Interesterified soybean oil (ISO) is a type of fat created through a process called interesterification. This process involves rearranging the fatty acids in triglycerides, which are the main components of dietary fats. By changing the positions of these fatty acids, manufacturers can modify the oil's physical properties, such as its melting point and texture, without increasing the saturated fat content. This makes ISO an attractive alternative to partially hydrogenated oils that contain harmful trans fats.

Interesterification can be achieved through two primary methods: chemical and enzymatic. Chemical interesterification randomly swaps fatty acids between triglycerides, while enzymatic interesterification can direct the swapping process to specific positions on the glycerol backbone. This results in a fat that can mimic the desirable properties of solid fats while reducing the overall saturated fat content by approximately 10% compared to non-interesterified fats (Berry, 2009).

The food industry has increasingly adopted interesterified fats as a substitute for trans fats, which have been linked to various health issues, including cardiovascular disease (CVD). Interesterified soybean oil is commonly found in products like margarine, baked goods, and snacks due to its ability to enhance texture, stability, and shelf life (Center for Science in the Public Interest).

Improved Texture: ISO can provide the desired creaminess and spreadability in food products without the negative health implications associated with trans fats.
Shelf Stability: Foods containing ISO tend to have a longer shelf life due to the oil's modified properties.
Reduced Saturated Fat: By replacing saturated fats with ISO, manufacturers can create products that align better with dietary guidelines recommending lower saturated fat intake (Department of Health, 1991).

Despite its advantages, there are ongoing concerns about the health effects of consuming interesterified fats. Research indicates that ISO may negatively impact metabolic health, leading to weight gain and impaired glucose tolerance in animal studies (Miyamoto et al., 2018). This raises questions about its long-term effects on human health, particularly in relation to cardiovascular risks.

Metabolic Effects: Studies have shown that diets high in ISO can lead to increased body mass and impaired glucose metabolism, suggesting potential risks for metabolic syndrome (Miyamoto et al., 2018).
Cardiovascular Health: The exact impact of ISO on cardiovascular health remains unclear, with some studies indicating it may not be as harmful as trans fats, while others suggest it could still pose risks (Berry, 2009).

Interesterified soybean oil represents a significant advancement in food manufacturing, offering a functional alternative to trans fats. However, the potential health implications of its consumption are still being researched. As evidence continues to emerge, it is crucial for consumers to stay informed and for policymakers to consider these findings when developing dietary guidelines.

Miyamoto, J. É., et al. (2018). Interesterified soybean oil promotes weight gain, impaired glucose. Journal of Nutritional Biochemistry, 59, 153-159. Link
Center for Science in the Public Interest. (n.d.). Inter-esterified oil. Link
Berry, S. (2009). What are interesterified fats and should we be worried about them in food? Link