The health benefits of unsaturated fats in soybean oil

When it comes to dietary fat and health, it’s the type that matters much more than the amount, and research is clear that unsaturated plant-based fats—including soybean oil—are better for health than saturated fats.[1] In fact, liquid plant oils rich in unsaturated fats are recommended by the Dietary Guidelines for Americans[2] and the American Heart Association[3] because of their potential health benefits.

Soybean oil—which is made by extracting oil from whole soybeans—is a versatile cooking oil that’s about 59% polyunsaturated fat (roughly 53% linoleic acid—an essential omega-6 fatty acid that we need to get from food—and 6% linolenic acid, an omega-3 fatty acid), 29% monounsaturated fat, and 12% saturated fat.[4]

A 2019 analysis of 30 observational studies involving 68,659 people found that high levels of linoleic acid in the body were associated with reduced risk of cardiovascular disease.[5] A 2020 systematic review and meta-analysis of 38 observational studies found that higher linoleic acid intake was associated with a modestly lower risk of death from all causes, and specifically from cardiovascular disease and cancer. This supports the potential long-term benefits of polyunsaturated fat intake.[6]

Not only does the high proportion of unsaturated fats in soybean oil make it heart healthy, but soybean oil has specifically been shown to lower “bad” LDL cholesterol.[7] In 2017, the U.S. Food and Drug Administration (FDA) authorized a qualified health claim that supportive but inconclusive scientific evidence suggests that daily consumption of about 1½ tablespoons (20.5 grams) of soybean oil may reduce the risk of coronary heart disease when replacing an equivalent amount of saturated fat.[8]

In 2018, the FDA also allowed a similar qualified health claim for oils high in oleic acid,[9] including high-oleic soybean oil, which comes from newer varieties of soybeans bred to have a higher proportion of oleic acid, a monounsaturated fat. High-oleic soybeans produce an oil containing about 75% oleic acid, 8% linoleic acid, 2% alpha-linolenic acid, and 12% saturated fatty acids.[10]

Two other benefits of high-oleic soybean oil are that it has a more neutral flavor than conventional soybean oil, plus it has a longer shelf life and is even more suitable for high-heat cooking and frying than conventional soybean oil—which already has an impressively high smoke point of about 450 degrees Fahrenheit.[11, 12] This means soybean oil can be used for higher-heat cooking methods such as roasting, baking, sautéing and frying. That’s important, because oils can become bad for you if they’re allowed to oxidize because they’re stored for too long or in improper conditions, or are used for cooking at a higher heat than they can handle.

With many Americans concerned about heart health, especially with an aging population, it’s good news that soybean oil, individually or in blends with other unsaturated vegetable oils, is an option that can support health goals whether used in food manufacturing or the home kitchen.

Citations:

1. Ludwig, David & Willett, Walter & Volek, Jeff & Neuhouser, Marian. (2018). Dietary fat: From foe to friend?. Science. 362. 764-770. 10.1126/science.aau2096.
2. U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025. 9th Edition. December 2020. [page 35]
3. https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/fats/dietary-fats
4. Food Fat and Oils, 10^th Edition. Technical Committee of the Institute of Shortening and Edible Oils, Inc. https://www.iseo.org/s/FoodFatsOils2016.pdf
5. Marklund M, Wu JHY, Imamura F, Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Fatty Acids and Outcomes Research Consortium (FORCE), et al. Biomarkers of Dietary Omega-6 Fatty Acids and Incident Cardiovascular Disease and Mortality. Circulation. 2019 May 21;139(21):2422-2436. https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.118.038908
6. Li J, Guasch-Ferré M, Li Y, Hu FB. Dietary intake and biomarkers of linoleic acid and mortality: systematic review and meta-analysis of prospective cohort studies. Am J Clin Nutr. 2020 Jul 1;112(1):150-167. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7326588/
7. Messina M, Shearer G, Petersen K. Soybean oil lowers circulating cholesterol levels and coronary heart disease risk, and has no effect on markers of inflammation and oxidation. Nutrition. 2021 Sep;89:111343. https://www.sciencedirect.com/science/article/pii/S0899900721002057?via%3Dihub
8. https://www.fda.gov/media/106649/download
9. https://www.unitedsoybean.org/hopper/fda-authorizes-qualified-health-claim-for-oils-high-in-oleic-acid/
10. Huth PJ, Fulgoni VL, Larson BT. A Systematic Review of High-Oleic Vegetable Oil Substitutions for Other Fats and Oils on Cardiovascular Disease Risk Factors; Implications for Novel High-Oleic Soybean Oils. Advances in Nutrition. 2015;6(6):674-693. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4642420/
11. https://food.ussoy.org/food-industry-solutions/high-oleic-soybean-oil
12. Typical Smoke, Flash & Fire Points, Commercially Available Edible Fats and Oils. Institute of Shortening and Edible Oils, Inc. https://www.iseo.org/s/Smoke-Fire_Chart_0310.pdf