Oil pulling proponents claim that the swishing activates the enzymes and draws the toxins out of the blood. They suggest that bacteria hiding under crevices in the gums and in pores and tubules within the teeth are sucked out of their hiding places with oil pulling and held firmly in the solution, until it is spit out.
However despite the fact that there are a few websites that suggest there is scientific evidence to “prove” this technique works, the studies that do exist, are unreliable for a number of reasons, including cultural bias, the lack of demographic information, the misinterpretation of results due to small sample size, the absence of negative controls, and the lack of blinding. While it doesn’t appear to harm the teeth, what little scientific evidence exists shows that it is probably not as effective as standard mouth wash, and what benefit it has is likely entirely due to the mechanical act of swishing to remove particles and bacteria from teeth and gums. Oil pulling for general health or any other indication is pure pseudoscience.
One big risk identified in the research that is associated with oil pulling is Lipoid pneumonia. Lipoid pneumonia is a chemical lung disease caused by inhaling small amounts of oil. Since oil pulling calls for long periods of time with swishing oil, the risk of lipoid pneumonia is a serious complication.
More research is needed in this practice that is becoming popular, but to date oil pulling therapy has insufficient peer-reviewed scientific studies to support its use as a supplementary oral hygiene practice.