They took 37 men and women and asked them to estimate the age of models in photographs while wearing masks infused with the odors of grapefruit, cucumbers and grapes and then while wearing plain surgical masks.

Grapes and cucumbers produced no results, but when wearing the grapefruit masks, the participants overall estimated the models to be three years younger.

But when it was broken down by gender, the women smelling grapefruit registered no perceptible difference in the models' ages, while the men guessed them to be six years younger.