Soybean oil can make important contributions to the health of Americans
by Mark Messina, PhD, MS
Health Attributes of Soybean Oil and Its Contribution to US Diets
Soybean oil is the most widely produced vegetable oil in the United States. In 2014, over 20.6 billion pounds were produced with 1.9 billion pounds exported to more than 50 countries. It is also the most commonly consumed oil in American diets accounting for more than half of all US vegetable oil consumption and for a little over 7% of total caloric intake.1 Because soybean oil is nearly always marketed and labeled as vegetable oil, most consumers don’t recognize the extent to which it plays in a role in their diets.
The reason for this labeling approach isn’t entirely known. One theory is that it is linked to the introduction of “all vegetable” shortenings in the 1960s which successfully replaced lard and beef tallow-based shortenings and were largely soybean oil-based. “All vegetable” cooking oils soon followed in the marketplace.
Given the contribution that soybean oil makes to caloric intake, it is important to have an understanding of how it impacts the health and nutrition status of Americans. This is especially relevant given the impact of different dietary fats on coronary heart disease risk.
Fatty Acid Composition of Soybean Oil
Soybean oil is low in saturated fat which comprises about 12% of total fatty acids. About 29% of the fat in soybean oil is monounsaturated. Like sunflower, sesame, and corn oils, soybean oil is rich in polyunsaturated fats (PUFAs) which make up 59% of its total fat content.2 What sets soybean oil apart from these other oils is that the polyunsaturated fat is comprised of both linoleic acid and alpha-linolenic acid. Both of these fatty acids are essential nutrients. Linoleic acid is the essential omega-6 fatty acid while alpha-linolenic acid is an essential omega-3 fatty acid.
This is a unique aspect of soybean oil since most other oils that are rich in PUFAs contain only omega-6 fats and have only negligible amounts of omega-3 fats. Because of its widespread use, soybean oil accounts for over 40% of the US intake of both of the essential fatty acids.1
The omega-3 fat found in soybean oil is not the same as the long chain omega-3 fats that are found in fatty fish. Although these long chain fats have been linked to lower risk for heart disease, they are not considered essential. In part, this is because the body can synthesize them from alpha-linolenic acid, the omega-3 fat that is present in soybean oil.
Effects of Polyunsaturated Fat on LDL-cholesterol…