In order for your hair to remain healthy, it needs to retain moisture and nutrients, and those are often depleted with hot tools, chemical processing, surfactants in shampoos, and daily wear and tear. It also needs protection from environmental stressors, like sun and pollution, as they cause free-radical damage. When your hair is damaged, it can become more porous, meaning it loses water much faster.

Olive oil plays a role in helping hydrate hair, but not in the way you might think: Olive oil is a monounsaturated fat. Hair actually has the ability to absorb monounsaturated fats, according to research. (According to one study, they’ve been able to document the absorption of certain oils by tracking the thinning film that surrounds the strand; and it also shows that doesn’t happen with all oils, like mineral for example, so while some smaller oil molecules can penetrate hair, some will only sit on top.)

And when olive oil is absorbed into the hair, it can actually help hair retain hydration. Retain is the key word here: “Oil is not a conditioner, only water-based products can truly moisturize your hair,” says hairstylist Gabrielle Corney. “These oils have many hair benefits, but they work best when in conjunction with a water-based hydrating cream.” Liken it to using an oil in skin care, they are most hydrating when tapped on top of a lotion or essence to help “trap” in the water.

Olive oil also contains a large amount antioxidants from vitamins E and K. Free-radical damage not only happens to the skin, but hair as well; The oxidative stress can actually cause hair to age faster, according to one study. The antioxidants will help neutralize those and mitigate any future stressors.

Other than helping retain hydration, research suggests, olive oil can also act as a lubricant for strands to reduce breakage. Shockingly, a significant amount of damage to hair can actually happen during the shower: Hair is weakest when wet, then when you add in surfactants from shampoo and the scrubbing motion, you cause friction between strands. This friction can lead to raised cuticles, stretching, and splintering. When you apply an oil before washing, the film helps minimize the chances of this.

It should be noted that these benefits only come when choosing the right type: Opt for extra virgin organic olive oil, which is the least processed and contains more of the hair-helping nutrients explained above.