Sesame Oil

Is It Healthy?

What is sesame oil?

Sesame oil is a vegetable oil, produced by pressing the seeds of the sesame plant which is found in the tropics. Its distinctive nutty and fragrant aroma and taste makes it an essential ingredient in most of the Asian kitchens. Besides being used as a cooking oil, it is also a flavour enhancer in many cuisines. It can be used as a seasoning, a marinade or a dressing. As this oil provides many health benefits, it is also known as “The Queen of Oils”.

Types of sesame oil

The 2 main types of sesame oil are unrefined and refined.

 

Unrefined sesame oil

Can be further categorised into cold-pressed or heat-extracted oil:

 

cold pressed sesame oil

a. Cold-pressed sesame oil is produced by simply crushing sesame seeds at room temperature in an impeller and they are not cooked. This oil is pale yellow in colour, while heat-extracted sesame oil is darker. Besides its mild and nutty flavour, it contains a higher proportion of fatty acids than sesame oil obtained from the heated seeds.

heat extracted sesame oil

b. Heat-extracted sesame oil is available as black and white sesame oil:

i. Black sesame oil is usually dark reddish-brown in colour. It has a very strong flavour and is not commonly used as a daily cooking oil. This oil is mostly used by the Chinese for food therapy or food that enriches the body, for example, sesame oil chicken soup and three cup chicken (San Bei Ji). To make black sesame oil, the black sesame seeds are toasted to 70% to 80% cooked, then molded into chunks and pressed into oil. 

ii. White sesame oil is usually light amber in colour. Its flavour is milder than its black counterpart. This oil is best suited for enhancing the flavour of dishes or added to salad dressings and sauces. To make white sesame oil, the sesame seeds are processed into liquid, then water is boiled and the oil is separated from the seeds.

refined sesame oil

Refined sesame oil

Refined sesame oil has a light colour and a bland flavour. To make this oil, crude sesame oil is neutralised, bleached, deodorised and winterised. It can be used for high-heat cooking like frying. However, many consumers prefer unrefined sesame oil as the refining process removes important nutrients that are originally present in the oil.

Nutrition facts

Fatty Acid Breakdown:

Saturated: 11%
Monounsaturated (e.g. omega-9): 41%
Polyunsaturated (e.g. omega-3, omega-6): 45%

  Omega-3: Omega-6 ratio = 1 : 45 

Benefits

Cold-pressed sesame oil is rich in nutrients and provides a wide range of health benefits:

  • High in antioxidants

Sesame oil is rich in antioxidants sesamin, sesamol and sesaminol which may be significantly beneficial for health1. Antioxidants  neutralise or remove free radicals, which would otherwise lead to inflammation and onset of diseases2. Sesamin is the most abundant lignan in sesame seed, it has shown to help support healthy blood pressure3, reduce cholesterol4, promote vitamin E absorption5 and protect against liver damage6.

 

  • Provide anti-inflammatory effects

Chronic inflammation or long-term inflammation has been linked to a broad range of diseases, such as heart disease, stroke, rheumatoid arthritis and others. Several tests showed that sesame oil helps reduce inflammation including decreasing inflammatory markers7,8,9

 

  • Support heart health

A human trial showed that individuals who consumed 4 tablespoons (~60g) of sesame oil daily for a month had greater reductions in LDL (bad) cholesterol and triglycerides, compared to those who consumed olive oil10. Besides, animal test suggested that this oil may slow the development of plaque in the blood vessels and help prevent heart disease11.

 

  • Support healthy blood sugar

A human trial conducted on adults with type 2 diabetes found that taking sesame oil for 90 days significantly reduced fasting blood sugar and hemoglobin A1c (HbA1c), which is an indicator of long-term blood sugar control12. The higher the HbA1c, the greater the risk of developing diabetes-related complications.

 

  • May support joint health

Several animal tests have associated sesame oil to the improvement of arthritis, one of the most common causes of joint pain, swelling and stiffness13,14,15. Although animal tests have shown that it may provide relief for arthritis, clinical trials are required to confirm its efficacy on human beings. 

 

The drawbacks

  • Imbalanced omega-3 to omega-6 ratio

The omega-3 to omega-6 ratio of sesame oil is 1 : 45, while the ideal ratio is between 2 : 1 and 4 : 1. Most of us are already consuming far too much omega-6 to omega-3 in our daily diet. Excessive omega-6 and insufficient omega-3 may potentially create a pro-inflammatory environment. As an occasional ingredient in Chinese cuisine, this is not something to worry about. Nonetheless, if you  consume large amounts of sesame oil regularly, you are recommended to increase omega-3 rich foods to your diet. Alternatively,  consider using other oils that are high in omega-3s, such as camelina oil and flaxseed oil


  • Unrefined sesame oil cannot withstand high heat

Although unrefined sesame oil retains the beneficial nutrients and natural flavours, it tends to have lower smoke point of 177°C (350°F). Thus, it is best used for raw applications such as dressings and marinades, or low- to medium- heat cooking, but not high-heat cooking such as deep-frying.

 

  • Refined sesame oil lacks nutrients

Refined sesame oil that is completely processed with the use of chemicals and heat has a high smoke point of 210°C  (410°F) and hence, can be used for high-heat cooking such as deep-frying. However, the refined oil is not flavourful and the taste is neutral. Furthermore, the refining process also removes most of the beneficial nutrients present in the oil, making it less nutritious than unrefined oil.

References:

1. J Med Food. 2015 Apr 1; 18(4): 393–402.

2. Oxid Med Cell Longev. 2017; 2017: 8416763.

3. J Nutr Sci Vitaminol (Tokyo).2009 Feb;55(1):87-91.

4. J Agric Food Chem.2015 Mar 25;63(11):2963-9. 

5. Lipids.1995 Jun;30(6):499-505.

6. Ann Nutr Metab 1993;37:218–224

7. Med J Islam Repub Iran. 2018; 32: 98.

8. Springerplus.2013 Dec 7;2:659. 

9. Cureus. 2017 Jul; 9(7): e1438.

10. Int J Prev Med. 2013 Sep; 4(9): 1059–1062.

11. J Med Food. 2015 Apr 1; 18(4): 393–402.

12. J Am Coll Nutr.2019 Mar-Apr;38(3):235-246.

13. Neuro Endocrinol Lett.2009;30 Suppl 1:22-4.

14. Food Nutr Res. 2016; 60: 10.3402/fnr.v60.29807.

15. Evid Based Complement Alternat Med. 2018; 2018: 9365464.