Four major steps have been identified as ways to prevent high blood pressure: weight control, reduced salt intake, increased exercise, and reduced alcohol consumption.
Weight. Being overweight increases the risk of developing high blood pressure by two to six times; in fact, 20-30 percent of hypertension can be attributed to obesity. And Americans are getting fatter! The National Center for Health Statistics recently released data showing that the number of adults who are overweight has increased from one in four to one in three over the past 10 years. The proportion of people who are overweight increases until about age 50 for men and age 70 for women. Upper body fatness in particular raises the risk for high blood pressure. Even modest weight loss helps reduce high blood pressure.
Sodium. The most common form of sodium in our diets is salt. Sodium makes up about 40 percent of the salt compound. An easy measure to remember is that one teaspoon of salt contains about 2000 milligrams of sodium. We take in about 2500-5000 milligrams of sodium each day, greatly exceeding our daily minimum requirement of 500 milligrams. The Food and Drug Administration’s food labels now list a daily intake of 2400 milligrams of sodium as an optimal level.
There are three sources of sodium in the diet: the sodium in the form of salt added to food during cooking and at the table; sodium naturally occurring in food; and sodium added to food during commercial food processing. Most of the sodium by far comes from the third source. Estimates indicate that up to 80 percent of the daily intake of sodium is derived from the consumption of processed foods. Most of the sodium in processed foods is added to preserve or flavor them.
Exercise. The prevalence of high blood pressure is lower in more physically active or fit adults than in less active individuals. Research shows that the more active a person is, the lower the person’s blood pressure. Daily exercise is more effective than exercise performed three times per week. Low to moderate intensity exercise (walking, cycling, dancing, gardening) is as effective as higher intensity exercise in reducing blood pressure.
Alcohol. Studies show that three or more drinks per day increase blood pressure. Alcoholic drinks contain calories and can interfere with self-control, proving obstacles to weight loss efforts.
Do Other Nutrients Affect Blood Pressure?
Other nutrients that have been investigated include potassium, calcium and magnesium.
Potassium. Studies show that potassium supplementation may have a role in the prevention of high blood pressure. African-Americans seem to derive particular benefit from potassium supplementation, perhaps due to a deficient potassium intake. Although potassium is not likely to be as important as weight control and reducing sodium intake, nutritionists believe it’s a good idea to use potassium supplementation in combination with other strategies. The richest dietary sources of potassium are unprocessed foods, especially fruits, many vegetables and fresh meats.
Calcium. While an increase in dietary calcium may result in a lower blood pressure, the evidence is not conclusive because the results are clouded by other effects such as age, race, sodium intake and alcohol consumption. A prudent approach is to consume the recommended dietary allowance of 800-1200 mg per day. Dairy products are excellent sources of well-absorbed calcium.
Magnesium. There’s not enough evidence to support the use of magnesium supplementation to prevent high blood pressure. Nutritionists generally advise consuming the recommended dietary allowance of 280 mg for females and 350 mg for males. The highest concentrations of magnesium are found in whole seeds such as nuts, legumes and unmilled grains.
In summary, weight loss, a reduction in sodium intake, daily low to moderate intensity exercise, and avoidance of excessive alcohol consumption appear to be the best approaches to the prevention of high blood pressure. A strong but less conclusive case can be made for potassium supplementation. The evidence is less convincing for supplementation with calcium or magnesium. Finally, know your blood pressure. Be proactive and have your blood pressure checked at least once every two years.