The British Navy gave rations of rum to its sailors until the 1970s. You can find a link to a bit more information on Rum and the Navy here.
At that time it was thought that rum was the reason for preventing scurvy. We now know that it was actually the citrus element (usually lime, sometimes lemon) which was added to help take the edge off the rum is the reason the drink aided in the prevention of scurvy. It was the high levels of vitamin C in the fruit that was mixed with the rum that helped.
The way the lime and lemon worked with the rum has led to the use of the citrus fruits in a lot of the famous rum based cocktails we know and love today.
In the 1800s, rum was highly revered as a go-to beauty product for its ability to clean hair and strengthen its roots. From my research, I believe you dip the ends of hair in rum to prevent split-ends. You wet your hair in rum and then leave it to soak in for 15 minutes. Then rinse off with a mild shampoo to remove the ethanol smell. It is said that rum is also used as a remedy to hair loss. The ingredients used in rum help to produce more hair when rubbed onto skin and scalp. It also helps to hydrate skin and scalp which aids with the prevention of dandruff.
Feel free to try washing your hair in rum or trying to help prevent hair loss, however I would stress the age of the rum would make no difference so leave those well aged, expensive rums for drinking!