Honey is known for its many healing and therapeutic properties in all kinds of ailments, illnesses and beauty treatments. According to Ayurveda, it is one of the rare products that has the tendency to take on the property of whatever it is mixed with. This is perhaps one of the reasons why honey alone is never recommended as a remedy for anything. It is always mixed with something, because it enhances the impact of that particular thing. If it is recommended that you mix honey and onion juice to take care of baldness, it is quite a correct recommendation. The reason for this is that onion juice is responsible for growing new hairs. If honey is mixed into it, the possibility is that the honey will merely enhance and improve upon the properties of onion juice.
To answer the first part of your question, there is no scientific evidence presented anywhere in the world to substantiate that honey has a tendency to whiten our hair. As a matter of fact, it is never recommended that honey be used on hair by itself either. Honey is always recommended to be used when mixed with another product, as it is in this case, with onion juice. It would be advisable for you to not try and use honey alone on your hair.
answered by M W