
Well I may be wrong but I thing that BHT stands for a high temperature treatment as used in long life milk - not sure what natural means but if heating to remove any infecting microbes is natural and it is the same as the treatment used on milk then there should be no problem unless they have changed for something less natural and more cost effective.
It seems I was wrong about heat treatment BHT stands for (Butylated Hydroxytoluene) not as yet found out what that is but it have been around a long time. It seems to be the most used preservative where fat is involved, used in most food stuff for human consumption and seems to be safe at least very much more safe than eating food without the treatment.