Yeah, it really doesn't matter what it is. There's some theories behind it. One is food allergies, but I'm pretty dubious that there is an onset of food allergies later in life. Another is that it is a sign of dementia/Alzheimer's, but that seems equally unlikely to me. If I had to take a guess, it is probably less tolerance to ANY spices...especially pepper that is common on every table. There may also be some lessening of the body's ability to regulate body temperature between the roof of the mouth and nasal passage. So the "extreme" temperature fluctuation causes the sinuses to go active.