Opinion is divided on the health benefits of dietary fat, but experts can all agree that olive oil is good for you. As a celebrated ingredient of the Mediterranean diet, olive oil benefits everything from heart health to weight management, and ongoing scientific research continues to reveal more of its many hidden health assets.
Dr Louise Wiseman explores why olive oil is an invaluable kitchen cupboard staple and whether it should also earn a place on your beauty shelf, with 14 health benefits of olive oil supported by scientific research:
What is olive oil?
Olive oil is the oil obtained from the fruit of the olive tree (olea europaea L). It contains fatty acids and up to 230 other compounds in very small quantities. These include polyphenol compounds which act as antioxidants in the human body. Antioxidants are great because they undo the damage caused to cells by ageing, stress and daily life and they also work against inflammation.
Is olive oil good for you?
There are a number of reasons why olive oil is good for the human body. There is increasing evidence of a strong role in preventing chronic diseases and this makes both researchers and consumers incredibly excited. However, the type of oil used and preparation methods are very important.
Olive oil and the importance of dietary fat
We need healthy fats for many processes in the body – not least our hormones and central nervous system. Fat is a source of essential fatty acids and the body cannot make these itself. Fat in the diet helps us absorb the fat soluble vitamins A, D, E and K.
About a tenth of olive oil is polyunsaturated fat (such as omega 3 and 6) and a little more is saturated. Most of the fat in olive oil is actually healthy monounsaturated fatty acids (MUFAs). The primary MUFA in olive oil is oleic acid. MUFAs are far better for health than saturated or trans fats.
It is tempting after reading about the health benefits to pour extra virgin olive oil over everything. However, any fat is still highly calorific, so even olive oil should not be consumed in excess. Most of the studies on humans have seen benefits from as little as a teaspoon a day, so moderation is key.
Which type of olive oil is best?
The value of olive oil comes from its nutrients – namely Vitamins such as E and K, Omega 3 fatty acids and antioxidants. The production method will affect how much of these make it from the olive to the plate.
Non-virgin or regular olive oil is a blend of cold-pressed and processed oils and will have been cleaned by heat or chemical, so the nutrient content is reduced. For example, the polyphenols found in olive oil are destroyed in this process.
Virgin olive oil is the oil obtained by mechanical or physical means only (eg grinding olives into a paste then pressing them). The oil is not heated or altered or chemicals added. The oil has a higher content of nutrients and a purer cleaner flavour. Virgin olive oil is from the second pressing of the olives.
The first press of the olives is called extra virgin olive oil; otherwise it's made similarly to virgin olive oil. Extra virgin oil may have a fruity flavour and an even higher nutrient content.
What about heat and oil?
For cooking, olive oil has a relatively lower smoke point compared to other oils so is best for low and medium heat cooking. Once you get above an oil’s smoke point the oil burns and smokes and harms the flavour as nutrients degrade. Harmful free radicals can also be released. In a similar way it is wise to keep olive oil in a dark bottle in a cool dark cupboard or pantry and not next to a warm stove.
12 proven health benefits of olive oil
Olive oil comes with a number of proven health benefits, backed by scientific research:
Recent research has shown that olive oil consumption is linked to living longer. The Mediterranean diet contains a higher proportion of fat than many other healthy diets but up to two thirds of the vegetable fat in this diet is from olive oil.
World respected studies including the Seven Countries Study and the MONICA study showed that Mediterranean countries had lower incidence of coronary heart disease and death than the USA or other European areas. This could have been due to other factors of the Mediterranean diet, which is also rich in vegetables and fruit, but more recent studies have looked independently at olive oil and and suggest high consumption of the oil may reduce mortality by a quarter.
2. Cancer fighting properties
Studies have shown some components of olive oil may prevent development and progression of cancer, due to many mechanisms including the antioxidant effect. In other words, reducing the effect of stress and everyday damage on DNA and the cells. Oleic acid is thought to reduce inflammation and may affect genes linked to cancer. However, a lot of this initial research was done in the lab so more human research is needed.
