Tuesday, 23 August 2016

Dangers of cooking oils

 Our daily meal often contains some form of fried food. Many of us are aware that fried food has high fat content but it is very difficult for us to get rid of. Will using different cooking oil makes fried food less harmful? 

Before going into the details of cooking oils, here is a brief overview on types of fats which are the main components of oil. There are three main types of fats; monounsaturated(MUFA), Polyunsaturated (PUFA), Trans fat saturated fatty acid. 

Scientists have found that using monounsaturated fat in our cooking reduces triglycerides in our blood while improving the level of HDL aka “good cholesterols”. 

Does that mean we can be healthier by using oil rich in monounsaturated fatty acids? We looked at 3 commonly used cooking oil focusing on the benefits and harms of each. 

Olive oil

Olive oil is obtained from the olive seeds and used heavily in Mediterranean diet. Apart from containing Vitamin E and K, it has 73% monounsaturated fatty acid. It is commonly used for cooking as well as salad dressing. 

One important thing to remember is that, when we heat the oil beyond its smoking point, harmful substances such as aldehydes will form. Aldehydes are known to cause cancer and is normally produced by vegetable oil when it reaches its smoking point.

Fortunately, olive oil has a moderately high smoking point, around 216 Celsius. For high temperature cooking, such as frying olive oil will reach its smoking point but since it contains mostly monounsaturated fatty acid, aldehydes production is minimal. 

Pro: Healthy, contains monounsaturated fatty acid, produces minimal aldehydes
Cons: Expensive

Sunflower oil

There are three types of sunflower oil in the market currently. All three have different processing methods and have different nutrient content. The standard sunflower oil is rich in polyunsaturated fat, while the high oleic version contains 82% monounsaturated fatty acid making it comparable with olive oil. 

Sunflower oil has approximately the same smoking point, around 227 degree Celsius, but since it contains mainly polyunsaturated fat (in the standard version), it is very unstable and produces aldehyde quickly and in higher percentage compared to olive oil. 

Sunflower oil also contains higher Omega 6 (a type of polyunsaturated fat) level, compared to Omega 3. While Omega 3 is known to reduce inflammation in body and helping in reducing heart attacks, omega 6 is pro-inflammatory. Omega 6 has the potential to increase heart diseases, and other inflammatory problems such as rheumatoid arthritis. The ratio of Omega 6: Omega 3 in sunflower oil is 40:1 which is not healthy. 

Even though theoretically this should increase inflammatory conditions, till date there is no enough evidence to prove that. 

Pro: Has omega 3, cheap
Cons: Mostly polyunsaturated fat, and Omega 6. High aldehyde production on cooking. Possibly pro-inflammatory.

Palm Oil

Palm oil is the mostly used cooking oil, especially in the Asian households. Palm oil has been linked with health risks as well as environmental risks. 


There are some strong evidences suggesting palm oil increases the risk of heart problems. For example in a research done in Costa Rica, scientists found that people consuming palm oil are more likely to develop heart attack compared to those consuming other types of oil. Another group of scientists from Singapore concluded that palm oil increases LDL cholesterol by 0.24mmol/l after looking at various researches done on this matter.

This bad effect of palm oil can be explained by presence of almost 50% of saturated fat which is proven to be harmful for our health. 

Palm oil consumption is also said to be harmful to the environment. According to a group of activists, over 300,000 different animals are found in Borneo, and Sumatra and many of them are injured, killed or displaced because of deforestation. Deforestation is done to clear the forest for palm oil plantations. According to the World Wildlife Fund, an area the equivalent size of 300 football fields of rainforest is cleared each hour to make way for palm oil production. Read more on this from here. 

Pro: Cheap, widely available

Cons : Increases risk of heart attack, leads to deforestation 


Among the available cooking oil, olive oil seems to be the best. Choose refined olive oil for deep frying as it has higher smoking point compared to extra virgin olive oil which is more suitable for shallow frying or salad dressing. 

For further reading:

Palm Oil& Environment : http://www.saynotopalmoil.com/Whats_the_issue.php

Sunday, 14 August 2016

Benefits of Fish Oil

Fish oil capsules are widely available in the market these days. Most of it contain omega 3 such as DHA and EPA. Small fish are used to produce the fish oils and omega 3 is a type of fatty acid that is found in it. DHA and EPA are two types of Omega 3 that’s found in marine animals such as fish. Many researches are being done on benefits of fish oil.



