is the most calorie dense food on the planet. One tablespoon (20ml) of olive oil contains 160 calories. This is equivalent to the calories in a 375ml can of coke or a 35g Cherry Ripe chocolate bar. Oil contains 9 calories per gram, compared with carbohydrates and proteins which contain 4 calories per gram, and starches, which contain 1 calorie per gram.
Oil contributes to weight gain
Calorie dense foods cause us to gain weight quickly and easily. Oil is also readily absorbed by the body, much more so than carbohydrates or protein. Our bodies preferred source of energy is carbohydrates, so it will always burn carbohydrates first, while storing the fat in case of famine (sounds weird but it’s just the way we’re wired).
Research (Turner-McGrievy et al 2007) shows that people who follow a low fat (10% of energy) vegan diet lose significantly more weight when compared to those on a moderately low fat diet. This is because of a reduction in energy density due to the low fat content and increased fibre intake.
High Fat Plant Foods
Some whole plant foods contain higher concentrations of fat (nuts, nut butters, seeds, seed butters, olives, avocadoes) and we need to eat these as treats, rather than making them a huge part of our diet. These things are health promoting, but can lead to weight gain (or inability to lose weight) if over-consumed.
What about ‘good’ fats like olive oil?
Olive oil contains mostly omega-9 monounsaturated fats, which are not required by the body (so it is mostly empty calories). Olive oil also contains 15% saturated fat. Olive oil does contain omega-3, an essential fatty acid, but only about 1%. It also contains omega-6, with an omega-6 to omega-3 ratio of 13:1, a much higher ratio than the suggested target of 4:1.
Some people think that it’s the polyphenols in olive oil that makes it healthy. But polyphenols are abundantly available in many plant foods (mostly fruits, vegetables and soy), so it’s not necessary to get them from olive oil. For example, 100g of blueberries contains 218 mg of polyphenols, whereas 1 tablespoon (20 ml) of extra virgin olive oil contains only 12.4mg of polyphenols (Perez-Jimenez et al 2010).
What about the Mediterranean Diet?
The Mediterranean diet is definitely healthier than the standard Western diet, however it’s not because of the olive oil. It’s healthy in spite of the olive oil. A traditional Mediterranean diet was characterised by a high consumption of cereals, legumes, nuts, vegetables, and fruits; moderate to high fish consumption; small to moderate consumption of poultry and dairy products; low consumption of red meats and meat products; and moderate alcohol intake (Estruch 2013).
The benefit of a Mediterranean style diet comes from the high intake of unrefined plant foods. It’s a mostly vegetarian diet.
A research paper published in 2000 states that the Mediterranean diet appears to be beneficial due to the antioxidant rich foods such as vegetables and fruit (Vogel et al 2000). The authors stated that “Dietary fruits, vegetables, and their products appear to provide some protection against the direct impairment in endothelial function produced by high-fat foods, including olive oil.”
The PREDIMED study (Schroder et al 2014) caused headlines for having a substantial reduction in cardiovascular disease. The PREDIMED study showed that those on a Mediterranean diet (supplemented with either nuts or olive oil) reduced their incidence of cardio-vascular disease by about 30% compared to those on a ‘low fat’ control diet. However, when you look at the study details, you find that the ‘low fat’ diet in the study contained 33% fat. This is more fat than the average Australian consumes (ABS 2014). It’s also much more fat than in a diet that can reverse coronary heart disease, which is less than 10% fat (Ornish et al 1998, Silberman et al 2010, Esselstyn et al 2014).
Looking into the details of the PREDIMED study you also find that the Mediterranean diet did not reduce the risk of death. There was no statistical significance in total mortality between the groups. Dr Dean Ornish from the Preventive Medicine Research Institute, sums it up well in his letter to the editor of The New England Journal of Medicine (who published the PREDIMED study). “A Mediterranean diet is better than what most people are consuming; even better is a diet based on whole foods and plants that is low in fat (especially saturated and trans fat) and in refined carbohydrates while allowing for sufficient consumption of n–3 fatty acids” (Kopel et al 2013).
So the Mediterranean diet does reduce heart disease, but it does not eradicate it. A low fat (<10%) whole food plant based diet has been shown to not only reduce heart disease, but prevent and reverse heart disease as well (Ornish et al 1998, Silberman et al 2010, Esselstyn et al 2014).
Essential Fatty Acids
Omega-6 to Omega-3 Ratio
Western diets have excessive amounts of omega-6 fatty acids (Simopoulos 2008). The suggested optimal ratio of omega-6 to omega-3 is 4:1 or less (Patterson et al 2012), yet in Western diets the ratio is between 10:1 and 20:1 (Molendi-Coste 2011). People are eating more omega-6 now than ever before because of the increased intake of saturated fat and vegetable oils rich in omega 6 fatty acids, and also the reduced intake of fibre, fruits and vegetables.
