Flaxseed lowers elevated blood pressure, to a degree that significantly reduces risk for heart disease, according to a review of 15 earlier clinical trials, published in Clinical Nutrition. Researchers found that when eaten for more than 12 weeks, flaxseed lowered pressure by 3.10/2.62 mmHg on average. Earlier research shows that lowering blood pressure by 3.3/1.4 mmHg reduces risk of death from heart disease by 22 percent. The trials that were analyzed included a total of more than 1,300 people.
A common therapeutic amount of ground flaxseed is one to two tablespoons daily, starting with smaller amounts and increasing gradually, to avoid stomach discomfort from the extra fiber.