I don't think this post was meant to be offensive. A lot of food contains preservatives, hormones, and chemicals now days. Those things enter your body, then can enter your blood stream and effect your entire any system in your body, including your nervous system. If you look up any website on a Paleo lifestyle (I like paleoleap.com myself) there will be post and articles on studies about why clean, or all natural, eating is good for mental health. Then never claim be be a cure though, so yes, bad choice of wording here, but if diet improves some of the things that come along with PTSD like anxiety and depression that's great. For me personally, if I'm calm, im less likely to trigger, this site helps me with that a lot now by being able to get online and read or chat.
Despite that info, I have never found a diet that stops me from having flashbacks or isolating. I will add a personal story for you. Two years ago I was triggered really bad, for weeks, when a guy I had been dating told me he had to walk away because I had an abortion befor he even knew I exsited. I actually stopped eating all together and used the gym as a place to hide as part of that. It took everything I had to go to work for eight hours and then I would leave and shut down, completely blank.
So again, bad choice of words. A cure? For a true sufferer? no, but you may have found yourself a good distraction.