"Effect of systemic monosodium glutamate (MSG) on headache and pericranial muscle sensitivity :
"We conducted a double-blinded, placebo-controlled, crossover study to investigate the occurrence of adverse effects such as headache... there was a significant increase in reports of headache..." SOURCE
In addition, if you add oil to your cooked and drained pasta, it absolutely stops it from sticking vs. not adding oil. Just don't add it to the water, as it's just wasteful.