Hello GJ1978,
Welcome to the NeuroTalk Support Groups.

Allergies or sensitivities to certain foods or chemicals in the environment can indeed contribute to an exacerbation of tics.

You could also check out the TS Forum here.
http://neurotalk.psychcentral.com/forum25.html

If you do a search in there for "allergies" just one example, you'll find many older posts regarding these issues. http://neurotalk.psychcentral.com/search.php

There are some excellent resources in the "Sticky" posts at the top of this forum too.
Useful Websites and Resources for Anxiety & OCD

http://latitudes.org/finding-trigger...s-a-must-read/
Finding Triggers for Tics & Tourette Syndrome

Modifications to diet or changing issues in our environment certainly do help some people with tics and ocd, but everyone is different so what may help one person isn't necessarily going to help another. It doesn't (in my opinion) mean that you're going to suddenly stop having tics or oc issues, but if you are allergic or sensitive to various chemicals or foods, it could mean that you can decrease your symptoms. A cold in the nose, for example, can exacerbate tics, or a sprained ankle. It's different for everyone.

If you are presently taking medications please don't stop them without talking to your doctor.