LONDON – A reduction in salt intake for four or more weeks led to significant falls in blood pressure in both hypertensive people and those with normal blood pressure, irrespective of sex and ethnic group, according to a meta-analysis of randomized trials published on-line April 5 in theBritish Medical Journal.

The meta-analysis, which included 34 trials that had 3,230 people, showed the mean change in urinary sodium was equivalent to a reduction of 4.4 grams of salt per day. With this reduction in salt intake, the mean change was minus 4.18 mm Hg for systolic blood pressure and minus 2.06 mm Hg for diastolic blood pressure.

Salt (sodium chloride) generally is about 39% sodium. The Dietary Guidelines for Americans 2010 recommends a reduction in daily sodium intake to 2,300 mg per day. A further reduction to 1,500 mg per day is recommended for people age 51 and older and people of any age who are African American or have hypertension, diabetes or chronic kidney disease.

The Consensus Action on Salt and Health, a scientific group based in the United Kingdom, has a current target of reducing salt intake to an average of 6 grams a day for adults.

The meta-analysis included researchers from Queen Mary University of London and an affiliated hospital of LuZhou Medical College in China.

“The current recommendations to reduce salt intake from 9-12 to 5-6 grams per day will have a major effect on blood pressure, but a further reduction to 3 grams a day will have a greater effect and should become the long-term target for population salt intake,” the researchers said.