Oil swishing — an ancient practice meant to whiten teeth — has recently become an increasingly popular trend among Americans hoping to naturally whiten their teeth.

But does it really work?

By swishing coconut oils around one’s mouth similar to a mouthwash, ancient peoples in what is today eastern India practiced oil swishing — or oil pulling — as a way to freshen breath and clean teeth and gums, according to the Tech Times.

While modern-day proponents of oil swishing list a number of its benefits — such as preventing tooth decay and gum disease — no scientific studies have actually been conducted to prove or disprove these claims.

“I don’t think the oil has an intrinsic effect other than the removal of plaque. It’s hard to find a study that states that. Anything that swishes around for 20 minutes may have some effect, even water,” Joseph Banker, a cosmetic dentist in Westfield, N.J., told WebMD.

Until studies are conducted that can scientifically prove the benefits of oil swishing, it might be best to take this trend with a grain of salt. However, it’s very unlikely that swishing coconut oil has harmful effects, the Tech Times reports.

Tooth decay and gum disease are most often caused by plaque, which is created when food and the bacteria of the mouth come into contact. Approximately 23% of adults in the United States aged 20 to 64 have untreated tooth decay. No matter which method you choose to prevent tooth decay, it’s extremely important to make sure you keep your teeth clean.