Celery contains a phytochemical called phthalide that relaxes the tissues of the artery walls to improve blood flow and lower blood pressure, according to the Cleveland Clinic. In addition, celery stalk is low in salt and contains other nutrients, such as fiber, magnesium and potassium, that also help reduce blood pressure.
The recommended daily dose of celery to regulate blood pressure is four stalks, or 1 cup of chopped celery, states the Cleveland Clinic. Recent media attention has purported the benefits of celery seed for reducing blood pressure; however, doctors recommend eating the celery plant for substantial health benefits. While one recent study shows that consuming celery seed extract improves blood pressure in patients with low or moderately elevated blood pressure, the literature about plant extracts more broadly suggests that they have little to no benefit and may even be harmful.
Celery alone is insufficient to reduce blood pressure, according to the Cleveland Clinic. A more effective diet includes a mix of vegetables, fruits, whole grains, beans, seeds, nuts and vegetable oils that ensure that the body gets the potassium, calcium, fiber and protein it needs to regulate blood pressure. As much as possible, a blood pressure-friendly diet excludes sweets, salty foods, sugary drinks and red meats.