Evidence that vegetarian dietary patterns lower blood pressure (BP) comes from both population studies and randomized controlled trials in normotensive and hypertensive subjects. 2. The effect has been shown most clearly in those who keep to a strict lacto-ovo vegetarian diet characterized by a relatively low intake of saturated fat, a high polyunsaturated/saturated fat ratio, and a high intake of fruit, vegetables and other fibre containing products. Randomized controlled dietary trials suggest the effects are independent of dietary sodium, additive to that of calorie restriction, and not due to the absence of meat protein per se. Indeed, recent population studies suggest an inverse relationship between dietary protein and BP. 4. Dietary fats, fibre, potassium, magnesium and calcium do not independently seem to account for the effects. A possible role for complex carbohydrate in conjunction with the other dietary factors has yet to be fully explored.