Omega 3 is widely believed to have beneficial effects on heart. Heart attacks normally happen in people with hardened blood vessels of the heart (atherosclerosis). Blood cholesterol plays an important role in this hardening process. Thus reducing blood cholesterol level should reduce the hardening process of the blood vessels. 

There are some evidence to suggest omega 3 helps in reducing the blood cholesterol level, especially triglyceride. Triglyceride is a type of cholesterol in our blood, LDL and HDL being the other two. A group of scientists from University of Kansas did a research on this issue. They looked at all the research done on this matter from 2005 to 2015. After looking at all the results, they concluded that omega 3 oil will reduce the level triglyceride if taken 4 g per day. 

Omega 3 also seems to have anti-inflammatory properties. Inflammation is also a key role in hardening of blood vessels, so by reducing inflammation the hardening process should be dampened.
Thus theoretically taking omega 3 fish oils should help protect the heart. But does it?

Cochrane reviewers who are experts in looking for the best evidence searched researches that were done to prove benefits of fish oil in heart health. 

They concluded that “There is not enough evidence to say that people should stop taking rich sources of omega 3 fats”. It’s not clear if omega 3 helps in reducing heart attacks or deaths related to heart problems. 

More high quality evidence is needed to strongly say omega 3 helps in cardiovascular health.

Dry Eyes

Among those who are working on computers most of the time, dry eye is a very common problem. Dry eye is caused by two important groups of diseases. Our tears have two components; water and fat (lipid). One group of disease causing dry eyes is due to tear glands not producing enough water component in the tears, and another group is due to the glands not producing enough fat component. The diseases that are due to lack of fat component in tears are called evaporative dry eyes, and is the commonest cause of dry eyes.

This research done by eye surgeons from Ohio Medical Centre looked at 105 patients with evaporative dry eyes and how they benefit from omega 3 oil. After 12 weeks of supplementing patients with re-esterized omega 3, they saw benefits in the patients’ dry eyes symptoms. But this research was done using re-esterized omega 3 oil. 

Omega 3 that is available commercially comes in two forms; as ester or triglycerides. Ester forms are not so common everywhere with most brands use triglyceride form of omega 3. So does the triglyceride form of Omega 3 helps in reducing dry eyes symptoms as well? 

According to a research done by Indian scientists, after taking 600mg of omega 3 oils (2 capsules per day of normal fish oil capsules), most patients had improvement of their dry eyes problems. This research was done mainly on those who use computers for more than 3 hours per day. They concluded that taking 2 capsules of fish oil per day with a total of 600mg DHA and EPA will cause improvement in dry eyes symptoms after 3 months. 

Another group of scientists repeated this in contact lens wearers. They chose 496 contact lens wearers, and looked at how omega 3 containing fish oil supplement twice a day helps in dry eye symptoms. After 6 months of supplement, patients’ symptoms were under control, and lens wear comfort level also improved significantly.

Mental Health


Dementia is a problem that commonly affects elderly people. It is a disorder of memory, behavior and functioning. There are many causes of dementia, commonest being vascular dementia and Alzheimer’s dementia.

Omega 3 oil has been suggested to protect people from dementia, especially Alzheimer’s disease. Many researches appear to support this fact, but the evidence they offer isn’t strong. Cochrane group of researchers did two different study on this matter.

In one research, they concluded that supplementation of omega 3 oil for patients with Alzheimer’s disease do not improve their mental function, nor reduce depression in them. Another Cochrane review tried to find if omega 3 can be used to prevent onset of dementia.

They concluded that there is no evidence to say omega 3 helps in prevention of dementia. 

Natural food rich in Omega 3 


Do we have to consume omega 3 capsules to get the benefit of it? No, there are plenty natural sources of omega 3. 

There are three main types of Omega 3. ALA, EPA and DHA. Most fish oil capsules contain EPA and DHA and many studies that check the benefits of omega 3 focus on these two types of fat.

EPA and DHA are animal source of Omega 3, thus it’s rich in animals such as fish. Anchovies, and Salmon have some of the highest amount of omega 3 in them. Caviar also has high omega 3 content, especially EPA and DHA. Steaming or cooking the fish does not seem to affect the level of omega 3. 

For further reading

Heart and Omega 3

Cochrane Review on Fish Oil 

Dry eyes and omega 3

Difference between esterized omega 3 vs triglyceride

Dry Eyes among computer user
Dry eyes among contact lens user

Dementia and Omega 3

Dementia Prevention and Omega 3