The most promising research suggests protection against breast and digestive tract cancers, but much of this is on population studies. We need more randomised controlled studies to see if olive oil has a direct effect. Many of the studies show non-significant effects – this means statistically it is not at a level to definitely make a strong conclusion.
3. Reduced blood pressure
Polyphenols are one of the most valuable ingredients of olive oil. A new study suggests regular consumption of extra virgin olive oil can reduce the systolic blood pressure or top number of blood pressure. This is the number that naturally rises with age as the arteries stiffen up. It is historically thought that polyphenols help improve the function of the endothelium, which is the lining of the blood vessels and heart. These results occurred in extra virgin olive oil only, with its assumed higher polyphenol content.
4. Lowers 'bad' cholesterol
Because oleic acid is a MUFA it can promote an improved cholesterol profile compared to a diet rich in saturated fat. MUFAs can lower total cholesterol and also lower the unhealthier portion of cholesterol. The cholesterol-lowering effects of olive oil are even greater if you opt for extra-virgin olive oil, which means the oil is less processed and contains more heart-healthy antioxidants.
5. Promotes heart health
Olive oil may be protective against stroke and cardiovascular disease and the effect can be even stronger in virgin olive oil. Olive oil has been demonstrated to reduce the chance of cardiovascular disease events – like heart attacks and strokes. Experimental studies have also shown it has an antithrombotic or clot-reducing effect. The PREDIMED trial showed extra virgin olive oil and nuts as sources of good fats produced a reduction of cardiovascular events by a third after five years consumption! These results are important within the context of a healthy Mediterranean diet. Olive oil is not going to help you as much if you otherwise eat poorly and smoke.
6. Diabetes reduction
The Mediterranean diet has been shown to reduce the chance of becoming diabetic and olive oil is one of the key components. The PREDIMED trial showed a Mediterranean diet with extra virgin olive oil had up to a 40 per cent reduction in Diabetes compared to controls and that glucose metabolism was generally improved and weight reduced. There is evidence that olive oil containing diets can be a good alternative to low fat diets for some diabetics.
7. Weight management
Studies to address whether olive oil as a fat would encourage obesity have shown that in the context of the Mediterranean diet it can actually help curb obesity.
8. Helps fight dementia
The Mediterranean diet is known to lower the risk of dementia but the extra virgin olive oil may be the real golden key. It may reduce the formation of beta amyloid plaques and tangles within the brain that cause Alzheimers, thus protecting memory.
9. Preserves thought processing and cognition
Alongside protecting against Alzheimers, studies suggest that olive oil consumption could improve thought processing. A Spanish study showed that Extra virgin olive oil or nuts actually improved cognition after 6.5 years compared to a low fat diet. This goes to show how healthy fats really are essential.
10. Helps fight inflammation
The antioxidant component of olive oil is the phenols and thus give an anti-inflammatory effect when included in a diet regularly. Studies have shown inflammatory markers are reduced by olive oil even when consumed in small amounts such as a teaspoon a day; the potential for this is being studied with regards to joint and bowel conditions where reducing inflammation is key. Various studies in animals have shown that olive oil polyphenols (such as oleocanthal and hydroxytyrosol) also work as antioxidants and antinflammatories in the neurological system and in this way there may help protect the brain.
11. Olive oil for wound healing
The fatty acids found in olive oil are said to reduce inflammation, which may help to speed up the wound healing stages. However, olive oil should never be directly applied to the affected area; the recovery process occurs through ingestion. In animal studies olive oil has helped healing through dermal reconstruction and reducing oxidative damage, but more human research is needed.
12. Olive oil for hair
There is not a great deal of scientific research into olive oil and hair. The theoretical value for hair protection would be the ability of the oil to repel water and prevent drying – in this context saturated and monounsaturated oils diffuse into hair much easier than polyunsaturated, so olive oil is a great contender. By preventing water from moving out of the hair olive oil could be considered moisturising.
There is not enough evidence to support olive oil and hair growth, but in protecting hair it might grow longer before it breaks off. However, you might find it too heavy and greasy to be practical as a hair product on a regular basis.
Last updated: 08-03-2021
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