Scientists have discovered that one of the most common amino acids, glutamic acid, present in vegetable protein can help to lower blood pressure. Vegetables such as broccoli and cabbage are particularly high in glutamic acid, which is key in creating the umami (savoury) taste in foods. The study of 4680 people aged 40 to 59 found that the more dietary glutamic acid they consumed, the more their blood pressure fell.

This very thorough review paper examines all of the available scientific literature relating to the possible role of monosodium glutamate in provoking allergic reactions and asthma. The review concludes that these studies have failed to demonstrate a clear and consistent link between the ingestion of monosodium glutamate and the development of allergies and asthma. In their conclusions the authors state "In short, the current evidence does not suggest that MSG is a significant contributor to asthma, urticaria, angio-oedema or rhinitis".