DASH Diet Reduces Sodium and Lowers Blood Pressure

The DASH Diet

A diet rich in fruits, vegetables, and low-fat dairy products and limited in total and saturated fats, plus reduced dietary sodium, lowers blood pressure levels in all people, according to a new analysis of a government-sponsored study.

The diet also limits red meat, sweets, and sugar-containing drinks. It is rich in potassium, calcium, magnesium, fiber, and protein.

The Dietary Approaches to Stop Hypertension (DASH) study is supported by the National Heart, Lung, and Blood Institute (NHLBI).

Prior studies have found that besides blood pressure, the DASH diet lowers blood levels of low-density lipoprotein (LDL), the "bad" cholesterol, and the amino acid homocysteine, both of which may increase the risk of heart disease.

Earlier research also has found that reducing dietary sodium alone lowers blood pressure.

The latest analysis showed that the DASH diet plus reduced dietary sodium lowers blood pressure in a wide variety of people, including those with and without hypertension or a family history of hypertension, older and younger adults, men and women, blacks and other races, and obese and non-obese individuals.

In addition, the combination lowered blood pressures in people with high or low physical activity levels, large or small waist circumferences, and high or low annual family incomes or education levels.

"This new study underscores the blood pressure-lowering effects of a reduced intake of salt and other forms of dietary sodium," says NHLBI Director Claude Lenfant, M.D. "Earlier research on the link between sodium and blood pressure had given conflicting results in various population groups.

Now, we can say that cutting back on dietary sodium will benefit Americans generally and not just those with high blood pressure."

While the combination of the DASH diet and reduced dietary sodium produced the biggest reductions, each intervention also lowered blood pressure for all groups when used alone, according to the study, published in the Dec. 18, 2001, issue of the Annals of Internal Medicine.

"Adopting these measures could help millions of Americans avoid the rise in blood pressure that occurs with advancing age," says Frank Sacks, M.D., professor of cardiovascular disease prevention at the Harvard School of Public Health and chairman of the DASH steering committee.

The new data come from the DASH-Sodium study, a multicenter, 14-week randomized "feeding" trial in which all food was provided to participants.

It involved 412 participants, ages 22 and older, and who had systolic blood pressures between 120 and 160 mm/Hg and diastolic blood pressures between 80 and 95 mm/Hg.

Fifty-two percent of the participants were women and 48 percent men. Forty-one percent had hypertension and 59 percent did not.

For three months, participants ate either the DASH diet or a typical American diet. Weight was kept stable.

During the study period, each group followed three different intakes of dietary sodium for one month each in random order. The sodium levels were 3,300 milligrams a day (the average level consumed by Americans), 2,400 milligrams a day (the upper limit currently recommended by the National High Blood Pressure Education Program), and 1,500 milligrams a day.

The largest blood pressure differences occurred for those on the DASH diet with a daily sodium intake of 1,500 milligrams compared with those on the "typical" diet with a sodium intake of 3,300 milligrams.

The Basics of the Dash Diet is : Heart-Smart Substitutions

More information is available on the NHLBI website where you can download a book on the dash diet and healthy eating plan.