Should Echinacea Be Taken Daily?

Can you take echinacea everyday during the cold and flu season or only during the onset of colds or flus? Also, I read on one of your question and answers about echinacea and diabetes. I have just been taken off a pill for sugar diabetes. How does this affect taking echinacea? I take one a day and just recently I took 3 a day when I started to feel like I was getting the flu. I did get the flu but was less than 18 hour duration which I think has to do with the echinacea.

It is a point of debate whether or not Echinacea should be taken daily during the cold and flu season to prevent infection. Some herbalist argue that it is most effective when taken only at the first sign of an infection. Echinacea is often recommended daily for a period of a few months to boost the immune system in a person who is regularly experiencing colds and flu. Other effective immune boosters are vitamin C, raw garlic, astragalus and fresh fruit.