Too much omega-6
The excessive amounts of omega-6 promote the development of many chronic diseases (Simopoulos 2008, Patterson et al 2012, Simonopoulos 2006). Whereas research shows a balanced omega-6 to omega-3 ratio should lead to decreases in cardiovascular disease and other chronic diseases and improve mental health (Simonopoulos 2000).
The average Australian gets 0.6% of total calories from omega-3 fatty acids, which is within the recommended range of 0.5-1%. So the solution to the ratio problem is to reduce the amount of omega-6 fatty acids that people are eating.
The Western diet contains a lot of omega-6 fatty acids, and that is why people are taking in excessive amounts. Researchers suggest reducing Omega-6 fatty acids by avoiding vegetable oils high in omega and also decreasing meat intake (Simonopoulos 2016). A high omega-6/omega-3 ratio is also associated with overweight and obesity, whereas a balanced ratio decreases obesity and weight gain (Simonopoulos, 2016).
Should I take Omega 3 Supplements?
Many people take omega-3 supplements in the form of fish oil. However the research does not show that it offers any benefits or protection. In 2012, researchers (Kwak et al) analysed 14 randomised, double-blind, placebo controlled trials (the gold standard of trials) on the efficacy of omega-3 fatty acid supplements in the secondary prevention of cardiovascular disease. The review involved 20,485 patients with a history of cardiovascular disease. The results showed that supplementation with omega-3 did not reduce the risk of overall cardiovascular events, all-cause mortality, congestive heart failure, or stroke. In fact, they found no significant preventive effect from the supplements.
Another systematic review (Evangelos et al 2012) involving 20 studies and 68,680 patients assessed the role of omega-3 supplementation on major cardiovascular outcomes. The results showed that supplementation was not associated with a lower risk of all-cause mortality, cardiac death, sudden death myocardial infarction or stroke.
Eskimos and Omega-3
In the past it was thought that Eskimos suffered less heart disease due to a high intake of Omega-3. In the 1970s, Danish investigators Dang and Dyerberg had been led to believe that Eskimos had a low prevalence of coronary artery disease despite eating large amounts of animal fat. The investigators described the Eskimo diet as consisting of large amounts of seal and whale blubber. They thought that this provided them with protection. This was the start of many studies of the Eskimo diet over the next 40 years.
In 2014, researchers conducted a systematic review to examine whether morbidity and mortality from cardiovascular disease is lower in Eskimos. The results showed that Greenland Eskimos and Canadian and Alaskan Inuit suffer just as much coronary artery disease as other populations (Fodor et al 2014). The review also found that the overall mortality of Eskimos is twice as high as that of non-Eskimo populations. Also, their life expectancy is about 10 years shorter than the Danish population. Clearly all that omega-3 was not protective for the Eskimos.
Bang and Dyerberg’s studies from the 1970s are often cited as ‘proof’ of low prevalence of CAD in Eskimos. However, the Danish investigators did not study the prevalence of CAD. Their research focused on the dietary habits of Eskimos. It offered only speculation that high intake of marine fats had a protective effect on coronary arteries (Fodor et al 2014).
Omega-3 Supplements not necessary
The solution to getting enough omega-3 is to consume less omega 6. Decreasing your intake of omega 6 will automatically allow your ratio of omega-6 to omega-3 to decrease.
Oil Damages Blood Vessels
What happens to your blood vessels when you eat oil and other high fat foods?
Researchers (Vogel et al 1997) compared the blood vessels of participants eating two different breakfasts. Each breakfast consisted of 900 calories each. One group ate a high fat (50g fat) McDonald’s breakfast. The other group ate a low fat cereal and fruit breakfast. Within just one hour of eating the high fat meal, arteries stiffened, reducing in diameter, and stayed that way for 6 hours. None of this occurred in the group eating the cereal based breakfast.
Does oil have the same effect on arteries as a McDonald’s breakfast?
In a study published in Clinical Cardiology (Vogel 1999), researchers tested the effect of olive oil, a fast food breakfast, cheesecake and a hamburger and fries on participants’ blood flow. The results showed that olive oil impairs endothelial function just as much as the other high fat meals.
In another study published in 2000 (Vogel et al), researchers compared the blood flow of participants after being fed a meal of either olive oil, canola oil or salmon. The results showed that the meal with olive oil reduced blood flow in the body by 30%.
Oil impairs endothelial function
This reduction in blood flowfrom oil and high fat meals impairs the endothelium, the inner most lining of your arteries.
The endothelium is the body’s largest endocrine organ. If it was laid out flat, it would cover two tennis courts. One of the most important endothelial functions is to maintain the structure and tone of our veins (Vogel 1999). Endothelial dysfunction has been identified as an early sign of atherosclerosis (Vogel 1999).
Other oils have also been shown to impair endothelial function. In a study published in 2007 (Reuda-Clausen et al), researchers looked at the effect of olive oil, soybean oil and palm oil on arterial blood flow. They used both fresh and deep fried versions of each oil. After the meals, the results showed that all three types of oil impaired endothelial function by around 32%.