High Blood Pressure (Hypertension)
The right diet is the key to managing many diseases and to improving general quality of life. For this condition, scientific research has found benefit in the following healthy eating tips.
High-Fiber Diet
Several studies have shown that adding around 7 grams of fiber per day to the diet reduces blood pressure, although other studies have not shown a benefit.High-Fiber DietSeveral double-blind trials have shown that adding 6.5–7 grams of fiber per day to the diet for several months leads to reductions in blood pressure.182,183,184 However, other trials have not found fiber helpful in reducing blood pressure.185,186 The reason for these discrepant findings is not clear.
Coffee
In some studies, coffee drinking has led to small increases in blood pressure. Many doctors tell people with high blood pressure to avoid caffeinated products.CoffeeRight after consuming caffeine from coffee or tea, blood pressure increases briefly.187,188 In trials lasting almost two months on average, coffee drinking has led to small increases in blood pressure.189 The effects of long-term avoidance of caffeine (from coffee, tea, chocolate, cola drinks, and some medications) on blood pressure remain unclear. A few reports have even claimed that long-term coffee drinkers tend to have lower blood pressure than those who avoid coffee.190 Despite the lack of clarity in published research, many doctors tell people with high blood pressure to avoid consumption of caffeine.
Monounsaturated Fats
Frying with more stable oils (such as olive oil) does not appear to increase high blood pressure risk, unlike cooking with unstable oils such as sunflower, corn, canola, and flaxseed.Monounsaturated FatsReusing vegetable oils for frying, especially oils with high concentrations of unsaturated fatty acids (such as sunflower or safflower oil) has been associated with an increased risk of high blood pressure.191 Presumably, this increased risk is due to some of the degradation products (such as lipid peroxides or polymers) that result from the excessive heating of these oils. Frying with more stable oils, such as olive oil, is not associated with an increased risk of high blood pressure.
Salt
Avoid using too much table salt, limit salty fast foods, and read labels to find low-sodium foods in your grocery store.SaltPrimitive societies exposed to very little salt suffer from little or no hypertension.192 Salt (sodium chloride) intake has also been definitively linked to hypertension in western societies.193Reducing salt intake in the diet lowers blood pressure in most people.194 The more salt is restricted, the greater the blood pressure-lowering effect.195 Individual studies sometimes come to differing conclusions about the relationship between salt intake and blood pressure, in part because blood pressure-lowering effects of salt restriction vary from person to person, and small to moderate reductions in salt intake often have minimal effects on blood pressure—particularly in young people and in those who do not have hypertension. Nonetheless, dramatic reductions in salt intake are generally effective for many people with hypertension.
With the prevalence of salted processed and restaurant food, simply avoiding the salt shaker no longer leads to large decreases in salt intake for most people. Totally eliminating salt is more effective, but is quite difficult to achieve. Moreover, while an overview of the research found “There is no evidence that sodium reduction presents any safety hazards,”195 reports of short-term paradoxical increases in blood pressure in response to salt restriction have occasionally appeared.197 Therefore, people wishing to use salt reduction to lower their blood pressure should consult with a doctor.
Tomatoes
In one study, supplementing with a tomato extract significantly lowered blood pressure in people with hypertension.TomatoesIn a double-blind trial, supplementation with a tomato extract significantly lowered both systolic and diastolic blood pressure, compared with a placebo, in people with hypertension.197 The amount of extract used was 250 mg per day (providing 15 mg per day of lycopene plus other carotenoids) for eight weeks.
Vegetarian
Vegetarians have lower blood pressure than meat eaters, partly because fruits and vegetables contain potassium—a known blood pressure–lowering mineral.VegetarianVegetarians have lower blood pressure than do people who eat meat.198 This occurs partly because fruits and vegetables contain potassium—a known blood pressure-lowering mineral.199 The best way to supplement potassium is with fruit, which contains more of the mineral than do potassium supplements. However, fruit contains so much potassium that people taking “potassium-sparing”diuretics can consume too much potassium simply by eating several pieces of fruit per day. Therefore, people taking potassium-sparing diuretics should consult the prescribing doctor before increasing fruit intake. In the Dietary Approaches to Stop Hypertension (DASH) trial, increasing intake of fruits and vegetables (and therefore fiber) and reducing cholesterol and dairy fat led to large reductions in blood pressure (in medical terms, 11.4 systolic and 5.5 diastolic) in just eight weeks.200 Even though it did not employ a vegetarian diet itself, the outcome of the DASH trial supports the usefulness of vegetarian diets because diets employed by DASH researchers were related to what many vegetarians eat. The DASH trial also showed that blood pressure can be significantly reduced in hypertensive people (most dramatically in African Americans) with diet alone, without weight loss or even restriction of salt.201 Nonetheless, restricting salt while consuming the DASH diet has lowered blood pressure even more effectively than the use of the DASH diet alone.202
Low-Sugar
Some doctors recommend that people with high blood pressure eat less sugar, as it has been reported to increase blood pressure in short-term trials.Low-SugarSugar has been reported to increase blood pressure in animals203 and humans in short-term trials.204 Though the real importance of this experimental effect remains unclear,205 some doctors recommend that people with high blood pressure cut back on their intake of sugar.
Low-Allergen
In one study, people with migraines who also had high blood pressure experienced a significant drop in blood pressure when put on a hypoallergenic diet.Low-AllergenFood allergy was reported to contribute to high blood pressure in a study of people who had migraine headaches.206 In that report, all 15 people who also had high blood pressure experienced a significant drop in blood pressure when put on a hypoallergenic diet. People who suffer migraine headaches and have hypertension should discuss the issue of allergy diagnosis and elimination with a doctor.