Weird as this may sound, I suffered with sinus headaches for years until I read something by Dr. Andrew Weil. He mentioned cutting out dairy products for a while to see if anything improved. I did and amazingly the sinus problems went away. I was lactose intolerant and it inflamed my sinuses for some weird reason. Now I drink Soy milk and the only time I have problems is when the air gets really dry and I forget to turn on humidifiers in the house.