The Dietary Approaches to Stop Hypertension (DASH) studies found that diets rich in vegetables can lower blood pressure to levels similar to those achieved with single hypotensive medications [23] and [24]. This protection has been attributed to the high content of antioxidants, yet large clinical trials have failed to provide evidence in support of this theory [25] and [26]. The strongest protection against coronary heart disease was associated with the consumption of green leafy vegetables (e.g., spinach, lettuce) [27]. These vegetables commonly have a high inorganic nitrate content [28]. Interestingly, the BP reduction described after ingestion of beetroot juice decreased BP only if saliva was continuously swallowed, demonstrating the critical involvement of an enterosalivary circulation of nitrate for its bioactivation [5]. Other foods rich in nitrate–nitrite are mushrooms and seaweed. Asian population, especially Japanese, consume a diverse range of mushrooms and seaweed on a daily basis. Overall, the traditional Japanese diet contains a great number of green, leafy vegetables, making it exceptionally rich in nitrate, and the daily consumption higher than in any other known diet. We therefore aimed to examine if the Japanese traditional food, reflected in ingestion of dietary nitrate, affects plasma nitrate/nitrite and arterial blood pressure.