Soybean Oil

Is It Healthy?

What is soybean oil?

Soybean oil is a vegetable oil that is extracted from whole soybeans. Refined soybean oil is one of the most widely consumed cooking oils in the world. This oil has light flavour and almost no odour. Hence, the flavours of other food in the recipe tend to be more prominent. Soybean oil is widely used in the food industry for products such as mayonnaise, coffee creamers, margarine, sandwich spreads and salad dressings. 

Types of soybean oil

Most soybean oils are refined, blended and sometimes hydrogenated. Unlike extra virgin olive oil, soybean oil is rarely cold pressed.

cold pressed soybean oil

 

Cold pressed soybean oil is extracted from soybeans by using mechanical friction. In the manufacturing processes, no chemicals are used and the oil is left in its virgin form. This process retains most of its original nutrients, including fatty acids, vitamins etc. It has a low smoke point (160°C) and is not suitable for high-heat cooking. 

 

refined soybean oil

 

Refined soybean oil is extracted from soybeans through several industrial refining processes. It is hard to squeeze oil out of soybeans and thus, soybean oil production involves heat, chemical solvents, bleaching and deodorizers. Hence, the finished product is also known as a ‘refined, bleached, and deodorized’ oil. Refined soybean oil has a high smoke point of 232°C and can be used for high-heat cooking. It won’t fill your kitchen with smoke when you are frying at high temperatures. 

 

During the refining process, chemical treatments at the different stages deteriorate the nutrient contents, this includes fatty acids, vitamins, etc. Chemical preservatives are then added to the oil. Refined soybean oil is colourless, odourless and devoid of nutrients and flavours.

How soybean oil is made?

Refined soybean oil is the most consumed oil these days. Refining soybean oil is a complicated process with many stages. The process involves:

soybean oil making - step 1
soybean oil making - step 2
soybean oil making - step 3
making - step 4

Nutrition facts

Fatty Acid Breakdown:

Saturated: 15%
Monounsaturated (e.g. omega-9): 24%
Polyunsaturated (e.g. omega-3, omega-6): 61%

   Omega-3: Omega-6 ratio = 1 : 7

Refined soybean oil has significantly low amounts of natural nutrients and antioxidants than cold pressed soybean oil.

Benefits

Cold pressed soybean oil provides the following health benefits:

  • Provide omega-3 fatty acids

Omega-3 fatty acids, which make up around 7% of the total fatty acid content in soybean oil, has numerous health benefits. Omega-3s are scientifically proven to promote brain health, support healthy vision, fight inflammation, promote healthy cholesterol levels, support healthy skin and others1

 

  • Support cardiovascular health

Soybean oil could significantly reduce the risk of atherosclerosis and cardiovascular diseases, such as heart attack and stroke2. It has been shown to increase HDL (good) cholesterol and decrease LDL (bad) cholesterol levels3. Furthermore, the plant sterols in soybean oil could also help support healthy blood lipid profile. 

 

  • Support bone health

Soybean oil is a good source of vitamin K, with each tablespoon providing 25 mcg of vitamin K, equivalent to 21% DV (Daily Value)4. Vitamin K is an essential nutrient which works synergistically with calcium to support strong bones. Higher blood levels of vitamin K are often associated with higher bone density. Hence, it is recommended to switch to soybean oil if you want to reduce the risk of osteoporosis, which is often a natural result of the ageing process. 

 

The drawbacks

  • High in omega-6s

Although omega-6 fats are vital for health, the modern Western diet contains far more omega-6 fatty acids than required by the body. The recommended omega-6 to omega-3 ratio in the diet is 4:1 or less. Soybean oil, however, contains a much higher ratio of 7:1. Excessive amounts of omega-6s promote inflammation and the development of many diseases, such as heart disease, cancer, etc; whereas increased levels of omega-3s exert suppressive effects. Hence,  you can do to reduce your omega-6 intake simply by avoiding vegetable oils such as soybean oil which is high in omega-6s. Instead, choose to replace with oils which are high in omega-3s, such as flaxseed oil and camelina oil in your daily cooking. 

 

  • Refined oil is bad for health

Most of the soybean oils are refined oils. The process of making refined oils is a highly intensive mechanical and chemical process, which involves the use of toxic chemicals. Consuming these oils can elevate your body’s inflammation, raise blood triglycerides and aggravate an impaired insulin response. The use of these oils has been linked to diabetes, cancer and heart disease in multiple studies. To make matters worse, many refined vegetable oils are also hydrogenated. This hydrogenation process further damages the fatty acids in the oils, and creating trans fatty acids which are very harmful to health. 

Although cold pressed soybean oils are far healthier than refined oils, they have low smoke points (160°C) and hence, are not suited for high-heat cooking such as frying. The cold pressed oils are only good for drizzling, served as a salad dressings and for low-temperature cooking, such as steaming and simmering. 

 

  • Result in more obesity and diabetes than sugar

A study shows that soybean oil causes more obesity and diabetes than a diet high in fructose, a type of simple sugar that makes up 50% of table sugar. Mice on high soybean oil diet showed greater signs of metabolic syndrome such as increased weight gain, larger fat deposits, fatty liver with signs of injury, diabetes and insulin resistance compared to the mice on high fructose diet. Furthermore, the mice on the soybean oil diet gained almost 9% more weight than the mice on the fructose diet5

 

  • GM soybean oil may be harmful for the liver

Genetically modified (GM) soybean oil made from seeds of GM soybean plants was claimed to be healthier than conventional soybean oil. Although it induces lesser insulin resistance (the inability to use hormone insulin efficiently) than conventional soybean oil, study found that it is just as unhealthy as regular soybean oil. It also induces obesity, diabetes and fatty liver6