Even though phenols and phytosterols are often thought to be healthy antioxidants, in this lab test of perilla oil, they didn’t seem to help at all in fighting free radicals.

In lab tests, the vitamin E-like compounds (tocopherols) in perilla oil are strongly linked to its ability to fight free radicals in two different ways, while the yellow pigments (carotenoids) are only linked to one of those tests.

When perilla seed oil is processed for commercial use, it loses most of its natural antioxidants—especially lutein, which disappears entirely during one step—and other important compounds like phenols and tocopherols are also reduced.