Peanut Oil

Is it Healthy?

What is peanut oil?

Peanut oil, also known as groundnut oil or arachis oil, is an oil made from the seeds of the peanut plant. This oil is commonly used in Chinese, South Asian and Southeast Asian cooking due to the strong peanut flavour and aroma that it gives. 

Types of peanut oil

cold pressed peanut oil

Cold pressed peanut oil is extracted by crushing the peanut to force out the oil. This low-heat process retains the natural flavour and more nutrients than refined oil. This unrefined oil has a low smoke point of 160°C and hence, not suitable for high-heat cooking such as frying. 

refined peanut oil

Refined peanut oil is oil that has been separated from peanut proteins via mechanical and chemical processes. First, the peanuts are steamed and crushed at high temperatures. The resulting oil is then degummed, neutralised, bleached and deodorised, removing virtually all allergens. It is generally safe for those with peanut allergies. Refined peanut oil has a high smoke point of 232°C so it is suitable for high-heat cooking. It is commonly used by restaurants to fry foods like chicken and French fries.

gourmet peanut oil

Gourmet peanut oil is considered a specialty oil. It is unrefined and usually roasted, giving the oil a deeper and more intense flavour than refined oil. Since this oil is not refined, it retains many of the peanut’s nutrients. This type of oil is commonly used for flavouring rather than cooking. Sometimes, it is added into sauces, dressings, marinades or drizzled over a salad. 

peanut oil blends

Peanut oil blends refer to peanut oil that is blended with a similar tasting but less expensive oil, such as soybean oil to make them more affordable. To maintain excellent frying qualities, it is commonly blended with an oil that has a similarly high smoke point. Peanut oil blends are usually sold in bulks for frying foods. 

Nutrition facts

Fatty Acid Breakdown:

Saturated Fat: 20%
Monounsaturated (e.g. omega-9): 50%
Polyunsaturated (e.g. omega-3, omega-6): 30%

Omega-3: Omega-6 ratio = 1 : 38

Cold pressed peanut oil is higher in nutrients and antioxidants than the refined alternative. 

Benefits

Cold pressed peanut oil offers the following health benefits:

 

  • Provide vitamin E

One tablespoon of peanut oil contains 11% of the recommended daily intake (RDI) of vitamin E. Vitamin E is a powerful antioxidant that protects the body from free radical damage linked to chronic diseases. Vitamin E may help reduce the risk of heart disease, certain cancers, cataracts and even protect against age-related mental decline1,2

 
 
  • May lower blood sugar:

Animal studies suggest that peanut oil may help improve insulin sensitivity and improve blood sugar control in people with diabetes. In the studies, diabetic rats fed a diet fortified with peanut oil showed a significant reduction in blood sugar3

The drawbacks

 

  • Exceptional high omega-6s

Peanut oil is very high in omega-6s and lacks omega-3s, with an omega-6  to omega-3 ratio of 38 : 1. For optimal health, this ratio should be closer to 1 : 1 to 4 : 1. Modern lifestyle diet tends to consist of high omega-6s, its intake has skyrocket over the last few decades, along with increases of inflammatory diseases like cardiovascular disease, obesity, Alzheimer’s and cancer. To have a healthy balanced ratio, intake of peanut oil should be limited. It is recommended to substitute peanut oil with omega-3-rich oils such as flaxseed oil and camelina oil in your daily meals. 

 
 
  • Cold pressed peanut oil is not suitable for high-heat cooking

Cold pressed peanut oil has a low smoke point (160°C), a temperature at which the oil breaks down and burns, resulting in unpleasant burnt taste and the release of harmful free radicals. Cooking it beyond this smoke point is detrimental to your health. This oil is definitely not suitable for high-heat cooking such as frying, which temperatures typically range between 163°C and 190°C. Meanwhile, refined peanut oil has a high smoke point (232°C) and is ideal for cooking at high temperatures. Nonetheless, the refined oil has a neutral taste and is stripped of nutrients. To cook with a nutritious, cold pressed, oil with a high smoke point, you may want to consider camelina oil or camellia oil

 
 
  • May cause allergic reactions

Although refined peanut oil is not a concern for people with peanut allergies since the refining process had markedly decreased the allergens, this is not the case for cold pressed oil. Cold pressed peanut oils are not refined and may contain sufficient peanut allergens to trigger an allergic reaction4. Having said that, it should be noted that refined peanut oil is also stripped of precious nutrients, such as essential fatty acids, antioxidants and vitamins, making it a less healthy option than cold pressed oil. 

References:

 

1. Sultan Qaboos Univ Med J. 2014 May; 14(2): e157–e165.

2. Public Health Nutr.2015 Oct;18(15):2804-14.

3. BMC Nutrition volume 2, Article number: 28 (2016) 

4. J Allergy Clin Immunol volume 93, Article number: 4 (1994)