It is known that certain dietary factors contribute to keeping a healthy and normal blood pressure, such as avoiding salt and eating plenty of high fiber vegetable, fruits and grains.  But now, research has revealed that there is a certain flavor-enhancing compound found in all vegetables which could be one of the reasons why the "five portions a-day" diet protects people against heart disease.  What they found is that vegetables such as broccoli and cabbage are particularly high in a chemical called glutamic acid which creates the fifth taste sense known as 'umami' - otherwise known as 'savory'.  

Many people know this flavor as the one that also comes from MSG, a flavor enhancer commonly used in Chinese food and snack foods.  Umami flavor is strongest when combined with aromas (e.g., monosodium glutamate and garlic), a result leading to speculation that glutamate may stimulate umami effects by acting simultaneously with the aromas, texture, and appearance of food.  Other common natural sources of the umami flavor include beans, whole grains including whole grain rice, breads and cereals, soy products such as tofu and durum wheat which is used to make pasta.  

The study of 4,680 people aged 40 to 59 found, on average that the more of the savory substance they consumed the more their blood pressure fell. The new research suggests glutamic acid may partly explain the link between vegetable protein and lower blood pressure.  Future steps will be to reproduce this finding in other studies, and investigate how glutamic acid might exert an effect on blood pressure.   Interestingly, MSG has been linked to high blood pressure but this may be due to the salt content in it.  In the meantime, this much is clear: broccoli and cabbage are good for you so until the final results are in, feel free to chow down to keep blood pressure low and healthy!