A recent study adds weight to the argument that dietary control of high blood pressure involves more than just cutting back on salty foods.

What role for salt?

Does excess sodium in your diet contribute to high blood pressure? Depends on who you ask-some scientists are convinced that is does, but others say that "eat less salt" is too simplistic an answer to the question of how to best control high blood pressure, or hypertension. In fact, a study reported in a recent issue of Archives of Internal Medicine adds weight to the argument that dietary control of high blood pressure involves more than just cutting back on salty foods.

Diet makes a difference

Researchers from the University of South Carolina collected diet and blood pressure information on more than 17,000 adult participants of a large US health study conducted from 1988 to 1994. Many of the "average Americans" included in this survey did not eat particularly healthful diets-on average, meals tended to be high in sodium and low in potassium and other essential nutrients. But for those who watched what they ate, diet appeared to make a difference. The men and women who consumed a diet lower in sodium and high in potassium and calcium tended to have lower blood pressure than others in the study.

This latest analysis supports the results of the recently-completed Dietary Approaches to Stop Hypertension (DASH) Study, which found that a diet lower in sodium and fat and high in low-fat dairy foods and potassium-rich fruits and vegetables lowered blood pressure in mildly-to-moderately hypertensive people.

In spite of this evidence, though, not everyone is convinced that dietary sodium affects blood pressure. Skeptics contend that only "salt sensitive" people should limit their sodium intake, and that salt restriction is unnecessary for the majority of consumers. Scientists on the other site of the argument say that there is solid scientific evidence linking dietary sodium and blood pressure in everyone, not just "salt sensitive" people. This appears to become even more important for older people, as the likelihood of high blood pressure increases with age.

Sensible diet advice

The authors of this study point out that each nutrient they analyzed had only a small effect on blood pressure levels, but that even modest dietary changes can have a major health-promoting effect over the long run. They advise consumers concerned about their blood pressure to consider their whole diet rather than to focus on one specific nutrient:

• It's not necessary to buy foods labeled as "low sodium." Instead, moderate your intake of higher-sodium foods, including chips, pickled foods, processed meats like hot dogs and bologna, and canned soups. Experiment with condiments other than salt to season foods.
• Plan meals to include at least five servings of fruits and vegetables a day. Most are good sources of potassium and other nutrients thought to help control blood pressure.
• Don't skimp on calcium-rich foods like low-fat milk, yogurt, and cheese, since this and other studies suggest that calcium may play a crucial role in moderating blood pressure. Good non-dairy sources of calcium include green leafy vegetables and calcium-fortified foods, among them some soy beverages, orange juice, and cereal.

Source

• Impact of diet on blood pressure and age-related changes in blood pressure in the US population. IM. Hajjar, CE. Grim, V. George, TA. Kotchen, Archives of Internal Medicine, 2001, vol. 161, pp. 589--593

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