Water & the Heart

Millions of people suffer from ailments that doctors treat by prescribing low-salt diets. The most important are congestive heart failure and many forms of kidney disease (in which the body retains too much water, to match an excess of salt). Also, salt sometimes complicates cirrhosis of the liver and possibly high blood pressure. Yet in many parts of the U.S. and Canada, says Alberta's Dr. George B. Elliott, the benefits of the low-salt diet are wiped out by the water that patients drink--water loaded with sodium in any of several salts, including sodium chloride (common salt).

Dr. Elliott reports in Circulation (published by the American Heart Association) that he sent a 71-year-old man home from Calgary General Hospital on a low-salt diet, only to have him return bloated, 30 lbs. heavier, and with his heart failing. The man insisted that he had stuck to his diet. Dr. Elliott had the man's well water tested. It contained 4,200 parts per million of sodium--as against fewer than 50 p.p.m. in Calgary's city water.

Softening for Lather. City water supplies in the U.S. and Canada, mostly drawn from fast mountain rivers, are in general safely low in sodium. But some rivers are loaded with the stuff. The Arkansas River reaches 1,770 p.p.m. in the fall and cannot be used for drinking water. Moreover, a city's river water may be hard (because of calcium and magnesium carbonates), and housewives want it soft for washing; so the engineers soften it, often by replacing the calcium with sodium. One eminent cardiologist at a Midwestern hospital was puzzled when his heart-failure patients suddenly got worse and proved harder to treat. The hospital engineer, without telling the medical staff, had decided to make the laundry workers happy by softening the water with a sodium salt.

Drilling for Brine. Irrigation carries its own problems: nonsalty river water leaches out salts as it seeps through the soil, and much of it returns to streams, threatening their potability. In parts of Oklahoma and Texas, well drillers often get only a disappointing brine. Galveston's city supply is so loaded--351 p.p.m.--that newcomers say, "It's like drinking out of the bay." Private wells are the most variable. Federal geologists have found some in Kentucky with 31,100 p.p.m. and in Michigan with 66,700. Ocean water contains only 10,700 p.p.m.

At Duke University, in North Carolina, Dr. Walter Kempner, who pioneered the rigorous low-sodium regimen (as part of his famous "rice diet"), has laid down the accepted rule: "If the sodium concentration of the plain water available is greater than 20 p.p.m., distilled water should be used." Many of his patients are put on bottled water when they go home. But the brand has to be specified: some bottled spring waters are laced with salts not mentioned on the label.

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