Soybean oil is chiefly a poly-unsaturated fats rich vegetable oil. Linoleic acid omega-6 is the major poly-unsaturated fatty acid found in it. Additionally it is low in saturated fats, and free from cholesterol; making it as one of the healthiest cooking oils.
Soybean, being a vegetable oil, is a good source of plant sterols, especially ß-sitosterol. The FDA has approved the following claim for phytosterols: Foods containing at least 0.4 gram per serving of plant sterols, eaten twice a day with meals for a daily total intake of at least 0.8 gram, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease. Phyto-sterols competitively inhibit cholesterol absorption in the gut and thereby can reduce blood cholesterol levels by 10% to 15%
Soybean oil is a moderate source of anti-oxidant vitamin E. 100 g fresh oil has 8.18 mg of a-tocopherol and 64.26 mg of gamma-tocopherol. Vitamin E is a powerful lipid soluble antioxidant, required for maintaining the integrity of cell membrane of mucus membranes and skin by protecting it from harmful oxygen-free radicals.