I've heard that it can cause cancer, but are there any studies that support this claim?
There several concerns related to MSG (monosodium glutamate):
- it contains sodium, so it might rise the blood pressure leading to hypertension, a risk factor of cardiovascular diseases. (1)
- it has been found to be strictly related to overweight and obesity (2), possibly because it improves the palatability of food (= it makes you feel you like it, and you want more) (3)
- in relation to cancer, I couldn't find much information about the topic. I would suggest you to visit whe webpage http://www.msgtruth.org/cancer.htm . On the same page there are several links on the right side showing connections of MSG to other diseases.