Scientific American is reporting that the smell of coffee is enough to give measurable benefits in coping with stress. I have written in the past that I find some claims for aromatherapy credible. One of the claims that some aromatherapists make is that simply smelling things can have health benefits.
This is a problem area for some scientists, and the problem is a real one. The amount of any agent that you can absorb through your nose is very small indeed. There is a similar problem with homeopathy. How can diluting something make its effect stronger?
But it seems that despite the very small number of actual molecules involved, what you smell can have a profound effect on your physiology. We may not understand how it works, but we have to accept the data.
This doesn’t mean that homeopathy has to be accepted. That has not been shown to work yet, and given how long it has been practiced and how much it has been studied the overwhelming probability is it doesn’t work.